[The left ventricular function in bicycle ergometric stress before and after aortocoronary bypass surgery]

Biplane left ventricular cineangiograms and pressure measurements were performed in 44 patients with coronary heart disease at rest and during submaximal or symptom-limited supine bicycle exercise before and 7 +/- 3 months after bypass surgery. Revascularization was complete in 12 (group 1) and incomplete in 32 patients (group II). Preoperative left ventricular ejection fraction (EF) was within normal limits at rest and declined during exercise in both groups (group I from 59 to 51%, p less than 0.01; group II from 61 to 48%, p less than 0.001). Postoperative EF at rest was nearly identical to preoperative EF in both groups and remained unchanged during exercise (group I from 65 to 63%; group II from 58 to 56%). Peak systolic pressure to end-systolic volume index ratio (LVSP/ESVI in mm Hg/ml . m-2) also decreased during exercise in both groups peroperatively (group I from 3.7 to 3.2 [n.s.]; group Ii from 3.4 to 2.6, p less than 0.005). Postoperative LVSP/ESVI at rest was again unchanged as compared to preoperative LVSP/ESVI. During exercise, however, it increased in both groups, reaching higher values in group I than in group II (5.1 vs. 3.7, p less than 0.05). Whereas both parameters indicate improvement of global left ventricular function following surgery, LVSP/ESVI also suggests more marked recovery of function in patients with complete revascularization than in those where revascularization is incomplete.