On the relationship between Q waves in leads II and VF and inferior-posterior wall motion abnormalities

Twelve electrocardiographic criteria, based on various combinations of Q wave morphology in leads II and aVF, were tested in 235 cases for their diagnostic value in detecting inferoposterior wall motion abnormality (presumably reflecting infarction in the area) as demonstrated on left ventriculogram. The most reliable indicator of inferoposterior wall motion abnormality was found to to a QR complex with a Q wave width greater than or equal to .03 or greater than or equal to .04 sec associated with a Q/R ratio greater than .25. Using as criterion a QR complex with a Q wave width greater than or equal to .04 sec and a Q/R ratio greater than .25, the sensitivity was 41.9% in the cases with akinetic-dyskinetic wall motion and 3.7% in the cases with hypokinesis with an associated specificity of 100%. By lowering the Q wave duration to greater than or equal to .03 sec, the sensitivity increased to 51.6% and 9.3%, respectively, while retaining a very high specificity (96%). The exclusion of cases with a Q and R of less than 5 mm markedly lowered the sensitivity with a negligible increase in specificity. QS complexes in leads II or aVF were not found to be reliable indicators of inferoposterior wall motion abnormality.