Twelve patients with exercise-induced ST-segment elevation without prior myocardial infarction, electrocardiographic evidence of left ventricular hypertrophy or left bundle branch block underwent thallium-201 tomography immediately after exercise and 4 hours later. Coronary angiography and left ventriculography were performed within an average of 8 days of exercise testing. Five patients had repeat exercise thallium-201 tomography after medical therapy or revascularization. All patients had large, reversible perfusion defects (average defect size 33.5 ± 13%), with 11 of 12 patients having a ≥25% stress perfusion defect. In 10 patients with atherosclerotic coronary artery disease, the average stenosis of the involved vessel was 93 ± 9% (range 70 to 100). The electrocardiographic leads with ST-segment elevation predicted the site of reversible hypoperfusion. Two patients had extensive, reversible anterior hypopeifusion due to exercise-induced spasm of minimally stenosed left anterior descending coronary arteries. Follow-up exercise testing in 5 patients showed abolition of reversible hypoperfusion and ST changes after medical therapy or revascularization. In patients without prior myocardial infarction, exercise-induced ST-segment elevation signifies extensive, reversible hypoperfusion that can be abolished by revascularization in patients with critical coronary stenoses and by medical therapy in those with coronary vasospasm.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine