Table 3: Diagnostic criteria for complete left bundle branch block.

1.

QRS duration greater p95 or greater than 100 ms in children 4 to 16 years of age, and greater than 90 ms in children less than 4 years of age.

2.

Broad notched or slurred R wave in leads I, aVL, V5 and V6 and an occasional RS pattern in V5 and V6 attributed to displaced transition of QRS complex.

3.

Absent q waves in leads I, V5 and V6, but in the lead aVL, a narrow q wave may be present in the absence of myocardial pathology.

4.

R peak time greater than 60 ms in leads V5 and V6, but normal in leads V1-3, when small initial r waves can be discerned in the above leads.

5.

ST and T waves usually opposite in direction to QRS.