LAUSR

Right ventricular-pulmonary arterial (RV-PA) coupling is an important determinant in the development of right ventricular dilatation. RV-PA coupling is defined as the ratio of pulmonary arterial elastance (an index of arterial load) and right ventricular end-systolic elastance (an index of contractility). A retrospective study of post operative 135 TOF patients who underwent for pulmonary valve replacement (PVR) was conducted. RV-PA coupling was calculated noninvasively using Ea/Emax (CMR) =ESV/SV, equation and patients were divided into coupling and uncoupling group and compared the results on the basis of echocardiography and cardiopulmonary exercise test. Lower TAPSE, percentage predictive peak VO2, VE/VCO2 at AT, VE/VCO2 at peak, VE VCO2 slope, VO2 (WR) slope and WR at VO2 peak were identified as risk factors for uncoupling of RV-PA. In RV-PA coupling combination of echocardiography and cardiopulmonary exercise test revealed the most important modality to identify risk factor and may be useful for therapeutic decision making by identifying patients of especially high risk for inadequate therapy.