In Acute Myocardial Infarction (AMI), the priority nursing assessment is continuous cardiac monitoring and 12-lead ECG because:

• AMI causes life-threatening arrhythmias (ventricular fibrillation, ventricular tachycardia) in the first hours
• ECG identifies the infarct location, extent, and guides reperfusion decisions
• Time-to-treatment (door-to-balloon time ≤ 90 minutes for STEMI) is the key determinant of outcomes

The 4 Ts of AMI nursing priority:

1. Time (ECG within 10 minutes)
2. Thrombolytics/PCI preparation
3. Therapy (MONA: Morphine, Oxygen, Nitrates, Aspirin)
4. Telemetry (continuous cardiac monitoring)

Cardiac biomarkers (Troponin I/T) are diagnostic but take time. ECG provides immediate actionable information.