Systemic Endothelial Dysfunction in Adults With Cyanotic Congenital Heart Disease

Background— Secondary erythrocytosis results in increased shear stress in cyanotic congenital heart disease (CCHD), which may modify the balance between vasodilators and vasoconstrictors and affect systemic endothelial function. Because no data are available on systemic vasomotion, systemic endothelial function and nitric oxide (NO) availability were investigated in CCHD patients. Methods and Results— Responses to arterial endothelium-dependent (acetylcholine [Ach]) and -independent (sodium nitroprusside [SNP]) vasodilation, NO synthase blockade (NG-monomethyl-l-arginine [l-NMMA]), endothelin-1 (ET-1), and ET-1 receptor blockade by BQ-123 in 11 CCHD patients (O2 saturation <90%; mean±SD, 79±1%; mean±SD age, 39±2 years) were compared with those in 10 age-matched healthy referents by using forearm venous occlusion plethysmography. Resting forearm blood flow (FBF) was lower in CCHD patients than in referents (2.4±0.2 versus 3.5±0.4 mL · min−1 · 100 mL−1 of forearm volume [FAV], P<0.05). Although the response...