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

Nitroglycerin is primarily used in the management of angina pectoris due to its properties that lead to both coronary artery dilation and peripheral venous dilation. When administered, nitroglycerin is converted to nitric oxide in the body, which causes relaxation of the smooth muscle in the blood vessel walls.

Dilation of the coronary arteries increases blood flow to the heart muscle, which helps relieve the pain and discomfort of angina caused by insufficient blood flow, especially during periods of increased oxygen demand, such as exercise or stress. Additionally, peripheral venous dilation reduces the return of blood to the heart, lowering the heart’s workload and oxygen demand. Together, these actions effectively alleviate the symptoms of angina by enhancing oxygen supply while simultaneously decreasing the heart's oxygen requirements.

In contrast, the other choices do not accurately depict the pharmacological effects of nitroglycerin. While coronary artery constriction is not relevant, peripheral arterial dilation does occur but is not the primary mechanism in angina management. Decreased heart rate is not an action directly associated with nitroglycerin; rather, its primary effects relate to vasodilation. Thus, the combination of coronary artery dilation and peripheral venous dilation serves as the fundamental rationale for the use of