Asymmetry of Right Ventricular Enlargement in Response to Tricuspid Regurgitation

Background—Analysis of right ventricular adaptation to tricuspid regurgitation was studied in 10 heart transplant recipients following inadvertent endomyocardial biopsy disruption of the tricuspid apparatus. Methods and Results—Echocardiography demonstrated progressive diastolic right ventricular cavity enlargement (19.5±5.0 to 30.3±5.4 cm2, 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 (and less elliptical) proportions, the end-diastolic right ventricular midminor 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 overload results in disproportionate dilation along the free wall to septum minor axis.