Left ventricular ejection fraction during exercise in the patients with myocardial infarction : An index for cardiac reserve, (1)

To elucidate the factors affecting left ventricular ejection fraction (LVEF) during exercise (EX), bicycle ergometer EX tests was performed in 47 patients with old myocardial infarction (MI) using RI angiocardiography. Multiple regression analysis was performed to determine the important variables related to the change of LVEF during EX based on 12 variables; left ventricular end-diastolic volume (LVEDV), LVEF, heart rate (HR), systolic blood pressure (BPS) and BPS/left ventricular end-systolic volume (BPS/LVESV) at rest, % ΔLVEDV, % ΔHR, and % ΔBPS/LVESV during EX, age, sex and site of MI. The change of LVEF during EX was positively related to % ΔBPS/LVESV and % ΔLVEDV during EX (P<0.01). ΔLVEF had a good correlation with % ΔBPS/LVESV (r=0.53, P<0.01) which reflects cardiac contractility, while ΔLVEF had no significant relation with % ΔLVEDV which reflects preload. There was a significant and negative relation between % ΔBPS/LVESV and % ΔLVEDF (r=-0.64, P<0.01). Therefore, it is important to assess the change of BPS/LVESV as well as LVEF for evaluating cardiac performance in the patients with old MI. (author)