What is the purpose of using nitroglycerin for angina relief?

The primary purpose of using nitroglycerin for angina relief is to increase blood flow to the heart muscle. Nitroglycerin is a nitrate that dilates blood vessels, particularly veins, which reduces the amount of blood returning to the heart (preload). This effect can lower both the workload on the heart and the oxygen demand, effectively alleviating the symptoms of angina. By improving blood flow, nitroglycerin helps to supply oxygen to the heart muscle, providing relief from the pain associated with angina.

In addition to increasing blood flow, nitroglycerin also causes some degree of arterial dilation, particularly in large arteries, but its significant impact on venous return plays a more critical role in the management of angina. Therefore, while increasing blood flow is integral to its function, the mechanism by which nitroglycerin alleviates angina primarily involves both decreasing myocardial oxygen demand and improving coronary blood flow.