Coronary arterial spasm as a cause of exercise-induced ST-segment elevation in patients with variant angina

Four patients with variant angina pectoris exhibited reproducible exercise-induced chest pain and ST-segment elevation. Coronary arterial spasm was documented with arteriography during exercise-induced ST-segment elevation (three patients) or after intravenous administration of ergonovine maleate (one patient). Our observations show that in patients with variant angina exercise can trigger coronary arterial spasm, thus inducing anginal pain and ST-segment elevation.

Noninvasive documentation of Prinzmetal's angina

A 57 year old women with substernal nonexertional chest pain and angiographically patent coronary arteries was evaluated with two dimensional echocardiography and myocardial perfusion scintigraphy after provocation of pain with methacholine. Simultaneous with the development of angina pectoris, the electrocardiogram demonstrated S-T segment elevation in leads II, III and aVF, followed by atrioventricular block. The echocardiogram revealed akinesia of the previously normally contracting left ventricular posterior wall during pain followed by hyperkinesia after the administration of nitroglycerin. Perfusion imaging suggested reversible inferior wall hypoperfusion. Thus, these studies provided noninvasive documentation of segmental left ventricular dysfunction and hypoperfusion during variant angina.

Similarities of ergonovine-induced and spontaneous attacks of variant angina

Ergonovine has been shown to provoke attacks of variant angina, but a question remains whether spontaneous and ergonovine-induced attacks of variant angina are similar. Seven patients with variant angina undergoing cardiac catheterization were studied during transient episodes of spontaneous and ergonovine-induced rest angina with ST-segment elevation. Clinical, electrocardiographic, left ventricular hemodynamic and coronary angiographic observations were made before and repeated after ergonovine (0.05-0.2 mg I.V.). The character and duration of chest pain were similar during both spontaneous and ergonovine-induced episodes. ST-segment elevation (greater than 1 mm) was present inferiorly in three patients, anteriorly in three patients, and both inferiorly and anteriorly in one patient during both episodes. Mean heart rate and systolic arterial pressure changed little, while left ventricular end-diastolic pressure increased significantly during spontaneous or ergonovine-induced attacks. We observed subtotal or total dynamic obstruction in the left anterior descending (three patients), right coronary arteries (three patients) and both arteries in one patient during both attacks. Thus, in selected patients ergonovine-induced attacks of variant angina were remarkably similar to spontaneous episodes.

[Detection of coronary artery spasm by the methylergometrin test. Technic. Results. Indications]

Methylergometrine (Methergin) was given intravenously (0.4 mg) to 118 patients undergoing coronary arteriography. The electrocardiogramme and intraaortic pressure was continuously monitored whilst coronary arteriography was performed, 1,3, and 5 minutes after the injection of the ergot alkaloid. The test was positive if: 1) coronary spasm was observed; 2) if ST segment elevation was recorded with or without pain. Positive tests were obtained in 13 out of 14 patients with Prinzmetal angina. The test was negative in the other patients. However in 3 patients with Prinzmetal angina, the test produced typical coronary spasm without electrocardiographic changes. In Prinzmetal angina the sensitivity of this test was 93 p. 100 with a high specificity: 96-100 p. 100 depending on whether or not electrocardiographical changes associated with spasm are considered. Taking into account current therapeutic methods of treating Prinzmetal angina the indications of this test of coronary spasm are: 1) patients presenting with resting angina whatever the state of their coronary arteries; 2) patients with documented Prinzmetal angina with "angiographically normal" coronary arteries.

Variant forms of angina pectoris

3 patients with different clinical and electrocardiographic manifestations of coronary artery spasm are discussed. All 3 patients had anginal attacks at rest. In addition, 2 of these patients, who did not have significant preexisting narrowing of their coronary arteries, also had anginal pain related to exercise. During pain, 1 patient showed ST-segment elevation, the other ST-segment depression, while the third showed ST-segment depression shortly followed by ST-elevation on the electrocardiogram. At coronary angiography, spontaneous or induced spasm of one of the major coronary arteries could be demonstrated in all 3 patients. In 2 cases, sublingual nitroglycerin failed to completely relieve the spasm. This raises the question whether a residual stenosis after NTG conclusively proves a fixed organic narrowing. It is concluded that the clinical spectrum of spasm of the coronary arteries is wider than was originally reported by Prinzmetal and coworkers. Clinical and electrocardiographic manifestations are probably dependent on the site and severity of the spasm, which may cause different degrees of myocardial ischemia.