The Q waves should be assessed and their significance determined, particularly in regard to the diagnosis of myocardial infarction. Small Q waves are commonly a normal finding in the inferior leads III and aVF, and in the anterolateral leads aVL, I, V5 and V6. Q waves of 0.04 seconds (1 mm) duration and greater than one third the R wave's amplitude in the same lead may be pathological.

The pathological Q waves seen in V1 - V6 indicate that this patient has had an anterior MI in the past. This patient also has evidence of an acute inferior MI as shown by the ST segment elevation in leads III and aVF.