Significant Q waves indicate?

Significant Q waves indicate?

• A. Myocardial ischemia
• B. Myocardial injury
• C. Heart failure
• D. Myocardial infarction

Answer: (D)

Significant Q waves on an ECG indicate myocardial infarction, specifically implying transmural necrosis with scar formation. They form when a portion of the heart muscle has died and no longer conducts depolarization, creating a deep, wide Q wave in the affected leads. These Q waves tend to persist after the acute event, signaling a past infarct rather than ongoing ischemia. Ischemia typically shows ST-segment depression or T-wave changes without lasting deep Q waves, and acute injury presents with ST elevation. Heart failure can produce various ECG changes but not the diagnostic, persistent Q waves associated with infarction.

Significant Q waves on an ECG indicate myocardial infarction, specifically implying transmural necrosis with scar formation. They form when a portion of the heart muscle has died and no longer conducts depolarization, creating a deep, wide Q wave in the affected leads. These Q waves tend to persist after the acute event, signaling a past infarct rather than ongoing ischemia. Ischemia typically shows ST-segment depression or T-wave changes without lasting deep Q waves, and acute injury presents with ST elevation. Heart failure can produce various ECG changes but not the diagnostic, persistent Q waves associated with infarction.