Pathologic Q wave

Abnormally deep and/or wide Q wave on ECG, typically ≥0.03-0.04 s in duration and ≥1-2 mm in depth in at least two contiguous leads, indicating electrically silent myocardium. Possible causes are prior transmural myocardial infarction, hypertrophic cardiomyopathy, left ventricular hypertrophy, cardiac amyloidosis, left bundle branch block, ECG electrode misplacement, and normal variant positional Q wave.