Long-Term Beneficial Effects of PTCA on Segmental Early Relaxation in Disease of the Left Anterior Descending Coronary Artery

Abstract

The relationship between regional left ventricular (LV) motion and global pressure relaxation of the left ventricle remains unclear. To clarify the recent concept of segmental early relaxation in coro nary artery disease, the authors in vestigated two groups of patients. In group I, all 12 patients (mean age 47±7 years) exhibited evidence of a normal heart after an extensive in vestigation. In group II, 25 patients (55±7 years) presented an isolated stenosis of the left anterior descend ing coronary artery, and they under went a hemodynamic investigation before and after (six to nine months) a durable successful percutaneous transluminal coronary angioplasty (PTCA). After all conventional hemody namic measurements had been done, a quantitative frame-by-frame analy sis of left ventricular wall motion was conducted. The authors' method is derived from that of Ingels, applying to LV cineangiograms filmed in 30° right anterior oblique view at a 50 frames/second rate. Thus segmental wall motion is analyzed in terms of amplitudes (%), velocities of shorten ing and lengthening in circumfer ences/second (circ/sec), and times of events (%). Statistical results took into account the reproducibility of the method. Main results regarding the control state of group II consisted of an asy nergic motion of the anterior region taking place from end systole to early diastole: 1. Early end of contraction in an terior segments (% of systolic time in terval : 88±14% vs 96±6% in group I, p < 0.001) 2. Asynchronism at end systole (maximal velocity of shortening — 0.4±2.3 circ/sec in anterior segments vs 0.05±1.9 in inferior segments, p < 0.02) 3. An early but poor outward an terior wall motion (anterior lengthen ing at 0.04 sec after the end of ejec tion 2.9±10% in group II versus 5.4±7.2% in group I, p < 0.05) These abnormalities are strongly correlated with a significant impair ment of peak negative diastolic pres sure/diastolic time (dP/dt) (1500 ±400 mmHg. sec-1 vs 1850±410 in group I, p < 0.02). Long-term beneficial effects of PTCA in group II were characterized by an almost complete normalization, both asynergy and relaxation taking place back within the normal range. The authors conclude that in this kind of patient, peak negative dP/dt could be an index of an asynergic seg mental motion, this one being cor rectly analyzed and quantified on LV cineangiograms with our method.