Conference Proceeding - Restricted Access
Journal of the American College of Cardiology
Patients with cardiac sarcoid and high degree AV block require consideration of physiologic pacing for long-term synchrony. Left bundle branch area pacing (LBBA) is used as a bail-out strategy for failed cardiac resynchronization therapy (CRT). Fusion optimization intervals (FOI) in CRT has shown up to 10% QRS duration reduction with improvement in echocardiographic parameters.
A 68-year-old female with extracardiac sarcoidosis presented with complete heart block (figure 1A). A cardiac MRI was suggestive of cardiac sarcoidosis with delayed enhancement imaging and evidence of late gadolinium enhancement (LGE) within the mid myocardium of the basal septum and anterolateral wall.
Due to the degree of LGE and anticipated high burden of pacing, CRT-D was planned. During the procedure there was difficulty in cannulating the coronary sinus and therefore LBBA was performed by placing a LV lead in the mid-RV septum to avoid the LGE areas. Post-procedurally the rhythm was ventricularly paced with QRS duration of 180 ms (figure 1B). There was concern for pacinginduced dysynchrony given the duration of the QRS. Device interrogation continued to show RBBB with intermittent heart block (Figure 1C). FOI was fine-tuned by extending AV pacing and sensing delays producing reliable fusion of LB area pacing with conducted complexes resulting in a fused QRS duration of 128 ms (Figure 1D).
To our knowledge, this is the first report of FOI in LBBA with 30% reduction in QRS duration.
Mando R, Williamson BD, Mehta N. Programming to optimize QRS duration in left bundle area pacing for sarcoid heart block. J Am Coll Cardiol. 2022 Mar 8;79(9 Suppl):2464. doi:10.1016/S0735-1097(22)03455-6.