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Byline: Inderpaul Birdi, Idris Regragui, Mohammed B. Izzat, Alan J. Bryan, Gianni D. Angelini Abstract: Objectives: Normothermic cardiopulmonary bypass has been proposed as a more physiologic technique than hypothermic bypass for the maintenance of the body during cardiac surgery. The aims of this study were to investigate the effects of systemic perfusion temperature on clinical outcome after coronary revascularization. Methods: Three hundred patients (mean age 60 [+ or -] 9 years, 88% male) were prospectively randomized into three groups: hypothermia (28[degrees] C, n = 100), moderate hypothermia (32[degrees] C, n = 100), and normothermia (37[degrees] C, n = 100). All patients received cold antegrade St. Thomas' Hospital crystalloid cardioplegic solution, and patients in the normothermic group were actively rewarmed during cardiopulmonary bypass (nasopharyngeal temperature 37[degrees] C). Results: No differences were found between groups with respect to mortality (1%), intraaortic balloon pump use, perioperative infarctionrates, focal neurologic deficits (1%), intubation time, intensive care unit stay, and postoperative hospital stay. Further stepwise regression analysis identified age and intensive care unit stay as important predictors of the variability in postoperative stay (both R.sup.2 = 0.114, p < 0.001), whereas perfusion temperature remained a nonsignificant explanator. Normothermic perfusion necessitated larger doses of phenylephrine to maintain arterial pressure above 50 mm Hg during cardiopulmonary bypass (p < 0.0001 vs 28[degrees] C, p < 0.01 vs 32[degrees] C) but less requirement for electrical defibrillation during reperfusion (p < 0.05 vs 32[degrees]C, p < 0.01 vs 28[degrees] C). Total chest drainage was not different between groups, but patients undergoing normothermic cardiopulmonary bypass required less transfusion of blood (p < 0.05 vs 28[degrees] C and 32[degrees] C) and platelets (p < 0.04 vs 32< C, p < 0.001 vs 28[degrees] C) in the postoperative period. Conclusions: Cardiopulmonary bypass temperature did not influence early clinical outcome after routine coronary artery bypass operations. Normothermic systemic perfusion was associated with an increased requirement for vasoconstrictors and reduced requirements for electrical defibrillation and transfusion of blood products. (J Thorac Cardiovasc Surg 1997;114:475-81) Article History: Received 25 November 1996; Revised 13 February 1997; Revised 31 March 1997; Accepted 1 April 1997 Article Note: (footnote) [star] Supported by the Garfield Weston Trust and the British Heart Foundation., [star][star] Address for reprints: G. D. Angelini, FRCS, British Heart Foundation Professor of Cardiac Surgery, Bristol Heart Institute, Bristol Royal Infirmary, Bristol, BS2 8HW, United Kingdom., a 12/1/82349

Byline: Mohammad Bashar Izzat, Inderpaul Birdi, Peter Wilde, Alan J. Bryan, Gianni D. Angelini Abstract: Dobutamine stress Doppler echocardiography was used to compare the hemodynamic performance of two small aortic bileaflet prostheses. Nineteen patients (14 female, mean age 64 years) who had undergone aortic valve replacement with 21 mm bileaflet valve prostheses (St. Jude Medical valve, n = 9, or CarboMedics valve, n = 10) were studied. Dobutamine infusion was started at a rate of 5 [mu]g * kg.sup.-1 * min.sup.-1 and increased to 10 and 20 [mu]g * kg.sup.-1 * min.sup.-1 at 15-minute intervals. Under maximum stress, heart rate and cardiac output increased by 70% and 120%, respectively, and mean arterial blood pressure decreased by 9%. Pulsed-wave and continuous-wave Doppler studies were performed at rest and at the end of each stage. Velocity ratio, effective orifice area, performance index, and discharge coefficient of the valve were calculated, and peak and mean velocities and pressure drops across the prostheses were measured. Dobutamine infusion produced similar increases in cardiac output in all patients. Effective orifice areas, discharge coefficients, and performance indexes were comparable for the two valve groups both at rest and maximum stress. Transvalvular velocities and pressure drops were also similar in the two valve groups. Transvalvular pressure drops were also comparable in patients with large body surface area. Dobutamine stress echocardiography is useful in the evaluation of the hemodynamic performance of prosthetic heart valves. St. Jude Medical and CarboMedics 21 mm prostheses have equally favorable hemodynamic performances in most patients under conditions of high cardiac output. (J THORAC CARDIOVASC SURG 1996;111:408-15) Author Affiliation: Bristol, United Kingdom Article History: Received 16 January 1995; Accepted 9 May 1995 Article Note: (footnote) [star] From the Departments of Cardiac Surgerya and Cardiac Radiology,b University of Bristol and Bristol Royal Infirmary, Bristol, United Kingdom., [star][star] Supported by the British Heart Foundation and the Garfield Weston Trust., a Address for reprints: Gianni D. Angelini, FRCS, British Heart Foundation, Professor of Cardiac Surgery, Bristol Royal Infirmary, Bristol BS2 8HW, United Kingdom., aa 0022-5223/96 $5.00 + 0, acents 12/1/66829

Byline: Andrew M.S. Black (a), Inderpaul Birdi (b), Alan J. Bryan (b), Gianni D. Angelini (b) Author Affiliation: (b) The Bristol Heart Institute Department of Anesthesia (a) University of Bristol Bristol Royal Infirmary Bristol BS2 8HW, United Kingdom