What is the main therapeutic action of nitroglycerin in the context of angina?

The primary therapeutic action of nitroglycerin in the context of angina is to relax coronary arteries. Nitroglycerin is a vasodilator, which means it helps to widen blood vessels. By doing so, it increases blood flow to the heart muscle itself, enhancing oxygen delivery and alleviating the ischemic pain associated with angina. This action is particularly important during an angina attack, where the heart muscle experiences insufficient oxygen due to narrowed or obstructed coronary arteries.

The relaxation of the coronary arteries also helps reduce the workload on the heart, which can contribute to a decrease in angina symptoms. While nitroglycerin may also indirectly reduce blood pressure and influence heart rate, these are not its main therapeutic actions in the management of angina. The focus is primarily on its ability to improve coronary blood flow by causing vasodilation, which is crucial in managing and relieving the symptoms of angina.