Two apparently remote types of ventricular tachycardia from a single right bundle branch focal source

Figures

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  Figure 1. A: Type 1 and B: type 2 of ventricular tachycardia on 12-lead surface electrocardiogram.

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  Figure 2. Electroanatomic activation mapping of the right ventricle in left anterior oblique view (C) during type 2 ventricular tachycardia (VT) (E) showed the VT origin in the distal right bundle branch (RBB) region close to the septal insertion of moderator band (the earliest right ventricular activation is coded in red color; the course of His bundle [HB] and RBB is marked by yellow dots). Pace mapping directly beneath (C, lower arrow) and above (C,upper arrow) the moderator band insertion produced favorable match between the paced QRS complex (B, D) and the QRS complex of type 1 (A) or type 2 (E) VT, respectively. F: The course of the moderator band (yellow arrows) and ablation catheter (white arrows) on intracardiac echocardiography.

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  Figure 3. Ventricular ectopy was targeted by stepwise ablation starting anteriorly beneath the septal insertion of moderator band (A – left oblique view of right ventricular electroanatomic map) and was eventually abolished at the distal end of right bundle branch (RBB) (marked by arrow, B – left lateral view of right ventricular electroanatomic map) above and proximal to the septal insertion of moderator band at a site displaying small RBB potential (arrows) preceding the local ventricular electrogram during ectopic and sinus beat (first and second beat, C). The earliest local ventricular potential recorded by the distal bipole of ablation catheter (ABLd) preceded the onset of surface QRS complex by 23 ms (C). ABLp = recording from the proximal bipole of ablation catheter; CSp, CSd = recordings from the proximal and distal bipoles of the 10-pole catheter placed in the coronary sinus. Other abbreviations and explanations as in Figure 2.