[Changes in left ventricular dP/dt during transluminal coronary angioplasty]

The authors studied changes of LV dP/dt during transcutaneous coronary angioplasty (TCA). The aim of the study was to detect the alterations of LV function during coronary occlusion and to evaluate the immediate effects of PCA on myocardial function. Six patients with incapacitating angina and isolated left anterior descending disease were successfully treated by TCA using Gruntzig's technique. The study protocol included several recording sequences per patient during the phases of balloon inflation at progressively increasing pressures from 2 to 10 hours. Each sequence comprised a recording under basal conditions and every 5 seconds during inflation (20 seconds) and deflation (45 seconds) of the following parameters: heart rate, aortic and LV pressures, positive and negative peaks of LV dP/dt, and the intracoronary pressure gradient at the beginning and the end of each sequence. The first part of the results based on 27 recorded sequences analysed the bad effects of myocardial ischaemia; coronary occlusion induced a significant fall (p less than 0.01) in the positive and negative peak dP/dt values and on elevation (p less than 0.01) in LV end diastolic pressure, without affecting LV systolic pressure or heart rate. These changes have the following characteristics: they are early, occurring within seconds of coronary occlusion; they affect LV contraction and relaxation simultaneously, but the effects are more marked on LV relaxation; the severity is proportional to the duration of occlusion; they are totally reversible; the disturbances of relaxation return to normal more quickly than those of contraction.(ABSTRACT TRUNCATED AT 250 WORDS)