The commonest cause of abnormal contraction of heart muscle is obstruction of the blood supply to that muscle as a consequence of the development of atheromatous plaques in the coronary arteries. Coronary heart disease can manifest itself as many welldescribed clinical syndromes, such as angina and myocardial infarction. The word stunning has come to refer to the reduced contraction of heart muscle which follows a period of restriction of blood flow and which occurs in the presence of the restoration of a normal blood flow. This entity may form part of the clinical syndromes of angina, unstable angina, and following cardiac surgery. Understanding the mechanisms may lead to more appropriate and even novel treatments for these conditions...