Which medication prescription is known to decrease both preload and afterload in a client with acute myocardial infarction?

Nitroglycerin is a medication that effectively decreases both preload and afterload, particularly in the context of an acute myocardial infarction. Preload refers to the volume of blood in the ventricles at the end of diastole, while afterload is the resistance the heart must overcome to eject blood during systole.

Nitroglycerin works as a vasodilator, primarily by relaxing the smooth muscles in the blood vessels. When it is administered, it leads to the dilation of veins (which decreases preload) as well as arteries (which reduces afterload). By lowering preload, nitroglycerin helps to reduce the workload on the heart and decrease the oxygen demand, which is crucial during a myocardial infarction. Additionally, the reduction of afterload allows the heart to pump blood more easily, improving cardiac output and relieving stress on the heart muscle.

In contrast, other medications listed serve different purposes. Propranolol, as a beta-blocker, primarily reduces heart rate and myocardial oxygen demand rather than directly affecting preload and afterload. Morphine, while it can provide pain relief and mild vasodilation, does not specifically target preload and afterload reduction to the extent that nitroglycerin does. Captopril, an ACE inhibitor