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

Single-lung transplantation has been successfully performed in patient s with pulmonary fibrosis and emphysema. In contrast, patients with en d-stage pulmonary hypertension (either primary or secondary to Eisenme nger's syndrome) have conventionally been offered heart-lung transplan tation. The rationale underlying this approach is that chronic pulmona ry hypertension results in irreversible right ventricular dilatation a nd failure. Recovery of the right ventricle has previously been report ed after thromboendarterectomy for chronic large-vessel pulmonary embo lism, 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 normalizat ion of pulmonary artery pressure after single-lung transplantation in 4 patients with pulmonary hypertension. Cardiac function was assessed using electrocardiography, echocardiography and radionuclide angiograp hy. Pulmonary hemodynamic measurements, including pulmonary artery pre ssure and pulmonary vascular resistance, decreased in all patients aft er single-lung transplantation. Electrocardiographic changes observed were leftward shift in the QRS axis, and a decrease in P-wave amplitud e and in right ventricular force. Echocardiographic examination reveal ed decreased right atrial, right ventricular and tricuspid valve annul ar dimensions, normalization of septal motion, and decreased tricuspid regurgitation. Thus, improved pulmonary hemodynamics after single-lun g transplantation for pulmonary vascular disease results in reversal o f right heart dilatation and dysfunction, and improved myocardial perf ormance. The extent of right ventricular dysfunction beyond which reco very is unlikely to occur has yet to be determined.