What is the purpose of performing a 12-lead ECG within 10 minutes of ED arrival for patients with chest pain?

• A. To rapidly identify STEMI, localize infarct territory, and guide urgent reperfusion decisions
• B. To evaluate pulmonary function
• C. To detect electrolyte abnormalities
• D. To assess heart rate variability only

Answer: (A)

Time is myocardium. Getting a 12-lead ECG within 10 minutes for chest pain is about rapidly identifying a STEMI and starting reperfusion decisions right away. The ECG can show ST-segment elevations in specific leads that map to the heart’s regions, pointing to the infarct territory and suggesting which coronary artery is involved. That immediate information drives activation of urgent reperfusion—via PCI or thrombolysis if PCI isn’t available—because shortening door-to-reperfusion time saves myocardium and improves survival. While an ECG can reveal other issues such as arrhythmias or electrolyte disturbances, these findings don’t carry the same urgent weight for treatment as confirming STEMI and guiding reperfusion.