[Exertion-induced myocardial ischemia has little influence on ventricular remodeling in post-infarction patients with preserved systolic function]

Abstract

Background: The effects of acute and recurrent ischemia on ventricular function are well documented. However, the role of residual exertional ischemia in the remodelling process after infarction has not yet been established. In this study, we investigated whether exercise-induced myocardial ischemia influences left ventricular remodelling in patients with recent myocardial infarction and preserved left ventricular function and volumes.

Methods: Sixty-four patients with a first anterior Q wave myocardial infarction were studied at 5 weeks by rest echocardiography and exercise scintigraphy; the echocardiographic examination at rest was repeated 6 months later. Based on the presence and extent of reversible perfusion defects on exercise scintigraphy, patients were classified as having no exertional ischemia (group 1, n = 13 [20%]), mild to moderate ischemia (group 2, n = 32 [50%]) and severe exertional ischemia (group 3, n = 19 [30%]).

Results: At 5 weeks after infarction left ventricular volumes, ejection fraction, percent wall motion abnormalities and regional dilatation were similar in the three groups. After 6 months, end-diastolic and end-systolic volumes and regional dilatation did not change in patients in all groups, while ejection fraction and percent wall motion abnormalities showed a slight but significant (p < 0.01) improvement in all groups.

Conclusions: Exercise-induced myocardial ischemia, either mild or severe, does not affect ventricular remodelling and function after myocardial infarction in patients with preserved ejection fraction.