Case series
A total of 22 patients underwent LBBP using the EIS catheter in National
Heart Centre Singapore between May 2021 and October 2021. These included
21 pacemakers (4 patients with symptomatic sinus node dysfunction, 6
Tachy-Brady syndrome, 11 patients with high grade AV nodal conduction
disease), and 1 cardiac resynchronization therapy devices. The mean age
of patients were 71.7 years and 16 (72.7%) were males. Baseline patient
characteristics are shown in Table 1.
A total of 19 (86%) LBBP was successfully performed out of 22 patients.
There were 3 unsuccessful LBBP attempts:
- Patient 8 is a 75-year-old male with ischemic cardiomyopathy and left
bundle branch block (LBBB) on baseline ECG. Attempts at LBBP in
multiple positions did not result in a satisfactory narrowing of the
QRS, suggesting that the conduction delay likely occurred distal to
the septal LBB. An Abbott QuartetTMQuadripolar Traditional S-shape 86 cm coronary sinus lead was
positioned in the lateral branch of the coronary sinus. Biventricular
(BiV) pacing with SyncAV programmed on, resulted in a BiV paced QRS of
103 ms.
- Patient 15 is a 74-year-old female with symptomatic complete heart
block (CHB). There was initial successful LBBP implantation with a
non-selective LBBP QRS of 115 ms. Lead dislodgement occurred within 24
hours, necessitating lead revision and conversion to a conventional RV
mid-septum pacing lead position.
- Patient 20 is a 79-year-old female with symptomatic tachy-brady
syndrome. Repeated initial attempts at LBBP yielded
unacceptably high pacing thresholds (the patient was on a Vaughan
William Class 1C agent for rhythm control). The final position with
acceptable pacing and sensing threshold likely captured only the left
ventricular septum (paced QRS 130 ms, at both high and low outputs).