In acute coronary syndrome, what is the primary purpose of nitrates given during management?

• A. Relieve chest pain by dilating veins, reducing preload, and improving myocardial oxygen supply-demand balance.
• B. Directly dissolve clots.
• C. Increase systemic vascular resistance.
• D. Replace aspirin in antiplatelet therapy.

Answer: (A)

In acute coronary syndrome, the main role of nitrates is to relieve chest pain and ischemia by venodilating the systemic veins. This reduces venous return (preload) to the heart, which lowers left ventricular end-diastolic pressure and wall stress. With the heart under less stress, its oxygen demand decreases, helping to rebalance oxygen supply and demand and relieve ischemia. Nitrates can also provide some coronary vasodilation, but their primary benefit in this setting is reducing preload rather than directly dissolving clots, increasing systemic vascular resistance, or replacing aspirin in antiplatelet therapy.