What are the actions of nitroglycerin in the management of angina?

Nitroglycerin is primarily used in the management of angina due to its ability to dilate both arteries and veins. This vasodilation leads to a decrease in the workload of the heart. When veins are dilated, there is a reduction in venous return (preload), which lessens the amount of blood the heart has to pump. Likewise, the dilation of arteries (afterload) reduces the resistance against which the heart must work during contraction. As a result, nitroglycerin alleviates angina symptoms by improving blood flow to the heart muscle while simultaneously decreasing the heart's oxygen demand. This dual action makes it an effective treatment in managing angina episodes.