Table 5.

Advantages and limitations of HBP and of LBBAP

HBP	LBBAP
Advantages	Advantages
Maximum electrical synchrony Endpoints well-defined for successful His capture Extractability has been demonstrated Relatively good mid-term evidence for safety and efficacy Avoids crossing the tricuspid valve when implanted on the atrial aspect of the annulus) Some evidence of medium and long-term lead extraction115,116	Large target area Correction of more distal conduction disease Low capture thresholds Good sensing parameters Consistent back-up myocardial capture (in addition by anodal capture by the ring electrode) No requirement for back-up pacing leads AV nodal ablation without risk of compromising lead function
Disadvantages/limitations	Disadvantages/limitations
Small target area Capture thresholds may be high Sensing issues (atrial and His oversensing, ventricular undersensing) Limited to correction of proximal conduction block only Risk if distal conduction block develops over follow-up High (up to 11%97) requirement for lead revision Back-up ventricular leads may be indicated in specific situations Complex programming in case of back-up leads Risk of compromising lead function with AV node ablation32,33,117	Conduction tissue capture may be difficult to demonstrate in some cases Requirement of digital callipers (i.e. electrophysiology recording system) for measuring parameters of conduction system capture Less electrical synchrony compared to HBP, especially in patients with normal baseline QRS Complications specific to transseptal route (septal perforation, lesions to coronary vessels, septal hematoma, etc.) Tricuspid regurgitation53,62,63 May be challenging in patients with septal scar Limited (but growing) evidence for safety and efficacy Long-term extractability needs to be demonstrated