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.