Exercise capacity and ventricular function in patients treated for isolated pulmonary valve stenosis or tetralogy of Fallot.

BACKGROUND: We hypothesized 1) that long-term ventricular outcome and exercise capacity would be better in patients with isolated pulmonary valve stenosis (PS) treated with balloon pulmonary valvuloplasty (BPV) than in patients operated for tetralogy of Fallot (TOF), and 2) that ventricular outcome and exercise capacity would not be different in PS patients and healthy controls.

METHODS: We included 21 PS patients after BPV (16.2 ± 5.2 years) and 21 patients operated for TOF (16.6 ± 5.6 years), matching them for gender, age at treatment, and age at study. Patients underwent cardiovascular magnetic resonance (CMR) imaging, exercise testing, 12-lead ECG and 24-hour Holter monitoring for assessment of right ventricular (RV) size and function, pulmonary regurgitation (PR), exercise capacity and electrocardiographic status. Healthy controls for CMR imaging and exercise testing were matched for gender and age at study.

RESULTS: RV volumes and PR percentage were significantly larger in TOF patients than in PS patients; biventricular ejection fraction (EF) was not different. PR was mild in most PS patients. RV end-systolic volume was significantly larger in PS patients than in healthy controls; RVEF was significantly lower. Both patient groups had similar exercise test results. Peak workload and VO(2) max. were significantly lower in PS patients than in healthy controls.

CONCLUSIONS: Longstanding mild PR in PS patients can lead to an enlarged RV, reduced RV function and reduced exercise capacity. Despite more PR and larger RV volumes in TOF patients, exercise capacity and biventricular function are similar in both patient groups.