Figure legend:
Figure 1 . Figure 1a – 12 lead ECG showing wide QRS tachycardia of LBBB morphology. Figure 1b – 12 lead ECG showing sinus rhythm with LBBB aberrancy. Figure 1c – On pacing from RA appendage, antegrade His and HV interval of 45ms with LBBB aberrancy is seen. Figure 1d – On pacing from lateral RA, retrograde His with VH interval of 10ms and QRS of LBBB morphology is seen. Figure 1c and Figure 1d, His P – proximal bipole and His D – distal bipole of quadripolar His catheter and RVA – distal bipole of catheter in RV apex.
Figure 2. Intracardiac electrogram when septal refractory APC was given. From top to bottom – 12 leads of surface ECG, LRA – distal bipole of catheter in lateral right atrium, His P, His D and RVA as in Figure 1.
Figure 3 . Intracardiac electrogram when septal refractory APC was given. From top to bottom – I, aVF and V1 represent leads of surface ECG, LRA p – proximal bipole and LRA d - distal bipole of catheter in lateral right atrium, His P, His D and RVA as in Figure 1.