Nitroglycerin's hemodynamic effect in ACS is due to dilation of which vessels?

Nitroglycerin's hemodynamic effect in ACS is due to dilation of which vessels?

• A. Arteries only
• B. Veins only
• C. Both arteries and veins
• D. Capillaries

Answer: (C)

Nitroglycerin works by releasing nitric oxide to relax smooth muscle, and its hemodynamic effect in ACS comes from dilating both veins and arteries. At typical therapeutic doses, venodilation lowers venous return to the heart (preload), which reduces LV end-diastolic pressure and wall stress, decreasing myocardial oxygen demand. At higher doses, arterial dilation reduces systemic vascular resistance (afterload), further lowering oxygen consumption. Together, these effects improve the balance between oxygen supply and demand and help relieve ischemia. Capillaries aren’t the primary target of this mechanism, so the key impact comes from dilation of both veins and arteries.

Nitroglycerin works by releasing nitric oxide to relax smooth muscle, and its hemodynamic effect in ACS comes from dilating both veins and arteries. At typical therapeutic doses, venodilation lowers venous return to the heart (preload), which reduces LV end-diastolic pressure and wall stress, decreasing myocardial oxygen demand. At higher doses, arterial dilation reduces systemic vascular resistance (afterload), further lowering oxygen consumption. Together, these effects improve the balance between oxygen supply and demand and help relieve ischemia. Capillaries aren’t the primary target of this mechanism, so the key impact comes from dilation of both veins and arteries.