As illustrated in the electrocardiogram below, right bundle branch block presents with delayed activation of the right ventricle, leading to a wide QRS complex lasting greater than 0.12 seconds. Altered terminal QRS forces produce a terminal R wave in lead aVR and terminal S waves in leads I, aVL, V5 and V6. Triphasic complexes are identified as the late intrinsicoid "m-shaped" RSR' complex in lead V1, and the early intrinsicoid qRS complex in lead V6.