VENTRICULAR-FUNCTION AT REST AND DURING E XERCISE IN PATIENTS WITH LEFT-VENTRICULAR ANEURYSM

In 27 patients with anterior wall aneurysm after myocardial infarction (11 patients with 1-vessel disease, 16 with multi-vessel disease) lef t ventricular (LV) function was examined at rest and during exercise ( bicycle ergometer). No changes of LV volumes and ejection fraction (EF ) were observed, whereas the EF of the contractile part of the LV decr eased significantly. Mean pulmonary pressure as a measure of LV fillin g pressure increased. also did cardiac index due to the increase in he art rate. The patients were divided in two groups concerning the chang es of the EF during exercise: group EF(s) with an increase or no chang e and group EF(a) with a decrease. In EF(s) enddiastolic volume increa sed, whereas endsystolic volume did not change. In EF(a) enddiastolic volume did not change, but endsystolic volume increased significantly. In EF(s) the increase in cardiac index is caused not only by heart ra te. but also by the increase in stroke volume. An index of LV diastoli c compliance diminished in both groups during exercise. In patients wi th 1-vessel disease enddiastolic volume increased, endsystolic volume and EF did not change. In the other patients mean enddiastolic and end systolic volume did not change and EF revealed a small, but significan t decrease. These results show that in patients with LV aneurysm the i ncrease in EF during exercise is caused by an increase in preload. The increase in LV filling pressure in patients with increasing EF is due to an increase both in preload and diastolic compliance. In patients with impaired LV function (decrease in EF) the decrease in LV complian ce is the main effect of the increase in filling pressure during exerc ise.