Tricuspid valve surgery improves cardiac output and exercise performance in patients with Ebstein's anomaly.

BACKGROUND: Clinical, hemodynamic and functional effects of tricuspid valve surgery in patients with Ebstein's anomaly are not well understood.
METHODS: Sixteen patients (median age of 27.7 years) were examined before and eight months after surgery by means of echocardiography, cardiovascular magnetic resonance (CMR) and cardiopulmonary exercise testing.
RESULTS: Peak work load (1.87 to 2.0W/kg; p=0.026), maximum oxygen uptake (21 to 22 ml/kg/min; p=0.034) as well as cardiac output (2.7 to 2.9l/min/m(2); p=0.035) increased postoperatively. The reduction of tricuspid regurgitation led to a higher pulmonary stroke volume (29 to 42ml/m(2), p=0.005) and augmented the left ventricular (LV) volume (55 to 63ml/min/m(2); p=0.001) with a trend to better ejection fraction (61 to 64%; p=0.083). Right ventricular (RV) volume index (124 to 108ml/m2; p=0.034) and ejection fraction (50 to 42%; p=0.036) decreased on CMR. Echocardiographic measurements of RV function also decreased (tricuspid annular plane systolic excursion 2.3 to 1.7; p=0.002; isovolumic acceleration 0.98 to 0.65; p=0.004; and 2-d longitudinal global strain -19.3 to -16.25; p=0.006).
CONCLUSION: Tricuspid valve surgery improves exercise capacity in patients with Ebstein's anomaly. The reduction of tricuspid regurgitation decreases the volume of the right ventricle and increases pulmonary antegrade flow. As a result LV volume and cardiac output increase. This hemodynamic benefit occurs despite the preload dependent reduction in RV volume and ejection fraction.