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 coronary artery disease, the authors investigated two groups of patients. In group I, all 12 patients (mean age 47 +/- 7 years) exhibited evidence of a normal heart after an extensive investigation. In group II, 25 patients (55 +/- 7 years) presented an isolated stenosis of the left anterior descending coronary artery, and they underwent a hemodynamic investigation before and after (six to nine months) a durable successful percutaneous transluminal coronary angioplasty (PTCA). After all conventional hemodynamic measurements had been done, a quantitative frame-by-frame analysis of left ventricular wall motion was conducted. The authors' method is derived from that of Ingels, applying to LV cineangiograms filmed in 30 degrees right anterior oblique view at a 50 frames/second rate. Thus segmental wall motion is analyzed in terms of amplitudes (%), velocities of shortening and lengthening in circumferences/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 asynergic motion of the anterior region taking place from end systole to early diastole 1. Early end of contraction in anterior segments (% of systolic time interval 88 +/- 14% vs 96 +/- 6% in group I, p less than 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 less than 0.02) 3. An early but poor outward anterior wall motion (anterior lengthening at 0.04 sec after the end of ejection 2.9 +/- 10% in group II versus 5.4 +/- 7.2% in group I, p less than 0.05) These abnormalities are strongly correlated with a significant impairment of peak negative diastolic pressure/diastolic time (dP/dt) (1500 +/- 400 mmHg. sec-1 vs 1850 +/- 410 in group I, p less than 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 segmental motion, this one being correctly analyzed and quantified on LV cineangiograms with our method.