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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.
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.

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