EVALUATION OF HEPATIC VENOUS FLOW USING TRANSESOPHAGEAL ECHOCARDIOGRAPHY IN CORONARY-ARTERY BYPASS-SURGERY - AN INDEX OF RIGHT-VENTRICULAR FUNCTION

Hepatic venous flows (HVFs) were evaluated to assess right-heart funct ion by transesophageal Doppler echocardiography in 45 patients undergo ing coronary artery bypass graft (CABG) surgery. Peak velocity and tim e velocity integral of A-wave (reverse flow in end diastole), S-wave ( forward flow in systole), V-wave (reverse flow in late systole), and D -wave (forward flow in diastole) of biphasic HVF were examined. Peak s ystolic-diastolic ratio (S/D) of biphasic HVF and reverse flow ratio ( % reversal flow/forward flow [RF/FF]) of both biphasic and monophasic HVF also were examined. Tricuspid regurgitation (TR) was assessed by c olor Doppler image. All data were obtained after performing the follow ing: induction of anesthesia (stage 1); pericardiectomy (stage 2); car diopulmonary bypass (CPB) (stage 3); and closure of sternum (stage 4). HVFs at stage 1 were obtained in all 45 patients, and the peak S/D in patients with a history of inferior wall myocardial infarction (MI) w as significantly less than that in patients without a history of MI (p < 0.05). HVFs of 35 patients were recorded successfully at all stages . In 5 of these 35 patients, HVF patterns became monophasic after CPB, and only one of those patients had severe TR. In the rest of the 30 p atients with biphasic patterns throughout the operation, peak A and D velocities increased (p < 0.01), whereas peak S and V velocities decre ased (p < 0.01) after CPB compared with those before CPB. Consequently , peak S/D was reduced (p < 0.01), and %RF/FF increased (p < 0.05). Th ese post-CPB changes were associated with increased (p < 0.01) pulmona ry artery diastolic and right atrial pressures. Thus, this study indic ates that before CPB, low peak S/D without significant TR could be ind icative of reduced right ventricular (RV) systolic function in patient s with a history of inferior MI. After CPB, reduced peak S/D and incre ased %RF/FF may be indicative of a decrease in RV function secondary t o the operative procedure and/or poor protection of the right heart. C opyright (C) 1995 by W.B. Saunders Company