| In about 10% of patients with congenital heart disease a univentricular type of defect is diagnosed. The Fontan procedure has significantly improved survival in these patients, but the single ventricle faces abnormal loading conditions after Fontan repair. Combined with regional function abnormalities and afterload mismatch this results in important long-term mortality and morbidity. Neurohormonal activation and ventricular remodeling are initial signs of impending heart failure. Adrenergic receptors, particularly beta-1 and beta-2 receptors, play a key role in the ventricular myocardial stress response, both acute and chronic. Variation in genetic background, particularly differences in beta-adrenergic receptors, may contribute to altered susceptibility for heart failure. Furthermore, assessment of hemodynamic factors contributing to functional decline in Fontan patients has been a problem because of inadequate imaging techniques. With magnetic resonance imaging, these factors can be assessed more adequately and non-invasively. Danielle Robbers wants to 1) assess the number of patients with clinical signs of heart failure; 2) determine the number of patients with signs of activation and/or failure of circulatory compensatory mechanisms; and 3) correlate these findings to genetic as well as hemodynamic and procedural factors that modify cardiac performance, during follow-up after the Fontan operation. |
