In ACS MONA therapy, under which condition is nitroglycerin contraindicated?

• A. Hypotension
• B. Pulmonary edema
• C. Non-ischemic chest pain
• D. Hyperkalemia

Answer: (A)

Nitroglycerin in ACS is used to relieve chest pain by dilating veins and arteries, which lowers preload and myocardial oxygen demand. However, it is contraindicated when blood pressure is too low because further vasodilation can cause a dangerous drop in perfusion to vital organs. This is especially important if there’s right-sided heart involvement, where keeping preload up is essential for maintaining cardiac output. The other scenarios don’t carry this absolute safety concern: nitroglycerin can still be used to reduce preload in pulmonary edema, isn’t inherently contraindicated for non-ischemic chest pain, and does not address hyperkalemia.