Coronary Vasospasm in Ischemic Heart Disease

¹ From the Cardiovascular Research Unit, Royal Postgraduate Medical School, Hammersmith Hospital, London, England

A series of objective documentations indicate the need to reconsider the traditional concept that angina can result only from increased myocardial metabolic demand in the presence of coronary obstruction. A sudden decrease in blood supply may cause transmural or subendocardial ischemia resulting in transient elevation or depression of the ST segment on the ECG. Coronary vasospasm is at present the only convincingly demonstrated cause of reduction of blood supply and it appears to be a common cause of spontaneous angina at rest which occurs in patients with extremely variable degrees of coronary atherosclerosis and is characterized by elevation or depression of the ST segment. Other causes of reduction of coronary blood supply, such as platelet aggregation, may also play a role, but so far they could not be demonstrated in man. A provisional pathogenetic classification of angina may be useful for the management of anginal patients: (1) secondary angina, caused by an increase in myocardial demand above the fixed supply that has been limited by coronary atherosclerotic lesions (for which the approach is well-established); (2) primary angina, caused by other coronary or myocardial mechanisms that obviously require different diagnostic and therapeutic approaches. As was the case with hypertension, the classification may become more specific as the causes of primary angina are discovered. In several patients, angina caused by vasospasm coexists with typical secondary angina.