RIGHT-VENTRICULAR VOLUME OVERLOAD RESULTS IN DEPRESSION OF LEFT-VENTRICULAR EJECTION FRACTION - IMPLICATIONS FOR THE SURGICAL-MANAGEMENT OFTRICUSPID-VALVE DISEASE

Background Right ventricular volume overload (RVVO) occurring in condi tions such as Ebstein's anomaly may result in depression of left ventr icular ejection fraction (LVEF). This study tests this hypothesis by m easuring LVEF in 10 patients with RVVO due to tricuspid valve resectio n for isolated tricuspid valve endocarditis and in 10 age-matched heal thy persons. Methods and Results When the modified Simpson's rule was applied to echocardiographic images, LVEF for patients with RVVO measu red significantly lower than for age-matched healthy subjects (51+/-4% versus 60+/-4%, P<.0001). Depression of LVEF does not result simply f rom reduced venous return to the left ventricle, since left ventricula r end-diastolic volume was not significantly different between patient s with RVVO and age-matched healthy persons (84+/-26 versus 77+/-20 mt , NS). Possible explanations for the depression in LVEF may relate to the decreased relative contribution of left atrial systole to left ven tricular filling (demonstrated by transmitral pulsed Doppler) or to th e mechanical effects of ventricular septal paradox (demonstrated by th e abnormal leftward ventricular septal flattening and increase in shor t-axis cavity eccentricity at end diastole, which returns to normal at end systole) in patients with RVVO. Conclusions These findings sugges t that surgical excision of the tricuspid valve results in isolated RV VO, which creates not only diastolic overload of the right heart but a lso depression of LVEF.