[Effects of percutaneous transluminal coronary angioplasty on left ventricular function at rest and during exercise].

The effects of percutaneous transluminal coronary angioplasty (PTCA) on left ventricular function at rest and during stress test were examined. Effect of PTCA at rest We studied 10 patients who fulfilled the following criteria, 1) single vessel disease, 2) high grade stenosis in the left anterior descending artery, 3) successful PTCA, 4) no restenosis, 5) without electrocardiographic evidence of previous myocardial infarction, and 6) technically adequate left ventriculograms in both pre and post PTCA studies. Follow-up studies were done six months after PTCA. Filling fraction as an index of early diastolic function was significantly lower than that of normal controls. There were no significant changes in left ventricular end-diastolic pressure, peak dp/dt, negative peak dp/dt, ejection fraction, left ventricular systolic pressure/end-systolic volume, between pre- and post-PTCA studies. Filling fraction in a jeopardized area, which was supplied by the left anterior descending artery, increased significantly after PTCA. No significant change was observed in the inferior area. Effect of PTCA during stress test A contrast stress test in eight successful cases without restenosis was performed by injecting 0.7 ml per kilogram of contrast material (76% urografin) at a rate of 13 ml/sec into the left ventricle before and six months after PTCA. The left ventricular end-diastolic pressure increased to 20.1 +/- 3.8 mmHg during stress test before PTCA, and only to 14.3 +/- 5.3 mmHg after PTCA (difference highly significant). Before the procedure, negative peak dp/dt during stress test was 1782 +/- 358 mmHg/sec; it increased significantly to 2342 +/- 702 mmHg/sec after PTCA.(ABSTRACT TRUNCATED AT 250 WORDS)