Case 2:
A 72 years old man was referred for the management of permanent atrial
fibrillation with uncontrolled ventricular rates and LV dysfunction.
Echocardiography showed moderate mitral regurgitation with LV ejection
fraction of 32%. Atrioventricular junction (AVJ) ablation with
physiological pacing option was recommended. LBBP was attempted as
previously described. PVCs of changing morphology were noted while
placing the lead deep inside the septum. Rotation was stopped
immediately after observing PVC (VES2) with narrow QRS duration and qR
in lead V1 (Figure 2A). Non-selective to selective capture of LBB could
be demonstrated at near threshold output (Figure 2D). LBB paced QRS
mimicked VES2 with duration of 124ms and pLVAT of 65ms (Figure 2B). The
pacing threshold was 0.6V/0.5ms and lead impedance of 730 ohms. LBB
potential was recorded on the LBBP lead electrogram (LBB-ventricular
interval of 25ms, Figure 2C). AVJ ablation was completed using an
irrigated-tip ablation catheter.