electrophysiology
Last reviewed 01/2018
There is no conduction down the right bundle branch. However, the septum is depolarized from the left side as usual causing an R wave in the right ventricular lead (V1) and a small Q in the left ventricular lead (V6). Excitation only spreads on its normal pathway to the left ventricle and this causes an S in V1 and an R in V6. There is delayed excitation of the right ventricle and therefore this depolarizes after the left. This causes a second R wave in V1, and a wide S wave in V6.