Pharmacologic mechanisms of nitrates in myocardial ischemia

Nitrates exert both hemodynamic and nonhemodynamic effects that help explain the mechanisms by which these drugs benefit patients with myocardial ischemia. The hemodynamic effects of nitrates include relaxation of conduit arteries, increased arterial compliance, increased venous capacitance, dilation of collateral vessels in the myocardium, and, possibly, increased myocardial compliance. A growing body of evidence suggests that the nonhemodynamic effects of these agents include inhibition of vascular smooth muscle growth and of myocyte hypertrophy and ventricular remodeling. Since endothelial function appears to be abnormal in patients with myocardial ischemia and nitrates replicate many of the effects of endothelium-derived relaxing factor, these drugs may be viewed as a pharmacologic replacement for deficient endogenous activity.