ATRIAL EMPTYING WITH ORTHOTOPIC HEART-TRANSPLANTATION USING BICAVAL AND PULMONARY VENOUS ANASTOMOSES - A MAGNETIC-RESONANCE-IMAGING STUDY

Objectives. We hypothesized that orthotopic heart transplantation with bicaval and pulmonary venous anastomoses preserves atrial contractili ty. Background. The standard biatrial anastomotic technique of orthoto pic heart transplantation causes impaired function and enlargement of the atria. Cine magnetic resonance imaging (MRI) allows assessment of atrial size and function. Methods. We studied 16 patients who had unde rgone bicaval (n = 8) or biatrial (n = 8) orthotopic heart transplanta tion without evidence of rejection and a control group of 6 healthy vo lunteers. For all three groups, cine MRI was performed by combining co ronal and axial gated spin echo and gradient echo cine sequences. Intr acardiac volumes were calculated with the Simpson rule. Atrial emptyin g fraction was defined as the difference between atrial diastolic and systolic volumes, divided by atrial diastolic volume, expressed in per cent. All patients had right heart catheterization. Results. Right atr ial emptying fraction was significantly higher in the bicaval (mean [/-SD] 37 +/- 9%) than in the biatrial group (22 +/- 11%, p < 0.05) and similar to that in the control group (48 +/- 4%). Left atrial emptyin g fraction,vas significantly higher in the bicaval (30 +/- 5%) than in the biatrial group (15 +/- 4%, p < 0.05) and significantly lower in b oth transplant groups than in the control group (47 +/- 5%, p < 0.05). The left atrium was larger in the biatrial than in the control group (p < 0.05). Cardiac index, stroke index, heart rate and blood pressure were similar in the transplant groups. Conclusions. Left and right at rial emptying fractions are significantly depressed with the biatrial technique and markedly improved with the bicaval technique of orthotop ic heart transplantation. The beneficial effects of the latter techniq ue on atrial function could improve allograft exercise performance.