Final answer:
An ECG can indicate myocardial infarction in various regions of the heart, each supplied by different coronary arteries. Elevation in anterior leads suggests LAD involvement, lateral lead changes implicate the left circumflex artery, and elevations in inferior leads typically point to RCA occlusion.
Step-by-step explanation:
Understanding Coronary Artery Territories on an ECG
When interpreting an ECG (electrocardiogram), specific patterns of elevation in the chest leads can indicate myocardial infarction (MI) in particular regions of the heart, which are supplied by different coronary arteries. Elevation in leads V1 to V4 suggests an anterior MI, typically associated with occlusion of the left anterior descending artery (LAD). The LAD follows the anterior interventricular sulcus and supplies the front part of the heart. If the amplitude in lead aVR is equal to or exceeds that in V1, this may indicate a more severe condition, such as left main coronary artery (LMCA) involvement.
When ECG shows changes in leads V5, V6, I, and aVL, the left circumflex artery, which is a branch of the left coronary artery and follows the coronary sulcus, may be implicated. This usually indicates a lateral MI. Lastly, elevations in leads II, III, and aVF are associated with inferior MI, which is often due to right coronary artery (RCA) occlusion. The RCA supplies the right side and bottom parts of the heart. The myocardial territory affected can provide insight into the particular coronary artery that may be involved in the ischemic event.