Question

ecg changes from ischemia to injury to infraction

Answer 1

In ischemia the best variation can be seen in the ST segment. The ST segment that stays in isoelectric point. It's the state between ventricular depolarization and repolarization. so ischemia cause abnormality in the isoelectric point and it shows a depression. Now the ST segment seems to be depressed.

In myocardial injury we can see changes in the ST segment that it is elevated and the ST segment is reaching height of T wave. The wave tallness is increased because of abnormal ventricular repolarization in some cases symmetrical inversion of T waves can be seen.

In the case of infarction we can see sharp raise in the ST segment. The inversion of the T wave is common. Then we can see pathologic Q waves that shows the necrosis. Thus we can understand the condition from these ECG variations.