Pulmonary thromboendarterectomy (PTE) reverses chronic thromboembolic pulmonary hypertension, decreasing pulmonary vascular resistance and pressure overload failure of the right ventricle (RV). Suboptimal cardiac function early after PTE on cardiopulmonary bypass (CPB) may require inotropic or mechanical support. Our laboratory demonstrated increased cardiac output (CO) with temporary biventricular pacing (BiVP) in an RV pressure overload pig model. In patients with left ventricular (LV) dysfunction, optimized temporary BiVP increases CO after CPB, reduces the vasoactiveinotrope score, and increases urine output. Our study tests the feasibility of BiVP reversal of RV failure after PTE.