WESTPORT, CT (Reuters Health) – Endothelial vasomotor dysfunction in idiopathic dilated cardiomyopathy is reversible with intravenous doses of vitamin C, German researchers report.
To prove that endothelial dysfunction may be caused, in part, by the degradation of nitric oxide (NO), Dr. Hans R. Figulla and colleagues from the Friedrich-Schiller-University Jena studied the effect of infusions of vitamin C in 11 patients with idiopathic dilated cardiomyopathy.
Before and after an intravenous infusion of vitamin C, the endothelium-dependent vasomotor response of the left anterior descending coronary artery to intracoronary acetylcholine infusion was determined.
After acetylcholine infusion there was a dose-dependent decrease in cross-sectional diameter and an increase in average peak velocity. Coronary blood flow remained unchanged, according to the report in the November 1st issue of The American Journal of Cardiology.
When vitamin C was infused there was an 11% to 15% dose-dependent increase in cross-sectional diameter, and average peak velocity increased by a minimum of 20% to a maximum of 41% (p < 0.05). Coronary blood flow also increased after vitamin C infusion from a minimum of 38% (p < 0.01) to a maximum of 82% (p < 0.001), Dr. Figulla's team reports.
"This study demonstrates that impaired endothelial function is present in idiopathic dilated cardiomyopathy and can be acutely reversed by intravenous doses of the antioxidant vitamin C," the German team notes.
"Therefore, endothelial dysfunction of the coronary arteries in patients with idiopathic dilated cardiomyopathy is not caused by NO, but by increased inactivation of NO by oxygen free radicals," they conclude.