Case 4:
A 73 years old woman with normal LV function presented with symptomatic
complete heart block. LBBP was done using 3830
Selectsecuretm lead and C315His sheath. The pacing
lead was positioned deep inside the septum by 4-5 rapid turns. PVCs with
changing morphology were noted during lead advancement. Lead rotation
was stopped immediately after observing narrow complex PVC (VES4) with
qR pattern in lead V1 (figure 4A). Electrograms from the pacing lead
demonstrated sharp left bundle potential (Figure 4C) preceding the
ventricular electrogram (LB-ventricular interval of 20ms). Pacing
threshold was 0.4V at 0.5ms and lead impedance was 680 ohms. The paced
QRS morphology mimicked the narrow PVC morphology (VES4) with QRS
duration of 114ms with pLVAT in lead V5 of 70ms (Figure 4B). RBB delay
was corrected by optimizing pacing output to allow anodal capture
(Figure 4D)