The Resynchronization Effect in Left Bundle Branch Pacing Can be Evaluated Non-Invasively With the Implementation of...

Area of Science:

• Cardiology
• Electrophysiology
• Medical Devices

Background:

• Left bundle branch area pacing (LBBAP) is an evolving technique for cardiac resynchronization therapy (CRT).
• Incomplete resynchronization may necessitate an additional left ventricular (LV) lead.
• A simple, non-invasive method to assess persistent posterolateral LV delay during LBBAP is needed.

Purpose of the Study:

• To evaluate if lead V8 can serve as a non-invasive marker for persistent posterolateral LV delay during LBBAP.
• To compare the efficacy of V8 lead measurements with existing methods (V6 and RWPT).

Main Methods:

• A prospective study included consecutive patients undergoing LOT-CRT implantation.
• Standard 12-lead ECGs were recorded with the V5 electrode repositioned to V8.
• Local activation time, measured as negative derivative activation time (NDAT), was compared to LV electrical delay (LVED) from the LV lead.

Main Results:

• A strong correlation was observed between NDAT-V8 and LVED during intrinsic conduction (r=0.95) and across all LBBAP subtypes (combined r=0.922).
• NDAT-V8 showed a mean difference of 2.5 ± 8 ms compared to LVED.
• Correlations were significantly weaker for NDAT-V6 and RWPT in V6/V8.

Conclusions:

• NDAT-V8 is a reliable non-invasive surrogate for LV posterolateral wall delay during LBBAP.
• NDAT-V8 outperforms NDAT-V6 and RWPT in assessing LV delay.
• NDAT-V8 shows promise as a tool to guide adequate resynchronization in LBBAP.