The pattern of QRS waves in the ECG of incomplete right bundle branch block is similar to that of complete right bundle branch block, with the main features of the ECG being a rsR’, rsr’, rSR’ or M pattern in the right thoracic leads V1 and V2, with the R ‘ waves are more often higher than r waves; leads V5-6 show qRs or Rs patterns; lead I has a significantly widened S wave and lead avR has a wide R wave; the T wave is in the opposite direction to the main wave of the QRS wave; and the QRS electrical axis is mildly right-skewed.
In addition, its main characteristic compared to complete right bundle branch block is that its QRS wave time is <0.12s, which can persist or occur intermittently, and when it does occur intermittently it has a certain regularity, possibly related to the rapidity of its heart rate.