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Left ventricular function during exercise before and after bypass surgery
Insights
Coronary artery bypass surgery improved global left ventricular function in patients with heart disease. Complete revascularization showed a more significant recovery of function compared to incomplete procedures.
Area of Science:
- Cardiology
- Cardiac Surgery
- Cardiovascular Physiology
Background:
- Coronary heart disease (CHD) significantly impacts left ventricular (LV) function.
- Bypass surgery is a common intervention for CHD, but its effect on LV mechanics requires detailed assessment.
Purpose of the Study:
- To evaluate the impact of bypass surgery on global left ventricular function in patients with coronary heart disease.
- To compare the functional recovery between patients with complete versus incomplete revascularization.
Main Methods:
- Biplane left ventricular cineangiograms and pressure measurements were conducted in 44 CHD patients.
- Assessments were performed at rest and during exercise before and after bypass surgery.
- Patients were categorized into complete (Group I) and incomplete (Group II) revascularization groups.
Main Results:
- Preoperative LV ejection fraction (EF) declined during exercise in both groups.
- Postoperative EF at rest and during exercise remained similar to preoperative values.
- The peak systolic pressure to end-systolic volume index (LVSP/ESVI) ratio decreased with exercise preoperatively.
- Postoperatively, LVSP/ESVI increased during exercise, with higher values observed in the complete revascularization group (Group I).
Conclusions:
- Bypass surgery leads to an improvement in global left ventricular function post-procedure.
- Complete revascularization appears to facilitate a more substantial recovery of LV function compared to incomplete revascularization.
Abstract:
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 I) and incomplete in 32 patients (group II). Preoperative left ventricular ejection fraction (EF) was within normal limits at rest and declined similarly 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 (group I, 65%; group II, 58%) and remained unchanged during exercise (group I, 63%; group II, 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 preoperatively (group I from 3.7 to 3.2, NS; 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 patients of group I than of group II (5.1 versus 3.7, p less than 0.05). Whereas both parameters indicate an improvement in global left ventricular function following surgery, LVSP/ESVI even suggests a more sizable recovery of function in patients with complete as compared to those with incomplete revascularization.