RIGHT-VENTRICULAR FUNCTION IN ORTHOTOPIC TOTAL ATRIOVENTRICULAR HEART-TRANSPLANTATION

Background: Total orthotopic heart transplantation was recently introd uced into clinical practice as an alternative technique of orthotopic heart transplantation, adding bicaval and left and right pulmonary vei n anastomoses to pulmonary artery and ascending aorta connection (tota l technique). The conventional technique (ventricular transplantation with atrioplasty) is compared with the total technique with particular emphasis on right ventricular performance, Methods: Forty-eight mongr el dogs (23 to 31 kg) were used for 12 total and 12 standard orthotopi c heart transplantations. Right ventricular (RV) function and atrial s ystole were analyzed with the use of micromanometry, sonomicrometry, a nd ultrasonic flow probes (preload-independent RV recruitable stroke w ork, RVPRSW). Fourier analysis was used to calculate RV power and pulm onary vascular impedance. Results: There was no significant difference in cardiac ischemic and bypass times between the two groups. After tr ansplantation, sinus rhythm was preserved after all total transplantat ions and after only one standard transplantation; no significant hemod ynamic differences were observed. RVPRSW in the total group was conser ved after transplantation; however, RVPRSW decreased by 39% (+/-8, p < .05) in the standard group. There was also a significant decrease in t he rate of RV filling in the standard group after transplantation, sug gesting decreased right atrial function. Pulmonary vascular impedance and RV power output were not significantly different after transplanta tion between the two groups.Conclusions: Total atrioventricular transp lantation is a feasible alternative and conserves normal sinus rhythm. Ischemic and bypass times were not significantly different when the s uperior vena cava anastomosis is performed last after the release of t he aortic cross-clamp, The insignificant decrease in the rate of RV fi lling with the use of the total technique suggests conserved RV diasto lic function after transplantation with less decreased RV function in the total group.