Evaluation of left ventricular function utilizing transesophageal echocardiography during and after thoracic aortic aneurysm repair.
This study was designed to evaluate left ventricular (LV) function during aortic cross-clamping (ACC) by comparing left heart bypass (LHB) with a centrifugal pump and simple aortic cross-clamping (SC). The end-diastolic volume index (EDVI), ejection fraction (EF), fractional shortening (FS) and end-systolic meridional stress (ESS) were measured by transesophageal echocardiography. The measurements were performed 1) before ACC, 2) 2 min after ACC, 3) 20 min after ACC, 4) 2 min after unclamping and 5) 1 h after unclamping. With cross-clamping, a significant decrease was observed in both EDVI (108 vs 83 ml/m2) and EF (73 vs 67%) in patients with LHB. Patients utilizing SC showed a sustained increase in ESS (43 vs 64 10(3) dyne/cm2). The systolic blood pressure did not vary during LHB, but a transient increase occurred in patients with SC. With release of the cross-clamping, EDV and EF returned to the baseline values in patients with LHB. A significant decrease occurred in EDVI (101 vs 71 ml/m2) and ESS (61 vs 36 10(3) dyne/cm2) in the SC group. We conclude that circulatory support with LHB may offer greater stability of the LV function during thoracic aortic cross-clamping than SC because of the lower preload and afterload.
Division of Cardiovascular Surgery, Osaka Prefectural Hospital, Japan.
H
H
Imagawa
H
H
Takano
M
M
Kato
Y
Y
Yoshioka
K
K
Ohnishi
D000368:Aged; D000369:Aged, 80 and over; D017545:Aortic Aneurysm, Thoracic / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000601:surgery*; D001794:Blood Pressure; D006348:Cardiac Surgical Procedures / Q000379:methods; D004452:Echocardiography / Q000379:methods; D004947:Esophagus; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D011182:Postoperative Care; D013318:Stroke Volume / Q000502:physiology; D016277:Ventricular Function, Left / Q000502:physiology*