ascorbic-acid and Eisenmenger-Complex

Adults with cyanotic congenital heart disease (CCHD) have been shown to have endothelial dysfunction in the forearm resistance vessels as assessed with venous occlusion plethysmography. Whether these abnormalities are confined to the microvasculature or reflect generalized endothelial dysfunction remain unknown. We used high-resolution ultrasound to compare flow responses and endothelial-dependent flow-mediated dilation (FMD) in the brachial artery of 13 adult patients with CCHD and 14 healthy controls. High-dose vitamin C was infused to evaluate the possible role of reactive oxygen species on endothelial vasomotor function. FMD was measured both prior to and after vitamin C infusion. Sublingual glyceryl nitrate was given to assess endothelium-independent responses. FMD did not differ among patients with CCHD and controls either before (6.2 +/- 4.1, 5.1 +/- 2.6%, p = 0.44) or after (5.1 +/- 2.8, 5.2 +/- 3.1%, p = 0.90) vitamin C infusion. Endothelium-independent vasodilatation was similar in both groups (14.3 +/- 3.7, 13.2 +/- 4.4%). There were no differences in baseline flow or in measures of reactive hyperemia. Adults with CCHD appear to have preserved endothelial function in their conduit arteries. This suggests that these patients are not at an increased risk of premature atherosclerotic cardiovascular events.

Topics: Adult; Ascorbic Acid; Blood Flow Velocity; Brachial Artery; Case-Control Studies; Cyanosis; Eisenmenger Complex; Endothelium, Vascular; Female; Heart Defects, Congenital; Humans; Male; Microcirculation; Middle Aged; Nitroglycerin; Oxidative Stress; Statistics, Nonparametric; Ultrasonography

Topics: Aortic Valve Insufficiency; Ascorbic Acid; Cardiac Catheterization; Eisenmenger Complex; Electrocardiography; Electrodes; Heart Septal Defects; Heart Septal Defects, Ventricular; Heart Valve Diseases; Humans; Hydrogen; Indicator Dilution Techniques; Methods; Mitral Valve Insufficiency; Platinum; Pulmonary Valve Stenosis; Tetralogy of Fallot; Tricuspid Valve Insufficiency