Is non-Q-wave infarction an ECG diagnosis?

The short answer is no! For positive diagnosis of non-Q-wave infarction, confirmatory evidence (such as elevated cardiac muscle enzyme levels) must accompany these highly suspicious ECG findings. Q waves have long been recognized as a hallmark in transmural infarct, but experience shows that using that criterion alone will result in missing a large number of acute infarctions. It is also true that occasionally Q waves will be recorded in nontransmural infarcts. The ECG changes that occur with non-Q-wave infarctions are those involving the ST segment and T waves. Both ST-segment elevation and depression may be recorded, although depression numerically outnumbers elevation. A particularly striking ECG finding, and one that should raise a high level of suspicion for infarction, is the exceedingly deep symmetric inversion of the precordial T waves. Indeed, the presence of ST segment depression and the above T-wave changes is almost always a result of nontransmural infarction. It is clinically important to diagnose non-Q-wave infarction accurately since this subset of patients has a high risk of further ischemic events.


Is non-Q-wave infarction an ECG diagnosis?_10.jpgIs non-Q-wave infarction an ECG diagnosis?_14.jpg

Leave a Reply