4 Myocardial Infarction
Learn to recognize possible myocardial infarction, understand urgent assessment and treatment priorities, monitor for complications, and support recovery.
Recognizing symptoms and seeking emergency care
Possible symptoms include new chest pressure, nausea, shortness of breath, or discomfort in the back, jaw, neck, arm, or stomach. Symptoms may ease and return, and they do not have to include severe chest pain.
When a heart attack is suspected, call emergency medical services (911) and arrange immediate evaluation. Do not wait for symptoms to become more typical, arrange only a routine appointment, or have the person drive to the hospital.
Assessing possible
Assessment of possible MI combines the clinical presentation, findings, and cardiac biomarkers. A nondiagnostic first or an initial that is not elevated does not, by itself, rule out MI.
Continue clinical assessment, repeat ECGs and troponin testing as indicated, and escalate care if the patient worsens. A single early result may not settle the diagnosis; continue evaluation according to the acute-care pathway.
Urgent treatment for
A patient with ongoing chest pressure and an showing ST-segment elevation consistent with acute MI needs urgent escalation. Activate the emergency pathway and prepare for urgent coronary angiography and , as indicated.
Rapid restoration of blood flow limits heart-muscle injury. Do not delay the pathway while awaiting a biomarker result. Treatment decisions depend on the patient and the services available.
Using oxygen when indicated
Assess and monitor oxygenation, but do not assume that every patient with MI needs supplemental oxygen. For a patient who is breathing comfortably, has no respiratory distress, and has an oxygen saturation of 97% on room air, continue monitoring and give oxygen only if clinically indicated, such as for hypoxemia or respiratory distress.
Use the patient’s condition and the applicable clinical protocol to guide oxygen use.
Monitoring after PCI
After PCI through the radial artery, check the access site for bleeding or hematoma. Assess the hand for color, warmth, sensation, and perfusion, and monitor the patient’s vital signs and for recurrent ischemic symptoms.
Follow the specific post-procedure instructions for the access device and site. Current acute coronary syndrome guidance emphasizes radial access to reduce bleeding and vascular complications compared with femoral access.
Recognizing serious complications
New hemodynamic instability, pulmonary edema, or a new murmur after MI can signal a life-threatening mechanical complication. Sudden hypotension and acute shortness of breath accompanied by a new loud systolic murmur require urgent escalation and diagnostic assessment; possible complications include papillary muscle rupture or ventricular septal rupture.
Do not treat these changes as expected recovery or defer assessment to a routine round.
Responding to cardiac arrest
MI can trigger a dangerous and cardiac arrest. If a patient becomes unresponsive and is not breathing normally, activate the emergency response, assess for cardiac arrest, and begin CPR and use an AED according to training and protocol.
This is an immediate emergency; do not delay the response to obtain a full medical history or offer oral fluids.
Supporting recovery after MI
Recovery commonly includes taking prescribed medicines, attending follow-up care, and participating in when referred. provides supervised exercise, education, and support.
Activity should increase according to the individual recovery plan and the care team’s guidance on activity and risk reduction. Do not stop prescribed medicines just because chest discomfort resolves, avoid all physical activity indefinitely, or return to strenuous activity without discussing it with the care team.