Exercise-induced cyclic episodes of S-T segment elevation in a patient with variant angina.

A unique case of variant angina is described in which cyclic S-T segment elevation was reproducibly induced by exercise. The treadmill test revealed cyclic S-T segment elevation to occur from the first minute onward, recurring with a cycle length of 2 min throughout the exercise while the work load was being increased. Similar cyclic episodes were also induced by the cold pressor test, and the ambulatory electrocardiogram demonstrated spontaneous episodes of S-T segment elevation with a similar cycle length in early mornings. Coronary arteriography revealed a fixed lesion in the mid-portion of right coronary artery with a 90% narrowing associated with coronary spasm leading to subtotal occlusion. The cyclic episodes were abolished by the administration of the calcium antagonist diltiazem. The spontaneous phasic activity of coronary arterial muscle is discussed as a possible cause or mechanism.