Discontinuing Nitroglycerin for Cardiac Ischemia

There is an old memo from 2022 that states when giving nitro for cardiac ischemia it is acceptable to discontinue nitro when symptoms are fully resolved. Is this still the direction we are to follow? There seems to be some confusion around that and maybe some mixed understandings of what has been directed since that 2022 memo was released.

Thank you for your question about nitroglycerin use in cardiac ischemia. Nitroglycerin is a useful tool in managing suspected cardiac ischemia, but it needs careful monitoring. It works mainly as a smooth muscle relaxant: venodilation (preload reduction) arterial dilation (afterload reduction) coronary artery vasodilation Together these lower myocardial oxygen demand and improve coronary blood flow, which relieves ischemic symptoms. It is important to note that it treats symptoms but does not have a mortality benefit. When given sublingually the onset peaks by 5 minutes and its effects last for about 25 minutes. When to stop nitroglycerin Do not give further doses if any of the following apply: The patient no longer meets the directive’s conditions: HR 60–159 bpm, SBP ≥ 100 mmHg, unaltered LOA. SBP drops by one-third or more of its initial value after nitroglycerin. The 12-lead ECG is compatible with a right ventricular MI. Perform V4R on all inferior STEMIs. The patient has a severe adverse reaction. You have reached the maximum number of doses: 6, or 3 if STEMI. All signs and symptoms of ischemia have fully resolved. Look beyond chest discomfort Chest discomfort is the classic sign, but ischemia often shows up in other ways: dyspnea diaphoresis GI symptoms: nausea, vomiting, or indigestion that does not resolve neurological or systemic signs: weakness, fatigue, dizziness, or syncope profound anxiety or a sense of impending doom If a patient’s chest discomfort resolves but they’re still short of breath, diaphoretic or nauseated, the ischemia may not have resolved. If they still meet the directive’s parameters, keep treating. If you stop or withhold nitroglycerin, make sure all signs and symptoms of ischemia have resolved, and document your reasoning on the ACR. If symptoms come back, you may resume nitroglycerin as long as the patient still meets all conditions, no contraindication applies, and you stay within the maximum number of doses. Resolution of symptoms does not rule out ACS or STEMI. Continue with ASA, serial 12-leads, and appropriate transport.