Reversibility of coronary endothelial vasomotor dysfunction in idiopathic dilated cardiomyopathy: acute effects of vitamin C.

Richartz BM, Werner GS, Ferrari M, et al.

Am J Cardiol. 2001 Nov 1; 88(9):1001-5.

In patients with idiopathic dilated cardiomyopathy, endothelium vasomotor function is disturbed. Increased oxidative stress and the consecutive formation of oxygen free radicals have been implicated as one possibility for this observation, suggesting that nitric oxide (NO) is inactivated by oxygen free radicals. We tested the hypothesis that the antioxidant, vitamin C, may improve endothelial function in idiopathic dilated cardiomyopathy. In 11 patients, the endothelium-dependent vasomotor response of the left anterior descending coronary artery to intracoronary acetylcholine (ACh) infusion (1/2 x 10(-6) mol/L, 1/4 x 10(-5) mol/L; respectively) was determined before and immediately after intravenous infusion of 3 g of vitamin C. Coronary cross-sectional diameter was obtained by quantitative coronary angiography, average peak velocity was measured by an intracoronary Doppler flow wire, and coronary blood flow (CBF) was calculated. Maximum cross-sectional diameter was determined after administration of nitroglycerin. Dose-dependent ACh showed a decrease in cross-sectional diameter (-5% to -7%, p <0 -2="-2" .05=".05" 41="41" 82="82" a="a" administration="administration" after="after" an="an" and="and" average="average" c="c" cardiomyopathy="cardiomyopathy" cbf="cbf" cross-sectional="cross-sectional" diameter="diameter" dilated="dilated" dose-dependent="dose-dependent" dysfunction="dysfunction" endothelial="endothelial" endothelium-dependent="endothelium-dependent" from="from" had="had" idiopathic="idiopathic" in="in" increase="increase" increased="increased" infusion="infusion" manner="manner" of="of" p="p" patients="patients" peak="peak" respectively="respectively" reversed="reversed" the="the" thus="thus" to="to" unchanged="unchanged" velocity="velocity" vitamin="vitamin" was="was" with="with">