Coronary artery spasm is a type of angina. Angina is pain that is caused by the heart muscles not getting enough blood. A sudden spasm or narrowing of a blood vessel that supplies the heart causes angina by reducing the amount of oxygen the heart receives. Coronary artery spasms often cause pain. Sometimes severe spasms can lead to irregular heartbeats. They can even cause heart attack, also known as acute myocardial infarction (AMI), and sudden death.
