Severe spontaneous three-vessel coronary artery spasm.

Coronary artery spasm is usually defined as a focal constriction of a coronary artery segment, reversible, and causing myocardial ischaemia by coronary blood flow restriction. Sometimes this condition is not focal and can compromise all the coronary tree. This is a very rarely described event. Generally, coronary vasospasm may occur spontaneously or induced, either physically by catheter, physiological manoeuvres (hyperventilation), or by pharmacological agents. It may also occur with or without underlying atheromatous coronary disease. The mechanism of coronary spasm remains unclear but endothelial dysfunction seems to be the main triggering factor in all causes.