Abstract
To assess left ventricular (LV) systolic and diastolic function globally and regionally and to study the relationship between regional asynchrony and global LV function in patients with stable effort angina pectoris (AP) without previous myocardial infarction, we conducted a resting gated radionuclide ventriculographic study in 15 control subjects (N group) and 22 AP patients with isolated disease of the left anterior descending coronary artery (LAD). In nine of these 22 AP patients, LV systolic and diastolic function before surgical revascularization (Aorto-Coronary Bypass) were compared with those after surgical revascularization. A computer program subdivided the image of the LV into four regions (septal, basal, lateral and apical) by our previously reported method.1, 2 The time-activity and first-derivative curves of the global LV and three regions (septal, lateral, apical; the basal region was not computed) LV were computed. In the global LV, the peak filling rate (PFR) normalized to LV end-diastolic volume (EDV) and the ratio of increment of filling volume at 100 msec from global end-systole (ES) to the EDV (%EFV), which was correlated with the time constant of LV pressure decay during isovolumic relaxation, 3 decreased (p<0.01, p<0.001, respectively) and time to PFR ('time interval from global ES to PFR) was greater (p<0.001) in the AP group than that in the N group. However, in the AP group, the ejection fraction (EF), normalized peak ejection rate (PFR) and %1/3SV, which was defined as the percent stroke volume ejected during the first third of the global LV ejection phase, were not different from these in the N group. With regard to REGIONAL LV FUNCTION, the regional %1/3SV decreased only in the septal region perfused by the stenosed vessel. There were no significant differences in regional EF or PER between the two groups. ASYNCHRONOUS differences in regional EF or PER between the two groups. ASYNCHRONOUS INDEXES were defined as the sum of the absolute value of the time differences between global and regional timing of PER, ES or PFR, and were expressed as TPER, TES, and TPFR, respectively. TES and TPF were significantly greater in the AP group (p<0.01, p<0.001, respectively). A negative correlation existed between TPF and global PFR (r=-0.65, p<0.001). After surgical revascularization, %EFV, PFR and asynchrony at the PFR (TPFR) improved (p<0.05, p<0.01, p<0.01, respectively). There was a good negative correlation between the changes in PFR after A-C Bypass operation and those in TPFR after A-C Bypass (r=0.828, p<0.01). Thus, in AP with one-vessel disease, regional asynchronous wall motion occurs between the side perfused by the stenosed vessel and the normally perfused side in late systole and early diastole, which may cause impairment of global LV filling, and these diastolic impairments are reversible.
