Asymmetry of right ventricular enlargement in response to tricuspid regurgitation

Background-Analysis of right ventricular adaptation to tricuspid regurgitat ion was studied in 10 heart transplant recipients following inadvertent end omyocardial biopsy disruption of the tricuspid apparatus. Methods and Results-Echocardiography demonstrated progressive diastolic rig ht ventricular cavity enlargement (19.5+/-5.0 to 30.3+/-5.4 cm(2), P<0.0002 ), with disproportionate elongation along the midminor axis (3.5+/-0.6 to 5 .0+/-0.5 cm, P<0.001). As the right ventricle remodeled to more spherical l and less elliptical) proportions, the end-diastolic right ventricular midmi nor axis/long axis ratio increased significantly from 0.52+/-0.10 to 0.68+/ -0.07, P<0.005. Conclusions-Ventricular enlargement due to right ventricular volume overloa d results in disproportionate dilation along the free wall to septum minor axis.