Which statement is true about nitrates in stable angina?

• A. They are used to relieve angina by venodilation reducing preload
• B. They primarily reduce mortality in stable angina
• C. They decrease heart rate
• D. They increase afterload

Answer: (A)

Nitrates relieve angina mainly through venodilation, which reduces venous return to the heart (preload). Lower preload decreases left ventricular end-diastolic pressure and wall tension, lowering myocardial oxygen demand and easing anginal symptoms. They are used for symptom relief rather than to improve survival in stable angina, so they don’t primarily reduce mortality. Nitrates can cause reflex tachycardia via blood pressure drop, so heart rate may stay the same or increase rather than decrease. They don’t increase afterload; any reduction in afterload would come from arterial dilation at higher doses, but the predominant effect is venodilation reducing preload.