Final answer:
An ECG showing persistent ST segment elevation and deep Q waves in the same leads after an MI indicates significant heart muscle damage. ST segment elevation is a sign of acute MI, while deep Q waves may denote previous MI injury. Cardiac enzymes can also indicate myocardial damage and corroborate ECG findings.
Step-by-step explanation:
The student's question refers to the characteristics of an electrocardiogram (ECG) following a myocardial infarction (MI). Persistent ST segment elevation after a recent MI, coupled with deep Q waves in the same leads, suggests that there has been significant damage to the heart muscle. The size and duration of the Q waves, ST segment, and other components of an ECG give insight into cardiac function. ST segment elevation typically indicates an acute MI and is an important diagnostic marker, while the presence of deep Q waves can indicate a history of an MI. The fine vector analysis provided through the multiple leads of the ECG helps in precise localization of the infarcted area, and cardiac enzymes such as creatine kinase MB and cardiac troponin are useful blood markers that complement the ECG findings by indicating myocardial cell damage. A comparison of a recent ECG with older ones can reveal subtle changes in cardiac health over time