abstract
- BACKGROUND: Many patients with repaired tetralogy of Fallot (TOF) have clinically important pulmonary regurgitation that can eventually lead to right ventricular (RV) dilatation and dysfunction and associated morbidity and mortality. Unfortunately, standard echocardiographic techniques to evaluate RV size and function can be inaccurate. Newer Doppler modalities such as Doppler tissue imaging (DTI) can detect subtle changes in myocardial velocities and may better identify subclinical RV dysfunction in these patients. METHODS: A total of 25 patients with repaired TOF prospectively underwent complete echocardiographic assessment (including DTI) of the RV and cardiopulmonary stress testing to evaluate exercise capacity. Echocardiographic variables were compared with age- and sex-matched control subjects. RESULTS: Patients with repaired TOF had significantly lower RV DTI indices compared with control subjects. In patients with repaired TOF, RV peak systolic velocity had a significant correlation with maximal oxygen consumption during exercise (r = 0.80, P < .001) and was the only independent predictor of maximal oxygen consumption on multivariate analysis (r = 0.80, P < .001). CONCLUSION: DTI identifies abnormalities of RV systolic and diastolic function in patients with repaired TOF. Importantly, RV systolic velocity is predictive of exercise capacity in these patients.