Abstract P040: Muscle Metaboreflex Regulation of Arterial Blood Pressure in Children with Congenital Heart Defects

Introduction: Metabolically sensitive afferent fibers in skeletal muscle can signal an increase the sympathetic control of arterial blood pressure during exercise. This process, called the muscle metaboreflex, is augmented in adults with cardiovascular disease and contributes to exercise intolerance. The role of the muscle metaboreflex on blood pressure control in children with congenital heart defects (CHD) is not known. Hypothesis: We tested the hypothesis that the mean arterial pressure (MAP) response to the muscle metaboreflex would be augmented in children with CHD compared to healthy controls. Methods: Twenty-six children with CHD (11±2 years; males=14; females=12) and 21 age- and sex-matched controls (11±3 years; males=10; females=11) were studied. CHD diagnoses included Tetralogy of Fallot (n=7), pulmonary or aortic stenosis (n=3), hypoplastic left or right heart syndrome (n=5), Ebstien’s anomaly (n=1), atrial or ventricular septal defect (n=5), transposition of the great arteries (n=2), double in...