ATRIOVENTRICULAR VALVE INSUFFICIENCY AND ATRIAL GEOMETRY AFTER ORTHOTOPIC HEART-TRANSPLANTATION

Background. The etiology of tricuspid and mitral valve regurgitation ( TR and MR) after heart transplantation is still controversial. Methods . We studied 25 patients undergoing transplantation and intraoperative transesophageal echocardiography to evaluate the incidence, the degre e, and the cause of TR and MR. The degree of valve regurgitation was a ssessed by color Doppler echocardiography. Cross-sectional areas of th e recipient (R) and donor (D) portions of the atria and their ratio (R /D) were measured to assess the distortion of atrial geometry. Tricusp id and mitral valve annuli, their systolic shortening, and hemodynamic indices were measured preoperatively and perioperatively. Results. Tr icuspid valve regurgitation was found in 21 of 25 patients (84%) and M R in 12 of 25 (48%). The degree of MR was mild, whereas TR was mild to moderate. Mitral valve regurgitation did not show any correlation wit h the studied indices; TR showed no correlation with the hemodynamic i ndices but a significant correlation with R/D ratio (r = 0.90; standar d error of the estimate = 0.2). An inverse correlation was found betwe en the degree of TR and systolic shortening of tricuspid annulus (r = -0.88; standard error of the estimate = 0.03) and between R/D ratio an d systolic shortening of tricuspid annulus (r = -0.85; standard error of the estimate = 0.04). Conclusions. Tricuspid valve regurgitation ha s a higher incidence than MR and occurs immediately after transplantat ion; MR is mild and correlates with neither hemodynamic indices nor at rial distortion. An increased R/D ratio, and hence distortion of right atrial geometry, may lead to a reduction in systolic annulus shorteni ng, which in turn causes TR. Surgical attempts to reduce the R/D ratio may decrease the incidence and the degree of TR after heart transplan tation.