Monitoring nitroglycerin for therapeutic effects. Which finding indicates effectiveness?

• A. Blood pressure 120/80 mm Hg
• B. Heart rate 70 beats per minute
• C. ECG without evidence of ST changes
• D. Client stating that pain is 0 out of 10

Answer: (D)

Relief of chest pain is the clearest sign that nitroglycerin is working. Nitroglycerin causes venous dilation, which lowers preload and the heart’s oxygen demand; at higher doses it can also reduce afterload. When this reduces ischemia, the patient’s angina pain should improve, ideally to zero. While blood pressure and heart rate can change with nitroglycerin, those changes don’t by themselves prove the angina is relieved. An ECG might show improvement in ischemic changes, but symptom relief—no chest pain—is the most direct indicator that the medication is effective. If pain persists after nitrates, reassess for ongoing ischemia and follow appropriate emergency protocols.