RECOVERY OF THE RIGHT VENTRICLE AFTER SINGLE-LUNG TRANSPLANTATION IN PULMONARY-HYPERTENSION

Single-lung transplantation has been successfully performed in patients with pulmonary fibrosis and emphysema. In contrast, patients with end-stage pulmonary hypertension (either primary or secondary to Eisenmenger's syndrome) have conventionally been offered heart-lung transplantation. The rationale underlying this approach is that chronic pulmonary hypertension results in irreversible right ventricular dilatation and failure. Recovery of the right ventricle has previously been reported after thromboendarterectomy for chronic large-vessel pulmonary embolism, correction of atrial septal defect or mitral valve replacement. The evolution of right ventricular morphology and function after lung transplantation has not been previously described. This study examines the reversibility of right ventricle dysfunction following normalization of pulmonary artery pressure after single-lung transplantation in 4 patients with pulmonary hypertension. Cardiac function was assessed using electrocardiography, echocardiography and radionuclide angiography. Pulmonary hemodynamic measurements, including pulmonary artery pressure and pulmonary vascular resistance, decreased in all patients after single-lung transplantation. Electrocardiographic changes observed were leftward shift in the QRS axis, and a decrease in P-wave amplitude and in right ventricular force. Echocardiographic examination revealed decreased right atrial, right ventricular and tricuspid valve annular dimensions, normalization of septal motion, and decreased tricuspid regurgitation. Thus, improved pulmonary hemodynamics after single-lung transplantation for pulmonary vascular disease results in reversal of right heart dilatation and dysfunction, and improved myocardial performance. The extent of right ventricular dysfunction beyond which recovery is unlikely to occur has yet to be determined.