Abnormal q-wave is defined as a wave with a duration greater than 0.04 S and a depth greater than 1/4 of the R-wave in the same lead. it is divided into small q-waves, which are usually physiologic, and large q-waves, which are often pathologic and are caused by previous infarction or cardiomyopathy.
1. small q wave: this kind of q wave does not meet the diagnostic standard of pathological q wave, it may be caused by cardiac repolarization due to cardiac transposition or positional change, this kind of q wave usually does not need special treatment.
2. Large q-waves: these are the ones that meet the diagnostic criteria for pathologic q-waves.
It is usually seen in two cases: one is old myocardial infarction, after myocardial infarction, there will remain depolarization abnormality, and pathological q-wave will appear in the corresponding leads when perfecting ECG examination; another is due to cardiomyopathy, there will also be depolarization abnormality which will be shown on ECG.
When abnormal q-waves appear on ECG, it is important to consult a doctor to find out the cause of the abnormal q-waves.