Which initial assessment is crucial in suspected myocardial infarction?

• A. Chest X-ray
• B. Serum potassium
• C. ECG
• D. Echocardiogram

Answer: (C)

The ECG provides the fastest and most informative initial assessment in suspected myocardial infarction. It records the heart’s electrical activity in real time and can reveal patterns of ischemia or infarction, such as ST-segment elevations, depressions, T-wave changes, or new Q waves. These findings help distinguish between STEMI and NSTEMI and drive urgent treatment decisions, including immediate reperfusion therapy when STEMI is present. Because time is critical, an ECG is obtained right away and often repeated to catch evolving changes.

Other tests play important roles but aren’t first-line for diagnosis. A chest X-ray can help rule out other causes of chest pain or show complications like edema, but it doesn’t confirm MI. Serum potassium levels relate to arrhythmia risk but don’t diagnose an infarction. Echocardiography shows wall-motion and functional abnormalities and is valuable for assessing damage after stabilization, not for the rapid initial diagnosis.