in different leads

Last reviewed 07/2023

The Q waves that are considered are pathological, ie greater than one small square across and/or more than 2mm deep. Such Q waves are indicative of a myocardial infarction.

  • Q waves in V3 and V4 are indicative of an infarction of the anterior wall of the left ventricle
  • Q waves in V3 and V4 - looking at the anterior heart - and I, V2 and V5-6 - looking at the lateral surfaces of the heart - are indicative of an infarction of the anterolateral heart
  • Q waves in III and VF are indicative of an infarction of the inferior heart

Note, the presence of a Q wave does not give any indication of the age of the infarction. Once a Q wave has developed then it is usually permanent.