Glossary

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A

Adams-Stokes syndrome

Recurrent episodes of syncope and additional neurological symptoms caused by a drastic decrease in cardiac output due to particularly low heart rate.



Adrenalin (Epinephrine)

A hormone, which is excreted from the Adrenal gland. It is known as “stress” hormone, because its secretion increases during stress and exertion. It causes changes in the body, such as accelerated pulse rate, dilatation of the pupils, and increased blood flow into the muscles of the lower extremities. It is also dubbed danger hormone, and indeed the physical changes effected by it prepare the body to react in situations of threat (for example pumping more blood to the leg muscles prepares the body to flight). Used medically, the hormone serves for resuscitation, in Asthma (dilates bronchi), in surgery (constricts blood vessels and reduces bleeding) and more.



Aneurysm

Sometimes Atherosclerosis can cause weakening of the arterial walls and as time goes by, this wall can protrude in the attenuated area.

The protruding area is called aneurysm and it is exposed to more hazards than normal areas: rupture because of wall weakness, exertion of pressure on other vessels due to the unnatural protrusion and creation of blood clots in the aneurysm with the dangerous possibility of embolism (a thrombus thrown from the heart to a distant location, where it can cause damage).

Sometimes surgical intervention may be necessary.



Angina Pectoris

A condition characterized by recurrent episodes of distressing chest pain resulting from ischemia, i.e. discrepancy between oxygen consumption and oxygen supply to the heart at a given moment. The main reason for Angina Pectoris is occlusion of a Coronary artery (artery of the heart) by an Atherosclerotic plaque, but other cases are also possible, where pains are due to a spasm of a Coronary artery caused by contraction of the smooth muscle in its walls.. At early stages of the disease, the pain appears mainly after strain or excitement accompanied by pulse acceleration. In more advanced stages, pains can appear after slight efforts or even at rest.



Antiphospholipid Syndrome (APS, Hughes syndrome, sticky blood syndrome)

People suffering from this syndrome expose an increased tendency to thrombosis.

Thrombi usually occur in the lower extremities, but other body regions can be involved as well.
According to one theory, this syndrome is an auto-immune disorder with impaired immune system causing an attack against the body’s own tissues and organs.
It can be diagnosed by blood tests. Treatment includes anti-coagulants.



Aorta

A blood vessel of arterial type, which is the largest artery in the human body. It originates from the left ventricle of the heart and ends in the pelvis, where it divides into two femoral arteries, each of which supplies one of the lower extremities, the right and the left, respectively. Along its entire course, smaller arteries originate from the aorta, which supply oxygenated blood to all body organs.



Aortic regurgitation

A defect of the valve located at the offspring of the Aorta from the heart. As a result of this valvular defect, leakage of blood from the Aorta back to the left ventricle during the diastole takes place. In severe cases symptoms, such as shortness of breath, chest pain and enlargement of the heart, can develop. If necessary, surgical treatment is applied.



Aortic stenosis

Narrowing of the valve between the outlet of the left ventricle and the Aorta.

This is the most frequent Valvular disease. Because the stenosis makes blood flow from the left ventricle into the Aorta more difficult, the voiding of the left ventricle is impaired. This may cause symptoms of Angina Pectoris, shortness of breath during exertion and fainting. On heart auscultation, a murmur during the systole is heard, which ensues because of the compromised blood flow through the narrow valve.



Aortic valve

The Aortic valve is located at the outlet of the Aorta and delimits the Aorta from the left ventricle.

The Aortic valve enables passage of blood through it into the Aorta during systole, the phase of contraction of the left ventricle.

During diastole, when the ventricle is relaxed and the pressure in it decreases, there is risk of reverse blood flow from the Aorta (because the pressure therein is higher) into the left ventricle. The Aortic valve is here to prevent such back flow.

In instances when the valve is damaged or does not close properly, leakage into the left ventricle (regurgitation) can occur. Such leak reduces the amount of blood pumped into the Aorta on the one hand and constitutes an additional load for the left ventricle on the other hand .



Arrhythmia

Disorder in the normal heart rhythm. Any disturbance in the creation of the electrical stimulus or its conduction can cause irregular heart rate (arrhythmia). Arrhythmias can be paroxysmal and intermittent or chronic. They can originate in the upper cardiac compartments (vestibules or atria) or from the lower compartments (ventricles). Arrhythmias can be rapid or slow, without any clinical significance or life-threatening. The therapeutic approach depends on the sort, risk level, frequency of the appearance of the disturbance and its clinical consequences.



Arteriosclerosis (calcification of arteries)

Sedimentation of calcium into the arterial walls. This process or condition is different from atherosclerosis.



Artery

A blood vessel that normally carries oxygen-rich blood from the heart to other body organs.

One exception is the Pulmonary artery, which, on contrary, carries oxygen-depleted blood from the right part of the heart to the lungs.

The arterial walls include, among others, smooth muscle fibers, which enable contracture and relaxation of the vessel. These muscular fibers are under control of the nervous system.



Artificial pacemaker

A device used for generating electrical signals and maintaining regular heart rhythm in patients suffering from a disturbance in electricity generation or transfer in the heart.

The need for an artificial pacemaker can be temporary and transient or chronic and permanent.

There are external pacemakers (the pulse generation takes place outside the chest), which are usually used for pre-hospitalization period.

In permanent pacemakers, the battery is implanted subcutaneously and the electrodes are implanted into the heart.



Artificial respiration

A resuscitation activity aimed at preserving the gas exchange in the lungs. It can be accomplished by various methods, beginning with mouth to mouth respiration and ending by the use of very sophisticated respiration machines.



Asystole

Finding of a flat line on ECG, meaning that electrical and mechanical activity of the heart is absent. Practically, during Asystole the electrical stimulation system of the heart does not trigger or conduct electrical stimuli, the muscle does not contract, there is a dramatic decline in cardiac output and the result is loss of consciousness, respiratory arrest and death. The treatment is defined as reanimation and consists of external cardiac massage, mechanical respiration and intravenous injections of medicines



Atheroma

A lipid sediment narrowing the lumen of an artery. It is formed as part of a disease known as Atherosclerosis.



Atherosclerosis

An arterial disease characterized by the development of lipid plaques in the inner lining of the artery. The lipid sediments are accompanied by local inflammatory processes and by accelerated division of muscle and connective tissue cells; the final result is a plaque narrowing the lumen of the arterial vessel and diminishing the amount of blood that can pass through it at any given time. The clinical effects secondary to the existence of such a plaque in an artery can range from total absence of symptoms, through an expected and gradual clinical manifestation (development of Angina Pectoris in stress situations only) and up to a violent and unexpected event of heart attack.



Atrial fibrillation

A frequent rhythm disturbance (most frequent in elderly patients) originating from the atria and resulting in ineffective atrial contractions. It can result in rapid heart rhythm.

Due to the ineffective contraction of the atria, cardiac output is reduced and this can be clinically manifested by congestive heart failure, especially in patients with a significant background heart disease.

In addition, Atrial Fibrillation harbors an increased risk of formation of thrombi in the heart.

For this reason, people with chronic or frequent paroxysmal Atrial Fibrillation are often treated with drugs preventing thrombus formation, such as Coumadin.

Atrial fibrillation can be reverted by drugs or by electrical shock (Cardioversion).



Atrio-ventricular (AV) node

A group of cells within the Myocardium serving as a relay station for electrical signals transferred from the atria to the ventricles.

The existence of these cells is helpful for the synchronous and coordinated transfer of electrical signals from the atria to the ventricles and thus for preserving effective contraction of all heart compartments.



Atrium

The upper heart compartments are called atria (vestibules).

They are separated from the ventricles by unidirectional valves.

The right atrium receives blood from the large vein system (Superior and Inferior Vena Cava) After having been collected from all body organs, this blood has low oxygen content. From the atrium it is transported through the Tricuspid valve to the right ventricle and from there, during the ventricular systole, to the Pulmonary artery for oxygenation.

The left ventricle receives oxygenated blood from the Pulmonary veins and it voids through the Mitral valve to the left ventricle and from there, during systole, to the Aorta.

The natural cardiac pacemaker, the Sinus, is located in the right atrium and from there electrical impulses are propagated to different sites in the heart.

Various conditions, such as valvular diseases, pulmonary diseases and more, can affect the atrial status.



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b

Balloon angioplasty (coronary angioplasty, PTCA)

A therapeutic procedure performed during catheterization (Coronary Angiography) aimed at dilating a Coronary artery with stenosis caused by an atherosclerotic process. The dilatation is performed by inflating a balloon and exerting pressure upon the lipid plaque in the arterial wall.

The ballooning procedure can often replace the necessity of performing bypass surgery and an open heart operation may thus be spared from many patients, although not every lipid plaque can be dilated by this method.

One of the undesired adverse events of this procedure is re-occlusion of the dilated artery after a relatively short time. To minimize the chance of re-occlusion, stents are used.



Balloon catheter, balloon-tip catheter

A catheter with a balloon at its tip used for dilating a blood vessel or a narrowed intestine or for draining the content of an organ, such as the urinary bladder.



Bigeminy

Heart rhythm characterized by intermittent appearance of one normal beat (originating from the Sinus) followed by a second beat of atrial or ventricular origin.



Block

Disturbed electrical conductance in any part of the electrical conductive system of the heart.

Causes for the appearance of a block can be temporary and transient or chronic and permanent.

The chronic condition is more frequent in old age.

The location of a block in the conductive system may be important for the clinical effect resulting thereof.

Blocks in some sites may be unnoticeable and are detected accidentally when ECG is recorded. On the other hand, blocks can cause significant slowing of the heart rate (Bradycardia), which is accompanied by symptoms.

Possible treatment modalities depend on the clinical manifestation, the duration of the disorder, its causative factor and its risk potential.



Blood lipids

See entry: Cholesterol



Blood pressure

Pressure exerted by blood on the blood vessels during flow.

Blood pressure is measured during two distinct phases: The first phase, the systolic pressure, is measured during the contraction of the heart and it is mainly affected by the strength of the contraction. The reading is called systolic blood pressure value.

The second phase is the diastolic pressure, during the relaxation phase of the heart and it reflects mainly the resistance of the vessels to flow, or in other words the elasticity of the vessel, for which the measurement is taken. The reading is called diastolic blood pressure value.

Blood pressure is expressed in units of mm Hg (height of mercury column in millimeters).

The instrument used for this measurement is called sphygmomanometer and blood pressure is usually measured in the brachial artery (in the arm).

A cuff is put on the arm and inflated until the pressure exerted on the artery is higher than the systolic value. Thus, in fact, blood flow in the artery is interrupted.

In the next stage, the pressure in the cuff is slowly released and at the same time pulse sounds are auscultated by means of a stethoscope.

When pulse can be heard again (blood flow is restituted), the artery pressure is equal to the cuff pressure. This point is the systolic value. The point in which pulse sounds disappear again is the diastolic pressure value.

Blood pressure tends to be affected by age, gender, race, body weight, nutrition, genetics and more.

Blood pressure values may also differ at different day times and depend on exercise, season of the year and other factors.

If blood pressure values on repeat measurements exceed 140/90, the condition is called Hypertension, and follow-up and treatment are mandatory.

 



Blood vessels

Tubes of various calibers for blood transport from or to the heart and the various organs of the body.

There are arterial and venous blood vessels. As a rule, the arterial system carries oxygen-rich blood to various body organs and the venous system is a draining system carrying low oxygenated blood from the organs back to the heart and from there to the lungs for oxygenation.

An exception thereof are pulmonary vessels, in which oxygen-low blood is, on the contrary, transported by arteries (branches of the pulmonary artery) and oxygen-rich blood is transported back to the heart by pulmonary veins.

Veins and arteries differ not only by their purpose and function, but also by their anatomical structure.

Arteries are more elastic and possess a muscular layer, thus being able to contract and expand.

 



BMI (body mass index)

An index for the evaluation of the body weight considering height and gender. The value is calculated by dividing the body weight in kilograms by the square of height in meters.

The desired value for women is between 22 and 25 and for man between 23 and 26.

Higher values mean overweight.

If the values exceed 40, we are dealing with morbid obesity.

As a rule, overweight is one of the risk factors for cardiac disease.



Bradycardia

Slow heart rate, less than 60 beats per minute.

Bradycardia can be physiologic and normal, for example during sleep or in athletes.

However, bradycardia can also constitute a pathological state, resulting from a problem in the generation of the electrical stimulus in the heart or in impaired electrical conduction. The clinical significance depends on rate (how slow the rhythm), on duration of the disturbance and on the general state of the patient.

If necessary, the treatment may be by medication or by implanting a pacemaker.



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c

C.P.K.

One of the cardiac markers, protein substances (enzymes), the serum level of which increases after a heart attack, and therefore suitable as one of the parameters indicating Myocardial Infarction.

CPK is found in many tissues of the body, mainly in skeletal muscles, and therefore its increase does not necessarily mean cardiac damage. In fact, any muscular trauma, even the slightest (for instance after an intramuscular injection) can significantly increase CPK levels.

Therefore, in the examination of CPK when a heart attack is suspected, an iso-enzyme, called CPK-MB, is evaluated. Increasing levels of this iso-enzyme are much more specific for cardiac damage.



Capillary

Small blood vessels that constitute the junction area between the arterial and the venous system.



Cardiac arrest (cardiopulmonary arrest)

This is a state, in which the pump action of the heart comes to a stop.

Cardiac action can cease due to rhythm disorder of the ventricular fibrillation type (a very rapid heart rate with complete lack of synchronization between the muscle fibers of the heart and a resulting lack of efficacious contraction) or when asystoly (total cessation of electrical and mechanical activity of the heart) is present.

Symptoms develop rapidly and include: loss of consciousness, respiratory arrest and cessation of pulse. Without treatment, irreversible brain damage ensues in a matter of minutes followed by death.

The principal mode of treatment (resuscitation) includes: external cardiac massage, mechanical ventilation, interrupting the rhythm disorder by electrical shock (defibrillation) and proper medications.



Cardiac block

see entry: Block



Cardiac CT (virtual catheterization)

An imaging examination of the Coronary arteries by means of CT scan.

The purpose of the examination, like in usual catheterization, is the localization of stenoses and occlusions in the Coronary arteries.

The big advantage compared to usual catheterization is the fact that it is not an invasive procedure.

Between its disadvantages: limited imaging potential and the fact that it is an exclusively diagnostic examination and does not allow a consecutive therapeutic intervention if such is necessary.



Cardiac hypertrophy

The term “hypertrophy” refers to an enlargement of an organ resulting from the increase in the size of the cells, but not in their number. Hypertrophy of different heart compartments can occur when these compartments are working against increased load. For example, in patients suffering from unbalanced Hypertension for a prolonged time, the left ventricle of the heart must overcome increased resistance, which requires more effort from the ventricular muscle.

As a result of this chronic burden, the cells of the left ventricle increase in size and this state is called left ventricular hypertrophy (LVH).

Although hypertrophy is a defense mechanism enabling the heart to respond to greater load, at the end it requires its toll and hypertrophy of the left ventricle is associated with increased cardiovascular mortality.



Cardiac membrane

See entry: Pericardium



Cardiac Output

The quantity of blood that the heart pumps in one minute. It is the product of the stroke volume (the blood quantity sent to the circulation by each heart beat) multiplied by heart rate (number of beats per minute).

At rest, cardiac output is approximately 5 liters per minute. During physical strain, cardiac output increases with exertion and can reach even 35 liters per minute.



Cardio-vascular

Pertaining to heart and blood vessel system.



Cardiology

Research of cardiac function. Science concerned with the anatomy, functionality and diseases or pathological conditions of the heart.



Cardiomegaly (megacardia, megalocardia, enlarged heart)

See entry: Hypertrophy



Cardiomyopathy (myocardiopathy)

A chronic disease afflicting the heart muscle and causing structural and functional myocardial changes.

It may cause heart enlargement, cardiac insufficiency, increased tendency to rhythm disorders, formation of thrombi (blood clots) and more.

Causes can vary and include: congenital or hereditary disease, exposure to viral infection, alcoholism, storage diseases and more.



Cardiopulmonary resuscitation (CPR)

Performing emergency procedures aimed at preserving (at least partially) the cardiac and pulmonary functions.

The treatment includes external heart massage, by which sort of “squeezing” of the heart from outside is performed. By this squeezing partial filling and emptying of the heart is achieved.

In addition, resuscitation includes artificial ventilation that preserves oxygen vs. carbon dioxide exchange, which is the normal function of the lungs.

The term advanced resuscitation refers to medical treatment and electrical shock applied together with basic resuscitation procedures.



Cardioversion

Using electrical shock for stopping rapid rhythm disorder. In most cases, this procedure is applied when the rhythm disorder deteriorates the patient’s state and requires immediate stop.

In contradistinction to the term “Defibrillation”, which designates treatment by electric shock in Ventricular Fibrillation, a lethal rhythm disorder, the term “Cardioversion” is reserved for electrical treatment of rapid rhythm disorders that are not Ventricular Fibrillation.



Cholesterol

Cholesterol is a kind of fatty substance that is produced by the body (mainly in the liver). It is the basic material, of which various hormones of the body are composed. It is also a component of food, found mainly in food products including animal fat.

The total Cholesterol level is normally defined as low if it is below 220 mg/dL.

To maintain a healthy heart, the recommendation is reducing this level below 150 mg/dL.

Study results indicate that by reducing total Cholesterol level by 1%, the risk of acquiring a cardiac disease diminishes by 2%. For example, reducing the total Cholesterol from 200 to 180, decreases the risk of acquiring a heart disease by 20%.

It is customary to distinguish between LDL (low density lipoprotein), called “bad cholesterol” and HDL (high density lipoprotein) called “good cholesterol”.

The terms HDL and LDL refer to the protein component that carries and transports Cholesterol in the circulation.

LDL cholesterol (the “bad cholesterol”) is known to be involved in the Atherosclerotic process.

Its recommended high limit for persons with a high risk for a heart disease is 130 mg/dL.

In people with an existing heart disease, the targeted level of the “bad” cholesterol is 70 – 80 mg/dL.
HDL cholesterol has a protective effect on the cardiac arteries.

The level recommended for women is more than 45 mg/dL and for men more than 55 mg/dL.

Studies demonstrate that an increase by 1% of the “good” cholesterol is associated with a 3-4% decrease in risk of acquiring a heart attack. It is known that aerobic physical activity helps in increasing the “good” Cholesterol level.



Collateral circulation

Circulation bypassing the main (occluded) vessels. Such circulation develops when an occlusion of a main vessel exists.

It is part of the correction and compensation mechanism, by which the growth of natural vessels bypassing the occlusion is promoted.

Such natural bypasses are only partially efficient and seldom constitute an adequate solution of a significant atherosclerotic problem.

Regular aerobic sport activity helps in the development of such natural bypasses.



Congenital Heart Disease

Congenital diseases that cause anatomical or functional damage to the heart.

Some of these instances are detectable by prenatal diagnosis and some of them are amenable to surgical solutions.



Congestive heart failure (CHF)

Reduced ability of the heart to fulfill its function as an efficient pump that accepts blood and pumps it to the various organs of the body. Usually, this is a result of a previous damage that the heart suffered. Such damage can be acute and sudden, as in the case of a heart attack or chronic and gradual, such as caused by Hypertension (high blood pressure) not treated for many years and with time causing structural heart changes. This functional insufficiency causes symptoms due to ineffective blood supply, such as weakness and difficulties to exercise on the one hand and symptoms due to congestion of organs with fluid overload due to inefficient blood evacuation from them by the heart (for example, Pulmonary Edema), on the other hand.



Cor pulmonale

Anatomical changes in the right part of the heart caused by increased blood pressure in the pulmonary vasculature.

This is usually a result of a chronic pulmonary disease



Cor pulmonale (pulmonary heart disease)

Enlargement and failure of the right ventricle caused usually by chronic lung disease that led to increased intrapulmonary pressure and finally to structural and functional changes of the right ventricle of the heart.



Coronary angiography (heart catheterization, cardiac catheterization)

Imaging technique of Coronary arteries by serial X-ray photographs following injection of contrast medium. This procedure enables identification of stenotic or occluded segments in the Coronary arteries as well as cardiac imaging for identification of anatomical defects and alterations.

The procedure is usually performed under local anesthesia by inserting a catheter into a Femoral blood vessel and its advancement up to the area to be demonstrated.



Coronary artery

The Coronary system is responsible for the supply of oxygen-rich blood to the heart muscle itself. The system originates from the Aorta, and the main Coronary arteries are: Left Main )LM), Left Anterior Descending )LAD), Circumflex (CX) and Right Coronary Artery (RCA).

Different arteries supply blood to different areas of the heart.

The coronary system is more strongly exposed to the development of Atherosclerosis compared with other arterial systems and this fact explains the enormous incidence of Ischemic heart disease.



Coronary artery

One of the arteries belonging to the system nourishing the heart muscle itself and responsible for the oxygen supply to the heart.

This arterial system originates from the Aorta.

It is composed of three main arteries: RCA, LDA and CIRCUMFLEX and their branches.

The Coronary system is one of the arterial systems in the body most strongly exposed to the Atherosclerosis process.



Coronary Heart Disease, Ischemic Heart Disease (IHD ,CHD)

A disease characterized by decreased blood flow in the coronary arteries resulting from stenosis.

In most cases, these stenoses (narrowing) is caused by Atherosclerosis, a process in which lipid plaques are formed upon the arterial wall, whereby the lumen is narrowed and less blood can flow in them at any given moment.

If the oxygen requirement at a given time exceeds the possible supply by the stenosed Coronary artery, relative oxygen deficit ensues. This deficit is called Ischemia.

Ischemia can cause biochemical, electrical and temporary functional alterations in the heart and the patient usually experiences distressing pressure pain in the front of the chest, which is known as Angina Pectoris.

The course of Ischemic disease depends on the extent of the lipid plaques, their localization and the processes occurring in them.

If a lipid plaque grows slowly and is stable, gradual appearance of symptoms is the rule, known as stable Angina Pectoris. The characteristic trait of this form of the disease is the appearance of Ischemia when the demand for oxygen exceeds the supply.

Because the highest oxygen requirement occurs during strenuous heart action, physical exercise or mental stress are known triggers for the appearance of ischemic pain.

If processes inside the lipid plaque cause the rupture of its envelope with creation of a blood clot (thrombus) on its surface, the course of ischemic disease can become stormy and result in myocardial infarction, rhythm disturbances and even sudden death.



Coronary risk factors

A medical condition, lifestyle or environmental threat that increases the statistical risk for the development of atherosclerosis in the cardiac vasculature, i.e. the Coronary arteries.

Among these risk factors the following are usually included: advanced age, male gender (during the procreative years, women are usually better protected then men), genetic factors (family history), Hypertension, Diabetes, high blood lipid levels, obesity, lack of physical activity, smoking and mental stress.



Cyanosis

Bluish or livid color of the skin and the mucous membranes due to low oxygen content of the blood.

This is particularly conspicuous in the lips and nails. Cyanosis can appear in various medical conditions, for which the underlying course is low oxygen saturation of the blood, as for example lung diseases, heart defects, in high geographic regions and more.

Cyanosis in inner parts of the lips (that are not exposed to cold), cheeks, tongue and conjunctiva of the eyes, can evidence reduced oxygen saturation of blood secondary to pulmonary or cardiac disease.

Cyanosis appearing in external parts only, such as finger tips, the tip of the nose or the outer parts of the lips can be due to decreased blood flow into the skin because of its exposure to low temperature.



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d

Defibrillation

An electrical shock applied to the heart as treatment aimed at an immediate stopping of rapid rhythm disorders, which constitute a life threatening condition (for example Ventricular Fibrillation).



Defibrillator

A medical device destined for exerting an electrical shock to the heart for immediate stopping of rhythm disorders. Electricity is conducted by means of metallic plates located at predefined points on the chest. Some defibrillators are equipped with an automatic mechanism capable of recognizing a rhythm disorder and initiating the electrical shock accordingly. Some other subcutaneously implantable defibrillators deliver the electrical shock directly to the heart when dangerous rapid rhythm disorders are detected.



Diabetes mellitus

Diabetes is a metabolic disease characterized by high glucose (sugar) concentration in serum and in urine.

The Latin name Diabetes mellitus means “sweet urine”.

The main problem underlying Diabetes is relative or absolute deficiency of the hormone Insulin.

This hormone is produced in the pancreas and is secreted into blood as a reaction to increasing sugar levels.

Insulin is responsible for glucose transfer from the blood into various body cells, where glucose is indispensable for the generation of energy.

Diabetics suffer from Insulin deficiency, from impairment in its function or from increased tissue resistance to Insulin and thus, when blood sugar levels increase, an adequate response of Insulin release is absent.

As a result, glucose accumulates in blood. This condition is called Hyperglycemia.

When glucose level surpasses a certain threshold, it is also excreted in urine. This condition is called Glycosuria.

The symptoms resulting from elevated glucose levels are increased secretion of urine, thirst and weight loss.

There are two main types of Diabetes: Type 1 (IDDM, Insulin dependent Diabetes Mellitus) and type 2 (NIDDM, non-Insulin dependent Diabetes Mellitus).

Type 1 Diabetes, also known as youth onset Diabetes, is usually manifested in childhood, its cause is Insulin deficiency resulting from destruction of the pancreatic cells responsible for Insulin secretion. Therapy consists of obligatory external Insulin supply.

Type 2 Diabetes, also called adult onset Diabetes, develops in adults, usually after age 40, is more frequent in females and its incidence increases markedly in obesity. It has a strong hereditary component. Its primary cause is low reactivity or increased resistance of the tissues to Insulin.

This condition of high Insulin resistance is closely related to the condition named “Metabolic Syndrome” or “Syndrome X”.

This syndrome includes central obesity (in the abdominal area and around organs), Hypertension, disturbed blood lipid levels, cardiovascular diseases, tendency to hyper-coagulation and more.

Treatment includes changes in life style: physical activity, appropriate diet, weight reduction and orally administered drugs. Sometimes, also Insulin treatment is necessary.

High blood sugar levels increase the risk for the development of vascular damage such as Atherosclerosis, and therefore Diabetes is a major risk factor of Ischemic heart disease.

Vascular damage in diabetes patients is not limited to only cardiac vessels, but can also include multi-system damage involving kidneys, lower extremities, brain, heart and eyes.

An additional damage that afflicts diabetic patients is neural damage.

The combination of peripheral nerve damage resulting in altered sensitivity to pain with increased tendency to Atherosclerosis may make the treatment of diabetic patients more difficult and deteriorate their condition.

For example, due to Coronary artery damage, the diabetic patient is exposed to a higher risk of heart attack on the one hand, while the nerve lesion with altered sensitivity may affect the manifestation of the attack and interfere with early diagnosis, on the other hand.

 

 

 

 



Diastole

The relaxation phase of the heart muscle.

This phase takes place between two contractions and during it the heart is being filled with blood.



Dyspnea (shortness of breath, breathlessness)

Breathing difficulty. Can be the result of many different conditions, including: heart diseases (heart failure), lung diseases (Chronic Bronchitis, Asthma, Emphysema and more) upper respiratory tract disorders (occlusion by a foreign body), metabolic problems and sometimes also mental disorders.



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e

ECG, Electrocardiogram

Recording of the electrical activity of the heart. The heart is a pump activated by electrical power. These electrical potentials can be recorded by ECG. The standard ECG is recorded from 12 different points. These reference points are created by placing electrodes on the body surface surrounding the heart. The points are exactly defined and each electrode records the electrical progress from its point of view. The electrodes are commonly called leads. The standard ECG is a 12-lead ECG. ECG recording can detect various heart problems such as rhythm disturbances or signs of a heart attack. .



Echocardiography

A technique, which uses sound waves (ultrasound) for the imaging of the cardiac anatomy and information regarding wall thickness, size of the cardiac chambers and the function of valves. Sometimes echocardiography is combined with stress test. Echo stress test provides information about the state of the coronary arteries as well.



Edema

Accumulation of fluids in any tissue due to leakage of fluid from a blood vessel into the extracellular space.



Electrical conduction system

A system originating from the natural pacemaker (Sinus) and ending in cells in the ventricles.

This system is capable of rapid transfer of electrical stimuli.

Its composition and structure assure that electric stimuli are transferred in a fully synchronized manner, i.e. each electrical pulse emerging from the Sinus reaches the cells in the ventricles at exactly the same time, which enables effective and powerful contraction.

With age, the conduction systems may be subject to different degenerative processes that in some cases necessitate the implantation of an artificial pacemaker.



Embolus

A particle that wanders with the blood stream from the site where it is created to another remote site, where it can cause arterial occlusion. Embolus can consist of thrombus (blood clot), air, fat and more.



Endocarditis

An inflammation process involving the Endocardium. Such inflammation is usually caused by Rheumatoid arthritis or by bacterial infection. The presenting symptoms are fever and variable heart murmurs. Complications, such as congestive heart failure of embolism are possible



Endocardium

Endocardium A delicate membrane covering the inner heart wall and the valves. Folds of this membrane form the cardiac valves.



Epicardium

The external layer wrapping the heart.



Ergometric stress testing

This test is designated for the identification or exclusion of Ischemic heart disease. In the course of the examination, the patient is submitted to physical exercise (ergometer bicycle or walking on a treadmill) in order to increase the pulse rate. As the pulse rate rises, ECG is recorded aiming at detecting ECG changes that may occur as evidence of cardiac distress caused by relative oxygen deficit.



External cardiac massage

A rescue action, which is part of the resuscitation procedure. The massage is performed by serial exertion of pressure and relaxation on the chest bone, at the rate of about 100 per minute. The massage is kind of external squeezing of the heart causing its voiding and filling to a certain extent and thus preserving cardiac output and blood flow to vital body organs for the duration of the resuscitation.

The quality of cardiac massage and the proficiency of the person performing it are considered as having major importance on the success of the resuscitation procedure.



Extra systole, premature beat

Normally, any electrical pulse engaging the heart muscle during each heart beat begins in the tissue called Sinus (SA node). This tissue has autonomic potential of generating such pulses.

This tissue is also known as natural pacemaker.

In some instances, for various reasons, electrical stimulation can be elicited from other sites in the heart, outside the Sinus, by cells that are under normal conditions not electrically active.

Usually, such impulse will be generated before the normal next impulse from the natural pacemaker, the Sinus, and it is therefore called “premature beat”.

Another name for such premature beats is Extra-Systole.

Premature beats can be generated from a supra-ventricular source (from sites located above the ventricles) or from sites located in the ventricles.

In many instances, the reason for the generation of such premature beats is unknown. They are more frequent under the influence of substances such as caffeine, nicotine or alcohol. They can be also associated with cardiac diseases.

Sometimes such premature beats can give a sensation of irregular pulse or of interruptions in the normal heart action.

Most extra systoles do not require medical treatment. The decision about initiating medical treatment for the suppression of premature beats will depend on the subjective feeling of the patient as well as on the cause for their appearance.



Extrasystole, premature beat

See under Premature beat.



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f

Familial hypercholesterolemia

A genetic defect causing elevation of blood cholesterol and lipid levels.



Flutter

A kind of rapid rhythm disorder causing the contraction of the afflicted part of the heart to be ineffective.

When such rapid rhythm affects the atria, it is called atrial flutter. Its consequences are similar to those of Atrial Fibrillation.

However, if this is found in the ventricles, ventricular flutter is an emergency situation requiring immediate life saving intervention. Without treatment this condition deteriorates to Ventricular Fibrillation and cardiac arrest.



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Heart (cardia)

A muscular organ comprising 4 chambers, located in the center of the chest, between the two lungs, with the apex pointing downwards and to the left.

It is divided by an impermeable septum into two parts, the left and the right heart, .

It is also divided into two compartments (upper and lower) called atria (vestibules) and ventricles.

A one-way valve separates each ventricle from its corresponding atrium.

The heart functions as a pump, which propels blood into the vessels of the body. The right heart pumps oxygen-depleted blood returning from the body organs into the lungs, while the left heart’s function is propelling oxygen-enriched blood coming from the lungs into all body organs.

This process is accomplished in the following manner: Oxygen-depleted blood is drained from the organs by the venous system and reaches the right atrium. From there it flows to the right ventricle and when the ventricle contracts it is propelled into the Pulmonary artery.

In the lungs, gas exchange takes place and blood is oxygenated.

The oxygen- enriched blood is transported by the Pulmonary veins to the left ventricle and by the contraction of the latter it is pumped directly into the Aorta, which by means of its many branches supplies oxygen rich blood to all organs of the body.

The synchronized activity of the different heart chambers is possible thanks to the electrical conductive system, which signals and stimulates the contraction and relaxation of the heart muscle.



Heart attack

 see entry Myocardial infarction.  



Heart murmur

An abnormal sound perceived while auscultation (listening to) the heart. This sound is produced by any disturbance in blood flow, for example when blood flows through a narrow opening or when flow turbulences exist. Conditions causing such disturbances are usually associated with valvular defects or defects in the septum dividing the two cardiac parts, the left and the right part. Sometimes, particularly in children, murmurs can be heard even if no anatomical defects are present. Murmurs are divided in systolic and diastolic murmurs, according to the phase of the heart action during which it is auscultated, the systole or the diastole, respectively.



Heart muscle

See entry: Heart



Heart rate (pulse rate)

See under: Pulse.



Heart scan

A method for the assessment of cardiac anatomy and physiology as well as of its Coronary arteries. It is based on injecting a radioactive substance and examining its distribution in the various segments of the heart walls.

In the course of this test, radioactive substances are used (mainly thallium 201 or technetium 99). These substances are characterized by their ability to reach such areas in the myocardium that are supplied with blood and include viable muscle cells.

A computerized gamma camera rotates around the patient and registers heart images from different perspectives.

Scanning of the heart (also called Scintigraphy) can be performed at rest and in stress situations.



Heart-lung machine

In most cardiac surgical procedures temporary interruption of the contractile activity of the heart is required in order to enable the surgeon the performance of the desired repair of the existing damage.

In such situations, blood must be stored in an external machine that practically mimics the heart and lung action.

Such machines include a pump and an oxygenation system. Blood is sent to the machine by tubing inserted to the veins draining oxygen-depleted blood into the right heart. After oxygenation, blood is returned under pressure to a great artery.



Heartbeat

See under Pulse.



Herz-Bypass-Operation

Mit einer Bypass-Operation wird für ein verengtes Blutgefäß am Herzen eine Umleitung gelegt (Bypass: engl. für Umleitung). Meistens werden dafür Venen aus den Beinen oder die inneren Brustarterien verwendet. Bei einer Bypassoperation ist der Einsatz einer Herz-Lungen-Maschine meist notwendig. Minimal invasiv werden zunehmend Bypässe am Herzen auch ohne Herz-Lungen-Maschine operiert. Bypässe mit Arterien sind widerstandsfähig und das Risiko für kurzfristig auftretende Re-Stenosen, als neue Verengungen, ist niedriger als bei Bypässen mit Venen.



Holter monitoring

An examination for identifying and documenting heart rate disorders. The patient is connected to a portable device, which continuously records the electrical activity of the heart for a 24-hour period.

After the examination is completed the result is analyzed in order to identify and diagnose the rhythm disorder.

Among the advantages of this test the fact must be mentioned that the examination is made during 24 hours and does not depend on the feelings and reactions of the person tested, whereby rhythm disorders that are difficult to identify can be evaluated, including such that the patient is not aware of their existence or such occurring during sleep or appearing for a very short time and therefore difficult to distinguish.

Among the disadvantages is the fact that an episode that did not occur during the particular 24-hour period of measurement cannot be documented.



Homocystein

Homocystein is an amino acid and its high level in blood increases the risk of the development of Atherosclerosis and thereby the risk of cardiac disease and heart attack.

The main reason for increased Homocystein levels in blood is folic acid deficiency and deficiency of vitamins of the B group. Consuming fruit and vegetables as well as supplementation of these vitamins helps in decreasing homocystein levels in blood.



Hypercholesterolemia

Greater than normal Cholesterol levels in blood. The tendency of developing high Cholesterol levels is effected by genetic factors, nutrition, age, body weight and others.

High Cholesterol level is one of the risk factors for the development of Ischemic heart disease.



Hyperlipidemia

Higher than normal blood fat (lipid) levels.



Hypertension

This is a very frequent disorder, characterized by blood pressure elevation on repeat measurements with values exceeding 140/90 mm Hg.

According to the recent guidelines of the Israeli Hypertension Association, blood pressure values below 120/80 mm Hg are defined as normal, values between 120-139/80-89 mm Hg require follow-up, because people with values in this range are at a double risk for developing Hypertension in the future.

Values between 140/90 and 159/99 mm Hg are defined as mild Hypertension and values above 180/110 mm Hg are defined as severe Hypertension.

Values between mild and severe constitute moderate Hypertension.
In the vast majority of cases, the causative factor is unknown.

In the minority of cases, an organic cause can be found, such as kidney problems, hormonal (endocrine) disorders and others.

In the medical literature, this disorder is called “silent killer”, because it is usually symptomless.

Therefore, it is very important to adopt a habit of measuring blood pressure periodically in order to detect the disease timely.

After the initial diagnosis is made, the treatment is established. The first step of the treatment is usually a change in life style leading to weight loss, physical activity and dietary adaptations.

If no response is present, a therapeutic attempt with drugs is performed.

There are many anti-hypertensive drugs with different action mechanisms.

In most cases, treatment is necessary for lifetime.

Treatment and balancing are very important, because this disorder is one of the most important risk factors for the development of Ischemic heart disease. 



Hypotension

Low blood pressure (less than 90/50).

Low blood pressure often does not reflect any medical problem, unless it is caused by another medical condition, for example myocardial infarction.

Sometimes, people with low blood pressure may suffer from weakness and even loss of consciousness when additional drop of blood pressure occurs, for instance during particularly hot weather. Abundant drinking can prevent these symptoms.

Low blood pressure does not constitute protection from future development of hypertension.



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Interventricular septum

The partition wall dividing the two ventricles. Normally, this wall is impermeable, so oxygen-rich blood in the left ventricle cannot mix with oxygen-depleted blood from the right ventricle.

In certain congenital heart defects, this septum can have an opening. The solution of the problem, if necessary, is a surgical correction.



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Lead

This term is associated with Electrocardiographic (ECG) recording.

The term “lead” relates to the point in space received in result of placing of electrodes in pre-defined points in the body around the heart.

The standard ECG includes 12 leads, i.e. 12 points in space that “look”, each one from its perspective, at the electrical activity of the heart. Each lead records the activity that it “observes”.

As a general rule, when a lead identifies electrical activity approaching it, a rising graph is recorded and when the activity is drawing away, a descending graph is drawn.

The knowledge of the location of the leads in space and of the pathways of the electrical activity flow in the heart helps to decipher the ECG and to identify pathology.



Left ventricle

The left ventricle is filled during the diastole from the left atrium with oxygen-rich blood. During systole the left ventricle empties directly to the Aorta and from there, by means of its many branches, it reaches all arteries of the body. Thus different body organs can regularly be nourished with oxygenated blood.

The left ventricle has a stronger and thicker wall than the right one and works against greater pressure resistance; its oxygen consumption is greater and therefore it is more vulnerable in situations when oxygen supply is compromised, such as infarctions.



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Mitral regurgitation

Defective Mitral valve, which is located between the left atrium and the left ventricle of the heart. As a result of this defect in the valvular closure, leakage from the left ventricle to the left atrium is present during systole Symptoms may include breathing difficulties and rhythm disturbances. The treatment, depending on severity, is surgical.



Mitral stenosis

Narrowing of the Mitral valve located between the left atrium and the left ventricle. Resulting from this narrowing, impaired blood flow is encountered during the diastole from the atrium to the ventricle.

On cardiac auscultation, a diastolic murmur is perceived.

Symptoms are usually associated with blood congestion in the atrium (due to more difficult voiding) and they include shortness of breath as well as rhythm disturbances due to anatomical changes of the atrium and more.

If necessary, surgical treatment is applied: dilation of the narrowed valve or its replacement.



Mitral valve

The Mitral valve is located between the left atrium and the left ventricle.

Its task is enabling blood flow from the atrium into the ventricle during the contraction of the atria, but it also must prevent back flow into the atrium during the ventricular systole, when the ventricular pressure mounts markedly.

Insufficiency of the mitral valve causes back flow to the atrium, thereby excess load for the atrium and even blood return to the lungs.



Mitral valve prolapse (MVP, Barlow’s syndrome)

An anatomical defect of the Mitral valve, causing prolapse of one of the valvular leaflets towards the atrium during closure.

It is a frequent disorder, with increased frequency of appearance in women at age 20 to 40, with a hereditary component.

Most often, the structural defect is unnoticed and is detected incidentally, but sometimes it can cause leakage during valvular closure (Mitral regurgitation).



MUGA (Multiple Gated Acquisition Scan)

A method for the evaluation of cardiac anatomy and physiology by injecting a radioactive substance, Technetium 99.

One of the most important indices that can be obtained from this examination is the value called ejection fraction (EF).

Ejection fraction is the percent of what enters the left ventricle and what leaves it during each heart beat. In a healthy heart, ejection fraction is about 55% or more. This means that 55% of the blood content included in the left ventricle at the peak of its filling phase (end diastolic) is expelled from it at the peak of the contraction (end systolic).

The lower the EF values the more severe is the functional impairment of the heart.
The examination can be performed at rest or during effort in order to evaluate changes in cardiac output under stress conditions.



Myocardial infarction

This process is called in popular language “heart attack”. Myocardial infarction is caused by occlusion of an artery responsible for blood and oxygen supply to a given area of the heart. Such occlusion usually occurs by a joint action of a lipid plaque (atherosclerosis, sclerosis) and an overlying blood clot (thrombus). As a result of such occlusion, the vital oxygen supply is cut-off from this area and the involved cells undergo a process of necrosis, during which a proportion of cells are irreversibly damaged and die.



Myocardial ischemia

Ischemia is a condition, in which there is discrepancy between oxygen requirement at a given time and the amount of oxygen supplied to the heart. Such discrepancy is usually due to a partial narrowing of an artery caused in most cases by the formation of a lipid plaque in the arterial wall. Narrowing of an artery (stenosis) limits the blood amount flowing through it, with reduced amount of oxygen supplied to the area by such a vessel. Because the oxygen requirement of the heart grows with increased body activity, situations that increase the activity of the heart, such as exercise or mental stress may induce this discrepancy between oxygen demand and supply and thus induce ischemia.



Myocarditis

An inflammatory disease inflicting the heart muscle.

It can be a reaction to viral or other infection, exposure to some substances or an inflammatory process called “auto-immune”, in which different mechanisms can induce an inflammatory process without involvement of infectious agents.

The disease can have different manifestations in different individuals. It can vary from complete lack of symptoms, through mild flu-like symptoms accompanied by chest pain and shortness of breath and up to heart failure or a lethal rhythm disorder.



Myocardium

Heart muscle



Myoglobin

A pigmented material contained in muscle cells, which serves as oxygen reservoir of the muscular fiber.

Increased level of Myoglobin in blood may indicate damage to the Myocardium (heart muscle), as encountered in a heart attack and thus be helpful in the diagnosis of myocardial infarction.

However, it must be stated that increased Myoglobin level in blood is an unspecific finding and can occur in various conditions, other than Myocardial Infarction, because any muscular damage can increase its blood level.



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Natural cardiac pacemaker

See entry: Sinus 



Normal sinus rhythm (NSR)

Heart rate originating from the Sinus (natural pacemaker) activity, i.e. resulting from an electrical stimulus generated in the Sinus and propagated normally by the electrical conduction system of the heart.

Sinus rhythm is defined as normal if the rate is between 60 and 100 per minute.

This rhythm can be above or below the limits of range in certain physiological situations, for instance during exercise or during sleep, respectively, but also as a reaction to pathological situation.



Nuclear cardiology

Research and diagnosis of cardiac diseases by means of intravenous injection of radioactive substances enabling cardiac imaging by a computer-controlled gamma camera.

In cardiology, this method serves for Thalium scanning and provides information about Coronary arteries and for MUGA scanning, by which cardiac function can be determined.



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Obesity

Overweight due to fat accumulation in the body.

The principal indicator of obesity is the body mass index (BMI).

BMI is calculated by dividing the body weight in kilograms by the square of height in meters (BMI = kg/m2).

The accepted definitions of fat level according to BMI are:

BMI less than 18.5 – underweight

BMI between 18.5 – 24.9 – normal weight

BMI between 25.0 – 29.9 – mild overweight

BMI between 30.0 – 39.9 – substantial overweight

BMI more than 40.0 – severe/morbid obesity

An additional index evaluating the obesity status is the waist to hip ratio (WHR).

Many recent medical studies confirmed the association between obesity and the development of Hypertension, Diabetes, cardiac diseases and certain kinds of cancer.



Open Heart Surgery

A surgical intervention requiring temporary interruption of the heart action and connecting the patient to a heart-lung machine.



Operation for the correction /replacement of a valve

Several surgical options for the correction of damaged cardiac valves exist. Valvular replacement will be usually performed if the functional impairment of the Aortic or Mitral valve is severe.

There are two kinds of valvular prostheses:

1.Mechanical valves – made of materials such as plastic, carbon or metal. They are durable and resistant for extensive periods. Because blood tends to stick to these materials and create blood clots around them, people who underwent implantation of such valves must take anticoagulants for lifetime.

2.Biological valves – made of animal or human tissues. They are less resistant than mechanical valves, but do not require use of anticoagulants.

Usually, they must be replaced approximately every 10 years.



Orthopnea

Shortness of breath that worsens in supine position and improves in sitting position. This is a typical symptom in congestive heart failure. People suffering from this symptom sleep on a large number of pillows for raising the upper part of the body or sleep in sitting position.



Orthostatic hypotension

Blood pressure drop that occurs during a sudden change of position from supine to sitting or upright.

This is more frequent in patients treated with antihypertensive drugs.

Symptoms such as sudden weakness, dizziness, sensation of fainting and real syncope may occur.



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Palpitations

Awareness of heart beats.

This can be an unpleasant and an anxiety arising sensation.

The awareness of heart beats can be a normal phenomenon, for example in states of excitation, fear or exertion, in which the heart rate is accelerated.

Sometimes, the awareness of heart beat can be an evidence of a rhythm disorder, such as irregular, rapid or very slow heart beat.



Pericarditis

Inflammation of the Pericardium, the membrane enveloping the heart.

The inflammatory process can be a reaction to an infectious agent, such as virus, to toxic substances, or without the presence of an external infectious factor, a condition resulting from exaggerated activity of the immune system (auto-immune reaction).

Sometimes, Pericarditis can develop in early or late stages of recovery from Myocardial Infarction. It can be an acute or a chronic process.

Symptoms may include breathing difficulties, rhythm disturbances and fever.

Sometimes, as a result of the inflammatory process, fluid can accumulate between the Pericardium layers. This is called Pericardial Effusion. In some cases, chronic thickening of the firm, fibrous layer, can result. This can be an impediment for the relaxation of the heart and its filling with blood.

The treatment is according to the causative factor.



Pericardium

A memranaceous cover enveloping the heart. It consists of two parts: the outer, fibrous and more rigid envelope firmly connected to the large vessels coming out from the heart and the serous inner envelope.

The latter has two layers: the inner one, Epicardium (outer heart layer) is adjacent to the heart muscle and the outer one covers the fibrous part from inside.

A small amount of fluid is contained between these two layers, intended to prevent friction between the two surfaces during the excursions of the heart.



Physical Exercise, Exercising, Workout

Lack of permanent physical activity is now recognized as a risk factor for the development of Ischemic heart disease.

Aerobic exercise improves heart resilience (educating it to reach higher levels of effort with less pulse rate and work load), helps in weight reduction, more efficient lipid metabolism and can facilitate the creation of natural blood vessels bypassing stenoses (collateral arteries).

The recommended aerobic heart-protecting physical activity is walking, jogging, bicycle riding and more. In fact, during such activities, large muscle groups are continuously activated without interruptions. In order for aerobic physical activity to achieve its heart-protective goals, it is recommended to engage in such activities 3 to 5 times weekly for 30 to 50 minutes each time.



Post-myocardial infarction syndrome

An inflammatory syndrome, which can appear during the recovery phase after a myocardial infarction or following cardiac surgery.

It is characterized by an inflammatory process of the pericardium, which can be manifested by fever, chest pain, shortness of breath and more.



Pounding of the heart

See entry: Palpitations.



Pulmonary artery

Originates from the right ventricle of the heart and carries oxygen-depleted blood to the lungs.

This is indeed the only artery of the body carrying oxygen-depleted blood.



Pulmonary congestion

Congestion of the pulmonary vasculature due to pathologic accumulation of blood.

This condition can deteriorate to a dangerous clinical picture of Pulmonary edema.

The condition is usually caused by heart failure (cardiac insufficiency), although other causes, cardiac and non cardiac, also exist.



Pulmonary edema

Accumulation of fluid in the air spaces of the lungs, causing a sensation of breathing difficulty. If not treated, this can be an emergency situation with immediate life threat. The most common cause is cardiac insufficiency (congestive heart failure), but other causes, cardiac and extra-cardiac, may be also responsible.



Pulmonary embolism (PE)

Pulmonary embolism is a condition, in which a thrombus, air bubble, fat from a fractured bone or particles of other materials (such as lipid substances from an atherosclerotic plaque) reach by the way of blood circulation any pulmonary blood vessel and occlude it.

As a result, respiration turns less efficient. Air can enter the lungs freely, but oxygenation (enrichment of blood with oxygen) is impaired because of compromised blood flow.
This is an emergency situation requiring immediate diagnosis and treatment.

Symptoms may include: sudden shortness of breath, chest pain, rapid pulse rate, low blood pressure, cough (sometimes bloody cough) and more.

In some instances, pulmonary embolism can have no symptoms or only unspecific manifestations, which makes the proper diagnosis difficult.
The majority of pulmonary emboli stem from deep veins of the lower extremities.

Factors increasing the risk of deep vein thrombosis are: prolonged immobility (as, for example, during long distance flights), recent surgical procedures, malignant diseases, trauma of lower extremities, previous history of thrombosis in the lower extremities and congenital or acquired hypercoagulability states.



Pulmonary hypertension (PHT)

Normally, the pressure in the pulmonary vascular system is much lower than in the systemic circulation (the Aorta and all its branches).

Increased pulmonary pressure can result from various pulmonary diseases, acute or chronic, and can be a complication secondary to various valvular problems or other anatomical alterations of the heart.

Sometimes, pulmonary hypertension develops without any evident cause.

Usually, chronic pulmonary hypertension effects the right compartments of the heart and the end result is right heart failure.



Pulmonary stenosis

Narrowing of the Pulmonary valve. This may be often associated with other heart defects. The ensuing impairment is in blood flow from the right atrium into the Pulmonary artery during systole. A systolic murmur ensues.

Because there is impaired blood flow into the lungs, symptoms will usually be such of insufficient oxygenation of tissues, resulting in cyanosis, weakness, fainting etc. The solution of the problem is surgical correction.



Pulmonary valve

This valve is located between the right ventricle and the outlet of the Pulmonary artery.

It should stay widely open during the ventricular systole to enable voiding of the right ventricle into the Pulmonary artery.

During diastole, when pressure in the ventricle decreases, this valve must be closed to prevent back flow (regurgitation) of blood from the pulmonary artery in the direction of the ventricle.



Pulmonary vein

This vessel carries oxygenated (oxygen-rich) blood from the lungs to the left atrium of the heart.

This is the only and unique instance where oxygen-rich blood is carried by a vein (normally such blood in transported by arteries).



Pulmonic regurgitation

Abnormal blood flow through the Pulmonic valve during the diastole. The direction of leak is from the Pulmonary artery back to the right atrium during the diastole.



Pulse

The pulse that is measured reflects the number of heart beats per minute, or in other words – the heart rate. (Heart beat is defined as one systole and one diastole.)

The normal pulse rate of an adult person is between 60 – 100 per minute and tends to increase in states of exertion or excitement and to decrease at rest or during sleep.

The pulse can be felt due to contraction and widening of an artery palpated following filling or emptying of blood through the action of the heart.

The pulse can be felt in the Radial artery (in the wrist), in the Femoral artery (in the inguinal region), in the Carotid artery (in the neck) as well as in other locations of the body.



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Rheumatic Heart Disease

Damage to cardiac valves or to myocardium caused by exposure to Rheumatic fever.

Rheumatic fever is a disease inflicting mainly children and young adults and is a late complication of upper respiratory tract infection by the microorganism Streptococcus Pyogenes. The main characteristics are fever, arthritis and a specific rash on the face.

Symptoms that can evidence to cardiac involvement may occur, among others Myocarditis (inflammatory disease of the heart muscle, Endocarditis (inflammatory disease of the inner layer of the heart and the valves) or Pericarditis (inflammatory disease of the outer heart cover)



Rhythm disturbances

 see Arrhythmia



Right ventricle

The right ventricle is filled with blood during diastole from the right atrium. This blood has low oxygen content.

During systole the right ventricle empties into the Pulmonary artery, which carries blood to the lungs, where oxygenation takes place.



Risk factors

A certain medical condition, a certain style of life or a certain environmental threat that enhances a person’s risk to acquire a disease. Risk enhancement is a term referring to statistical likelihood and does not deal with a causative relation.



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Semilunar valve

This is the name of the valves located at the outlet of the great vessels: the Aorta and the Pulmonary artery.



Septal defect

A congenital malformation, in which the partition wall between the heart chambers is not perfect and blood passage through the septum is possible.

The defect can be located in the septum separating the upper compartments of the heart (atrial septal defect, ASD) or in the septum dividing the ventricles (ventricular septal defect, VSD).

The presence of such defect results in leakage of blood, predominantly from the left side, where pressure is higher, to the right. The right side will have to cope with greater load and this can result in Pulmonary Hypertension with subsequent cardiac insufficiency. If necessary, such defects can be surgically repaired.



Shock

A dangerous drop of blood pressure with symptoms of insufficient blood flow to different body organs. Clinical symptoms include: pallor, profuse sweating, cold and moist skin, rapid and weak pulse, irregular respiration, reduced urine output, altered consciousness state and even death.

Causes of shock may include: severe damage to the pump function of the heart (Cardiogenic shock), massive loss of fluids (Hypovolemic shock) due to massive bleeding or desiccation, severe allergic reactions (Anaphylactic shock), severe infections (Septic shock) and severe damage to the nervous system (Neurogenic shock).

 



Sick sinus syndrome (SSS)

This syndrome is characteristic for old age and is caused by degenerative processes of the electrical conduction system of the heart. The degenerated conduction system tends to give rise to different rhythm disorders, which can be rapid or slow. Therefore, it is also known in the literature as “rapid-slow syndrome”.

Patients suffering from this disorder may experience weakness, syncope, chest pain or dyspnea resulting from the alternate slow or rapid heart rate.

Quite often, this syndrome may pose a serious therapeutic challenge, because rapid heart rate disorders require drugs that slow up the heart rate, but such slowing can be too drastic because of the tendency to slow heart rate. Therefore, such patients often need pacemaker implantation to protect them from too slow rhythm and thus enabling proper medical treatment against rapid rhythm disorders.



Sinus bradycardia

Heart rhythm originating from the normal Sinus tissue, but slower than normal (less than 60 beats per minute).

In certain situations, such rhythm can be a normal, physiologic phenomenon, for example during sleep or in athletes. Sometimes, slow rhythm can signify a problem, for example a side effect of a drug, hypothyroidism, certain types of heart attacks and more.



Sinus tachycardia

Heart rhythm originating from the normal Sinus tissue, but more rapid than normal (more than 100 beats per minute).

Sinus tachycardia can be a physiological response to certain situations, such as exertion, excitement or pregnancy. Sometimes it can indicate a medical problem, such as side effect of a drug, fever, exsiccation, bleeding, anemia, hyperthyroidism and more.



Sinus, SA node

Tissue composed of cells with potential of autonomous generation of electrical impulses. It is located in the right atrium.

Electrical impulses are generated in the Sinus and they are propagated throughout the heart by means of an electrical conduction system. In such way impulses generated in the Sinus reach the cardiac ventricles synchronically, thereby assuring their homogenous, synchronous and powerful contraction.



Situs Inversus (right/hearted)

This is a condition, in which the heart is located in the right half of the chest, caused by a congenital malformation.

This can be associated with additional malformations.



Spasm of a coronary artery, Prinzmetal’s angina

An abnormal contraction of the smooth muscle of a Coronary artery.

Such contraction causes significant narrowing of the vessel and reduced blood flow that can pass through this artery.

The reduction in blood flow and in oxygen supply may induce symptoms of Angina Pectoris and in some instances even cause Myocardial Infarction.

This condition tends to occur rather in young individuals and to appear at rest.

The treatment is usually medical by drugs preventing smooth muscle contraction.



Stenocardia

See entry: Angina pectoris



Stent

A device in the form of a spring for supporting tubular structures.

The common use of stents in cardiology is as a supplement to Angioplasty (ballooning) procedures. One of the principal problems of the ballooning procedure for dilating a Coronary artery was re-stenosis of the dilated segment after a relative short time.

The use of stents substantially reduced the rate of re-stenosis.

Recently, stents that act also by chemical methods by secreting a substance, which is capable of reducing cell replication (drug eluting stents), were developed. This can further reduce the rate of re-stenosis.



Stress test

see Ergometry



Supra-ventricular tachycardia (SVT)

A rapid rhythm disturbance originating from the upper heart regions (above the ventricles)

Generally, rhythm disorders originating from the upper heart regions are considered to have a lower risk potential compared with those originating from ventricles, although the risk estimation depends on the rapidity and the duration of the disorder and on the basic health or disease status of the heart that must cope with it.



Syncope (fainting)

Loss of consciousness for a short time caused by an acute transient drop of blood flow to the brain.

Causes can vary and include: standing for a long time, blood pressure drop due to drugs, very rapid or very slow heart rhythm disorders or certain emotional situations.

Usually, after falling or change to a supine position, the cerebral blood flow improves and recovery takes place.



Systole

The phase, during which the ventricles contract and propel blood included in them to the main blood vessels.

The left ventricle sends oxygen-rich blood to the Aorta, while the right ventricle forces oxygen-depleted blood to the Pulmonary artery.



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Tachycardia

Rapid heart rate, more than 100 beats per minute.

Accelerated heart rate can be a normal physiologic reaction of the body to physical strain or excitement. In these situations, the origin of the heart beats is from the natural and normal pacemaker, the Sinus node.

In some instances, the accelerated heart rate is due to a rapid rhythm disturbance and in these situations the rhythm originates from tissues outside the sinus located in other points of the heart.

The clinical manifestation and the therapeutic approach depend on the rapidity and the duration of the disorder, on the basic state of the heart as well as on the specific type of the disorder.



Tamponade

A condition, in which fluid (blood or other fluid) accumulates in the Pericardium, the space between the heart and the membrane enveloping it.

Such accumulation of fluid, if it is rapid and acute, exerts pressure on the heart, interferes with the contraction and relaxation process and can constitute an emergency.



Tetralogy of Fallot

A congenital heart disease, combining a number of heart defects: stenosis of the right ventricle outlet, incomplete closure of the inter-ventricular septum (the partition wall separating the left and the right ventricle), dilatation of the right ventricle and displaced Aorta.

The result of these defects is blood leak from the right ventricle to the left ventricle through a hole in the septum.

The significance of such leak is mixing of non-oxygenated blood from the right ventricle with oxygen-rich blood from the left ventricle.

As a result, the body tissues are supplied with “mixed” blood, i.e. with lower oxygen level than required and this is manifested by cyanosis.

The solution of the problem is surgical correction.



Thallium Heart Scan

A method for the assessment of blood flow in the Coronary arteries and diagnosing flow disturbances caused by stenosis (narrowing) of these arteries.

The examination is performed by injecting the radio-isotope Thallium 201 and following its absorption in various areas of the Myocardium.

Perfusion (blood flow) defects show as areas emitting less or no radioactive radiation and are visible as “cold spots” on computerized imaging making use of a gamma scanner.



Thrombolysis

Lysis means dissolution, liquefaction. Thrombus is a blood clot. Thus, thrombolysis means chemical dissolution of blood clots by drugs.

The best known drugs for this purpose are streptokinase and TPA.

These drugs are given intravenously in certain cases of myocardial infarction (heart attack) to dissolve the blood clot, which together with a lipid plaque in the arterial wall totally occlude it.

One of the undesired inherent side effects of these drugs is that they can cause bleeding. Therefore, there are strict indications for the administration of such drugs.



Thrombus (blood clot, clot)

A solid mass formed by blood clotting in a blood vessel or in the heart. Blood clots consist of a mesh of protein called fibrin, in which blood cells are captured.

The main risk of a thrombus is occluding a blood vessel and thereby reducing or interrupting blood flow in this vessel.

The negative influence of a thrombus may be manifested at the site where it was formed or at a remote site, where it arrives as embolus.

 

An example of a condition, in which thrombus causes local damage is Myocardial Infarction. Most Myocardial Infarctions occur through a mixed mechanism of thrombus occurring upon a lipid plaque (Atherosclerosis) which together can totally occlude an artery and prevent blood and oxygen supply to a part of the heart nourished by this particular artery.

An example of a thrombus that has an impact on a remote site is embolism. This is an event of a thrombus formed in the heart, which is expelled during ventricular systole to the Aorta and from there it reaches with the blood stream a remote organ, such as brain or kidney, where it causes an ischemic damage.

There are special medical conditions with increased tendency to embolism. Such are for instance rhythm disorders called Atrial Fibrillation or state after valve replacement. Blood clots formed in the heart may be sent from there as thromboembolism to different body organs and cause an ischemic damage to these organs.

Therefore, patients suffering from such conditions are often treated with drugs preventing blood coagulation (sometimes called blood thinners).



Transposition of the great vessels

A congenital heart defect.

The great vessels: the Aorta and the Pulmonary artery, originate reversely from opposite ventricles, i.e. the Aorta originates from the right ventricle instead from the left one, and the Pulmonary artery originates from the left ventricle instead from the right one.

This disorder is amenable to surgical treatment.



Tricuspid regurgitation

Abnormal systolic blood flow through the Tricuspid valve, which is located between the right ventricle and the right atrium. During the systole, the Tricuspid valve should be completely closed to enable the contracting right ventricle the voiding of its blood content only into the Pulmonary artery without being returned to the right atrium. The symptoms can include edema, general weakness, tiredness etc. The treatment, depending on severity, is surgical



Tricuspid stenosis

Narrowing of the valve located between the right atrium and the right ventricle. As a result of the stenosis, there is difficulty in voiding of the right atrium into the right ventricle during diastole. On cardiac auscultation, a diastolic murmur is perceived. Symptoms reflect overload of the right atrium.

The solution of the problem is surgery.



Tricuspid valve

The valve is located between the right atrium and the right ventricle.

Its task is enabling free blood flow from the right atrium to the right ventricle, but preventing back flow in the opposite direction during the ventricular systole, when the pressure in the ventricle mounts.



Trigeminy (trigeminal rhythm)

A rhythm disturbance with a repetitive pattern composed of two normal beats (originating from the sinus) followed by a premature beat originating from the ventricle or the atrium.



Triglyceride

A certain kind of lipid consisting of Glycerin bound to 3 fatty acid molecules.

High triglyceride levels indicate a tendency to increased incidence of heart diseases, especially in women.



Troponin

A protein substance, one of the cardiac markers or enzymes (as they were called earlier) assisting in the diagnosis of Myocardial Infarction.

As a general rule, enzymes are protein substances found normally in the Myocardium (heart muscle) cells.

When infarction occurs, i.e. when cells are destroyed, enzymes are released into the blood stream and their blood level increases. Therefore it is possible to use them as markers for the diagnosis of Myocardial Infarction.

Troponin levels begin to rise 6 hours after the start of infarction.

Its presence is a strong evidence of Myocardial Infarction and its blood level remains high for several weeks.



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Vagus nerve

The tenth cranial nerve. It is called “Vagus” (aberrant in Latin) due to its very long path in the body.

The Vagus nerve has many branches and it innervates many organs of the body, among others the Urinary tract, the Digestive system and the heart.

It effects the heart by slowing the heart rate.

The term “Vaso-Vagal episode” relates to over- activity of the Vagus.

Such activity can cause slowing down of the heart rate and decrease of blood pressure and as a consequence fainting. Such episodes can happen as a reaction to pain, mental stress, anxiety or stimulation of other organs that are innervated by the Vagus nerve, for example during urination or bowel movement.



Valve

A structure in a blood vessel enabling blood flow in only one direction. The valves are built of a kind of pockets, which are approximated to the wall and thus blood flow is enabled as long as pressure holds the “pockets” open.

But when blood flow is attempted in the opposite, undesired, direction, the “pockets” fill with blood, close the opening and preclude such flow.



Valve regurgitation

A condition occurring when the closure of a cardiac valve is disturbed. The function of the valves is preventing blood flow in undesired direction across a pressure gradient. When the closure is partial or incomplete, blood flow in undesired direction is enabled and this condition can cause symptoms or disease. The kind of symptoms depends on the location of the valve, on its function and on the severity of its functional disturbance.



Valve stenosis

A situation, in which the opening of a cardiac valve is not complete and thereby the passage of blood through it is impaired.

Blood flow through a narrowed valve is usually manifested by a murmur, which can be heard during the phase when blood is flowing through the valve.

Clinical symptoms depend on the severity grade of the stenosis.

Usually, the cardiac compartment that must push blood through the stenosed valve is overloaded with work and the increased burden can cause structural changes of the affected compartment.

In addition, symptoms of congestion and edema may be present because of incomplete voiding.

If necessary, surgical correction is performed.



Vein

A blood vessel that normally carries oxygen depleted blood. The flow direction in veins is from the various body organs towards the heart.



Vena Cava (“The empty vein”)

This large vein is composed of two parts: the inferior (lower) and superior (upper) Vena Cava. Both parts drain oxygen depleted blood from different parts of the body to the right atrium of the heart.



Ventricle

The lower heart chambers are called ventricles.

During diastole the ventricles are filled with blood emptying to them from the atria.

The right ventricle is filled from the right atrium, while blood flows through the Tricuspid valve.

The left ventricle is filled from the left atrium, while blood flows through the Mitral valve.

During the systole the ventricles pump the blood contained in them into the large vessels.

The right ventricle empties to the Pulmonary artery, from which blood is transferred to the lungs.

The left ventricle empties to the Aorta.



Ventricular fibrillation (VF)

A potentially life threatening rhythm disturbance. This disorder originates in the ventricles and is caused by very rapid and unsynchronized electrical activity, causing totally ineffective contraction. The result is a steep decline of cardiac output. This dramatic decline of effective cardiac output means less blood supply to the brain with subsequent loss of consciousness and respiratory arrest.

In fact, ventricular fibrillation is cessation of the most vital processes and without treatment death is the inevitable result. Treatment consists of basic resuscitation processes, including heart massage and artificial respiration.

In addition, defibrillation must be applied for stopping the rapid and chaotic ventricular rhythm by electrical shock.

The success chances of the resuscitation are directly dependent on the early onset of such procedures. Time is absolutely critical and the more time elapses between the onset of resuscitation actions and collapse, the less are the odds for success.

Ventricular fibrillation occurs mainly as a complication of Myocardial Infarction and it is the principal cause of demise prior to hospitalization in the myocardial infarction population of patients.



Ventricular tachycardia

A dangerous rapid rhythm disorder. It originates from the ventricles and outside the normal tissue of the Sinus.

The rate can reach very high levels, even more than 200.

Symptoms such as breathing difficulties, chest pain, dizziness and others are possible.

In most cases, treatment is mandatory. It can be treated by medications or by re-establishing the normal heart rate by electrical shock.



Vestibule

See under: Atrium



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Wolff-Parkinson-White Syndrome (WPW)

A congenital anatomical disorder, in which an additional electrical conduction pathway connects the atrium with the ventricle. This additional pathway is known as Kent’s bundle.

Due to this bypass, electrical stimuli arising from the sinus may reach the ventricle sooner than by the normal pathway; this is responsible for the other name coined for the condition: pre-excitation syndrome.

This anatomic variation exposes the patient to rapid rhythm disorders known as supraventricular tachycardia and atrial fibrillation. However, in many instances people with this anomaly are symptomless and the diagnosis is made incidentally by a specific pattern identified on ECG .

If necessary, surgical intervention can be performed (by cauterization of the superfluous bundle).



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