[Evaluation of left ventricular function and coronary sinus blood flow during exercise after aortocoronary bypass surgery. Influence of revascularization of the left anterior descending artery].

Left ventricular function and coronary sinus blood flow at rest and during exercise were evaluated in 27 patients after aortocoronary bypass surgery and in 13 normal subjects (G-C). Twenty patients (G-1) had successfully revascularized left anterior descending artery (LAD). In 7 patients (G-2), the revascularization for LAD was not complete. There was no difference among 3 groups in stroke work index (SWI), left ventricular end-diastolic pressure (LVEDP) and coronary sinus blood flow (CSF) at rest. SWI during exercise in G-2 (44.7 +/- 14.7 g. M/beat/m2) was significantly lower than that in G-1 and G-C (67.9 +/- 15.0, 77.2 +/- 17.0 g.M/beat/m2) (p less than 0.02, p less than 0.002). LVEDP during exercise in G-2 (32 +/- 6 mmHg) was significantly higher than that in G-1, G-C (17 +/- 7, 13 +/- 3 mmHg) (p less than 0.001, p less than 0.001). CSF during exercise in G-2 (160 +/- 64 ml/min) was significantly lower than that in G-1, G-C (357 +/- 79, 290 +/- 113 ml/min) (p less than 0.001, p less than 0.002). These data indicated that left ventricular function during exercise and coronary sinus blood flow reserve for exercise in patient with completely revascularized LAD was significantly better than that in patients with incompletely revascularized LAD.