In which kind of myocardial infarction should nitroglycerin be avoided?

Nitroglycerin is a vasodilator commonly used in the management of chest pain and myocardial infarction (MI). However, it should be used with caution and is sometimes contraindicated in certain specific types of MI.

In inferior MIs, particularly those associated with right ventricular involvement, the use of nitroglycerin can lead to significant hypotension. This occurs because nitroglycerin reduces preload by dilating peripheral veins, which can decrease the filling pressure of the heart. An inferior MI often originates from occlusion of the right coronary artery (RCA) and can compromise cardiac output if the right ventricle is also affected. If the right ventricle is ischemic and unable to pump effectively, the additional volume reduction caused by nitroglycerin might precipitate severe hypotension due to decreased venous return.

Therefore, in the context of an inferior myocardial infarction, especially when there are concerns for right ventricular involvement, nitroglycerin should be avoided to prevent exacerbating hypotension and potential collapse of cardiac function. Recognizing this specific contraindication helps clinicians decide on the safe and effective management of patients experiencing different types of myocardial infarctions.