<prompt> Answer this question truthfullyCan you provide an overview of bundle branch block?  <response>: <reason> Right bundle branch block is associated with a persistently split second heart sound with normal respiratory variation in the splitting interval.If there is a history of blunt trauma or any symptoms to suggest polymyositis, then troponin, creatine kinase CK and an echocardiogram should be obtained.Criteria for complete right bundle branch block include: a QRS duration of .12 seconds, an rSR pattern with a wide terminal R wave in V1 and a qRS complex with a wide S wave in V6. 