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Aims To evaluate the additional value of dobutamine stress testing in patients with repaired tetralogy of Fallot (TOF) by relating stress imaging parameters at baseline to relevant parameters of clinical condition and right ventricular (RV) size during a serial follow-up. Methods and results We prospectively included 27 patients (14 ± 4 years at baseline), who were studied twice with a 5-year interval. Patients underwent cardiovascular magnetic resonance imaging to assess RV systolic and diastolic function at rest and during dobutamine stress. Normal response to dobutamine was defined as a decrease in RV end-systolic volume, and a increase in RV ejection fraction (EF) during stress. Exercise testing and electrocardiography were performed to determine peak oxygen uptake (peak VO2), QRS duration, and QT interval corrected for heart rate (QTc) interval. RV volumes, QRS duration, and QTc interval increased significantly from baseline to follow-up; peak VO2 tended to decrease (95 ± 20–89 ± 14%, P = 0.086). Response to dobutamine was normal in 26 of 27 patients and remained stable during the follow-up [relative increase in RVEF during stress: +25 ± 9% (baseline) vs. +27 ± 10% (follow-up)]. A smaller relative increase in RVEF during stress at baseline related to a larger relative decrease in peak VO2 during the follow-up (r = 0.59, P = 0.004). No significant associations were found with the relative increase in QRS duration, QTc interval, or RV end-diastolic volume during a 5-year follow-up. Conclusion In a young TOF population, response to dobutamine stress was normal and remained stable during the 5-year follow-up. A smaller increase in RVEF during stress at baseline was predictive for a larger decrease in peak VO2 during the 5-year follow-up. [ABSTRACT FROM PUBLISHER]

Abstract: 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±5.2years) and 21 patients operated for TOF (16.6±5.6years), 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 VO2 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. [Copyright &y& Elsevier]

Abstract: The population of adult survivors with tetralogy of Fallot (TOF) is growing over the last decades due to improvements in perinatal management, intensive care and surgical techniques. Pulmonary regurgitation (PR) plays a crucial role in the long-term outcome of these patients. Although PR may be tolerated well for many years, eventually it may lead to right ventricular (RV) dilatation, RV dysfunction, exercise intolerance, arrhythmia and sudden cardiac death. Cardiovascular magnetic resonance (CMR) imaging is an important tool in the follow-up of patients after TOF repair, because biventricular volumes and function and PR volume and fraction can be measured with great accuracy and reproducibility. CMR imaging studies have identified risk factors for late adverse outcomes in patients after TOF repair. These include increased RV end-diastolic volume (EDV), reduced left ventricular ejection fraction and abnormal RV outflow tract function. Other applications of CMR include stress imaging, assessment of diastolic function and late gadolinium enhancement, which have provided additional insight in the function of the RV. Timing of pulmonary valve replacement (PVR) is controversial and should balance between the preservation of RV function and the need for subsequent PVR surgery, since the life-span of a homograft is limited. Based on CMR imaging studies, PVR will be considered if the RVEDV reaches a threshold of between 150 and 200ml/m2 in the presence of severe PR. However, timing of PVR should be based on multiple factors, other than RV size and PR fraction alone. [Copyright &y& Elsevier]