LEFT-VENTRICULAR FILLING SHORTLY AFTER AN UNCOMPLICATED MYOCARDIAL-INFARCTION AS A PREDICTOR OF SUBSEQUENT EXERCISE CAPACITY

Resting measurements of left ventricular systolic function do not reliably predict exercise capacity in patients with cardiac disease. Therefore left ventricular filling shortly after a myocardial infarction was prospectively studied to determine whether it could predict subsequent exercise time. Consecutive patients with an acute infarction underwent Doppler and two-dimensional echocardiography within 36 hours of infarction. The study group was composed of the 26 men who did not have reperfusion, who had an uncomplicated myocardial infarction, and who had undergone symptom-limited stress testing during recovery (modified Bruce protocol, 44±23 days after myocardial infarction). Systolic function was measured by ejection fraction and a wall motion score. Ventricular filling was assessed by the peak transmitral Doppler velocity in early diastole (E), with atrial systole (A), their ratio (A/E), and the percentage of filling from atrial systole. The only parameter of systolic or diastolic function that correlated with exercise time was E (r=0.65, p<0.001). This relationship was particularly strong for the 16 subjects taking beta blockers at the time of stress testing (r=0.88, p<0.001). Stepwise multivariate regression analysis showed that only E and beta blocker therapy at the time of stress testing contributed to the model predicting recovery exercise time (R2=0.55). In summary, E, measured soon after an uncomplicated myocardial infarction, is one factor that predicts exercise capacity during recovery. © 1990 Mosby-Year Book, Inc.