Final answer:
In leads II, III, and aVF, ST segment changes and T wave alterations signal acute myocardial infarction and myocardial ischemia of the heart’s inferior surface.
Step-by-step explanation:
When analyzing an ECG, two important changes to look for in leads II, III, and aVF are the ST segment elevation and T wave alterations. The presence of ST elevation in these leads suggests that an acute myocardial infarction (MI) is occurring, with the affected surface being the inferior wall of the heart. The changes in the T wave, which include becoming flatter or inverted, might indicate myocardial ischemia, representing one of the earlier stages of the ischemic cascade. The lead II potential, specifically, provides a valuable representation of heart-muscle function and reflects changes in electrical activity associated with depolarization and repolarization of the heart's ventricles. The inferior wall is primarily supplied by the right coronary artery, hinting toward the specific location of the blockage or pathology when these ECG changes are present.