Left ventricular assist device (LVAD) is being used increasingly in recent years for end stage heart failure as a bridge to transplant (BTT) and also as a destination therapy (DT). Patients with end stage heart failur...Left ventricular assist device (LVAD) is being used increasingly in recent years for end stage heart failure as a bridge to transplant (BTT) and also as a destination therapy (DT). Patients with end stage heart failure have some degree of elevated pulmonary capillary wedge pressure, causing right ventricular hypertrophy which in due course leads to decreased dilatation of the RV and fall in cardiac output & severe tricuspid regurgitation (TR) presenting with features of RV failure (RVF). Implantation of LVAD improves left heart function at the cost of right ventricular output with an incidence of 25%-30%. RVF may lead to impaired LVAD flow, difficulty in weaning from cardio-pulmonary bypass (CPB), decreased tissue perfusion and multi-organ failure. In this article we comprehended the pathophysiology leading to RVF post LVAD implantation and its preoperative predictors and the various treatment modalities for managing RVF post LVAD implantation.展开更多
The efficacy of right atrial-pulmonary artery (RA-PA) bypass during acute right ventricular failure (RVF) produced by pulmonary artery constriction in dogs was examined in this study Control group (n=7) was supported ...The efficacy of right atrial-pulmonary artery (RA-PA) bypass during acute right ventricular failure (RVF) produced by pulmonary artery constriction in dogs was examined in this study Control group (n=7) was supported with conventional volume loading and inotropic therapy. In the experimental animals (n=8) , RA-PA bypass was initiated 5 min. after the onset of severe RVF. Three control animals died from refractory ventricular fibrillation within one hour of RVF. No animals in the experimental group died within two hours of RA-PA bypass , but the histological study of the lungs in these animals demonstrated peribronchial , perivascular and intraalveolar hemorrhage. Light microscopic and electron microscopic examination of the myocardial specimens of the right ventricular free wall displayed the myocardial structures and ultrastructures were maintained effectively with RA-PA bypass while irreversible myocardial injuries occurred in the control animals after two hours of RVF with conventional therapy. During the 2 hours of RA-PA bypass, the hemodynamic indices were also maintained better when compared to the control animals. It may be concluded , a roller pump right ventricular assist device effectively unloads the acute failing right ventricle, maintains systemic cardiac output , and significantly reverses the myocardial ischemia during right ventricular failure, but RA-PA bypass may induce pulmonary hypertension due to increased pulmonary vascular resistance secondary to pulmonary edema and interstitial hemorrhage.展开更多
文摘Left ventricular assist device (LVAD) is being used increasingly in recent years for end stage heart failure as a bridge to transplant (BTT) and also as a destination therapy (DT). Patients with end stage heart failure have some degree of elevated pulmonary capillary wedge pressure, causing right ventricular hypertrophy which in due course leads to decreased dilatation of the RV and fall in cardiac output & severe tricuspid regurgitation (TR) presenting with features of RV failure (RVF). Implantation of LVAD improves left heart function at the cost of right ventricular output with an incidence of 25%-30%. RVF may lead to impaired LVAD flow, difficulty in weaning from cardio-pulmonary bypass (CPB), decreased tissue perfusion and multi-organ failure. In this article we comprehended the pathophysiology leading to RVF post LVAD implantation and its preoperative predictors and the various treatment modalities for managing RVF post LVAD implantation.
文摘The efficacy of right atrial-pulmonary artery (RA-PA) bypass during acute right ventricular failure (RVF) produced by pulmonary artery constriction in dogs was examined in this study Control group (n=7) was supported with conventional volume loading and inotropic therapy. In the experimental animals (n=8) , RA-PA bypass was initiated 5 min. after the onset of severe RVF. Three control animals died from refractory ventricular fibrillation within one hour of RVF. No animals in the experimental group died within two hours of RA-PA bypass , but the histological study of the lungs in these animals demonstrated peribronchial , perivascular and intraalveolar hemorrhage. Light microscopic and electron microscopic examination of the myocardial specimens of the right ventricular free wall displayed the myocardial structures and ultrastructures were maintained effectively with RA-PA bypass while irreversible myocardial injuries occurred in the control animals after two hours of RVF with conventional therapy. During the 2 hours of RA-PA bypass, the hemodynamic indices were also maintained better when compared to the control animals. It may be concluded , a roller pump right ventricular assist device effectively unloads the acute failing right ventricle, maintains systemic cardiac output , and significantly reverses the myocardial ischemia during right ventricular failure, but RA-PA bypass may induce pulmonary hypertension due to increased pulmonary vascular resistance secondary to pulmonary edema and interstitial hemorrhage.
