Medicine ECG of a patient had ST segment elevation in VI-V6, lead I and aVL. Which of the following branches is involved? A Left main coronary artery B Left anterior descending C Diagonal 1 branch of LAD D Septal branch of LAD 💡 Explanation ECG of a patient had ST segment elevation in VI-V6, lead I and aVL. Which of the following branches is involved? ✓ Correct Answer: A. Left main coronary artery