Evaluation of right ventricular functions and B-type natriuretic peptide levels by cardiopulmonary exercise test in patients with pulmonary regurgitation after repair of tetralogy of Fallot.

Impairment of right ventricular functions, especially due to chronic pulmonary regurgitation (PR), is a well-known entity in patients with tetralogy of Fallot (ToF) after repair. The aim of this study was to examine the relation between B-type natriuretic peptide (BNP) levels and right ventricular dysfunction by cardiopulmonary exercise test (ET) in patients after repair of ToF. Twenty-five patients with a mean age of 14.1 +/- 4.4 years at follow-up who underwent repair of ToF at a mean age of 4.9 +/- 5.1 years and 29 age- and sex-matched healthy children at a mean age of 13.1 +/- 2.8 years were enrolled in this study. Plasma BNP levels were measured at baseline and at maximal exercise. The volume of right ventricle (RV) and the degree of PR were assessed by two-dimensional echocardiography and color Doppler. Plasma BNP levels were significantly higher in patients with ToF than in controls (28.3 +/- 24.1 vs 7.4 +/- 2.3 pg/mL, p = 0.0001). Exercise was associated with increased plasma BNP levels in both groups. A greater increase in BNP was noted in patients with ToF than in controls (37.6 +/- 27.5 vs 11.3 +/- 4.5 pg/mL, p = 0.0001). Forced vital capacity (FVC%) (84.9 +/- 16.9 vs 98.4 +/- 18.2, p = 0.01) and forced expiratory volume during the 1st second (FEV1%) (91.5 +/- 19.3 vs 103.8 +/- 16.1, p = 0.02) were decreased, exercise duration (ED) (10.1 +/- 1.9 vs 11.4 +/- 1.7 min, p = 0.02), maximum heart rate (HRmax) (171.2 +/- 18.9 vs 186.4 +/- 13.9 /min, p = 0.004), and maximum oxygen uptake (VO(2)max) (1.56 +/- 0.53 vs 2.1 +/- 0.6 L/min, p = 0.007) were lower in patients with ToF. There were significant correlations between the degree of PR and ED (r =-0.3, p = 0.009), HRmax (r =-0.4, p = 0.001), and VO(2)max (r =-0.4, p = 0.001). The correlations were significant both before and after exercise, being more pronounced after exercise between BNP level and the degree of PR (r = 0.6, p = 0.0001). As a result, the severity of PR has a negative influence on right ventricular functions and there is significant relation between right ventricular functions and exercise capacity after repair of tetralogy of Fallot.