From the Guidelines
The first step in managing someone having a heart attack is administering aspirin, as it has been proven to reduce mortality by preventing further clot formation, with a recommended dose of 162-325 mg of non-enteric coated aspirin to be chewed as soon as possible after symptoms begin, unless the person has a known aspirin allergy or active gastrointestinal bleeding 1. When a heart attack occurs, a blood clot typically blocks a coronary artery, and aspirin helps by inhibiting platelet aggregation, which prevents the clot from growing larger. While oxygen, nitroglycerin, and morphine are all important components of heart attack management, they come after aspirin in the treatment sequence. Oxygen should be administered only if the patient's oxygen saturation is low (below 90%), nitroglycerin helps dilate blood vessels to improve blood flow to the heart, and morphine may be given for pain relief and to reduce anxiety. However, the immediate priority is aspirin administration due to its proven ability to reduce mortality in heart attack patients by preventing further clot formation, as supported by the 2024 American Heart Association guidelines 1. Some key points to consider when administering aspirin include:
- The patient should chew the aspirin tablet to hasten absorption
- Aspirin should be given as soon as possible after symptoms begin
- The patient's oxygen saturation should be checked before administering oxygen, and oxygen should only be given if the saturation is below 90% 1
- Nitroglycerin and morphine may be given after aspirin, but with caution and consideration of the patient's individual needs and medical history. It's also important to note that the most recent guidelines prioritize aspirin administration as the first step in managing a heart attack, and that other treatments such as oxygen, nitroglycerin, and morphine should be given after aspirin, as supported by the highest quality and most recent evidence 1.
From the Research
First Step in Managing a Heart Attack
The first step in managing someone having a heart attack involves several key interventions. The primary goal is to restore blood flow to the heart and reduce the risk of further damage.
- Supplemental Oxygen: Administering supplemental oxygen is crucial, especially if the patient is experiencing shortness of breath or has low oxygen saturation 2.
- Aspirin Administration: Aspirin is given to prevent blood from clotting and to reduce the risk of further heart damage 3, 4.
- Nitroglycerin Administration: Nitroglycerin is used to treat chest pain and to improve blood flow to the heart 3, 5.
- Morphine Administration: Morphine may be administered to relieve pain, but its use is associated with risks such as higher mortality and increase in the size of the infarct 6.
Prioritization of Interventions
The prioritization of these interventions may vary depending on the patient's specific condition and the availability of medical resources. However, the general consensus is that supplemental oxygen, aspirin, and nitroglycerin are the initial treatments of choice for acute myocardial infarction.
- MONA Mnemonic: The traditional MONA mnemonic (morphine, oxygen, nitrates, and aspirin) is still widely used, but its relevance in contemporary practice has been questioned due to the risks associated with morphine and the availability of other evidence-based treatments 4, 6.
- Contemporary Management: A more contemporary approach to managing acute coronary syndromes is reflected in the THROMBINS2 mnemonic, which includes thienopyridines, heparin/enoxaparin, renin-angiotensin system blockers, oxygen, morphine, beta blocker, intervention, nitroglycerin, statin/salicylate 4.