ECHOCARDIOGRAPHIC CHARACTERIZATION OF THE IMPROVEMENT IN RIGHT-VENTRICULAR FUNCTION IN PATIENTS WITH SEVERE PULMONARY-HYPERTENSION AFTER SINGLE-LUNG TRANSPLANTATION

Objectives. This study was designed to characterize immediate, early and long-term changes in right ventricular structure and function, as defined by two-dimensional and Doppler echocardiography, after single-lung transplantation in patients with severe pulmonary hypertension. Background. Single-lung transplantation has recently been shown to dramatically improve hemodynamics in patients with primary pulmonary hypertension who had unsuccessful medical therapy. Methods. Fourteen patients with severe pulmonary hypertension who underwent single-lung transplantation were studied with transthoracic and transesophageal two-dimensional and Doppler echocardiography. Right ventricular dimensions were measured in the apical four-chamber view. Right ventricular ejection and acceleration times and peak velocity of tricuspid regurgitation were measured by Doppler study. Results of right heart catheterization were available early (<3 months) after transplantation in 10 of 13 patients and late after transplantation (6 months to 2 years) in 11 patients. Results. In the early posttransplantation studies, right ventricular dimensions decreased and fractional area change and ejection fraction increased in all patients, but right ventricular wall thickness did not change significantly. Tricuspid regurgitation lessened markedly in all patients. Long-term decreases in right ventricular dimension and improvement in systolic function were sustained. Right ventricular wall thickness significantly decreased compared with the early postoperative value (0.76 +/- 0.1 cm compared with 0.63 +/- 0.14 cm, p < 0.02). Conclusions. Two-dimensional echocardiography demonstrates sustained improvement in right ventricular function after single-lung transplantation for severe pulmonary hypertension despite severe preoperative dysfunction.