Cardiovascular Implantable Electronic Devices -> Leads & Electrodes: -> Technology D-PO04 - Poster Session IV (ID 15) Poster

D-PO04-113 - Clinically Relevant Models Of Left Bundle Branch Block: A Test Bed For Developing Novel Pacing Lead Technology (ID 1196)


Background: Left Bundle (LB) pacing for Left Bundle Branch Block (LBBB) is becoming a favored pacing strategy. Recently, LBBB has been attributed to different levels of block. Creation and characterization of contemporary ideas on LBBB has not been attempted, evaluated and has implications for developing LBBB pacing electrodes and electronics.
Objective: In this study we attempted to create and characterize 3 different types of conduction abnormality that mimic LBBB based on contemporary concepts.
Methods: Sheep LB were used for model creation. The 3 types of conduction block that mimic LBBB were: total block (TB), partial block (PB) and LB block at distal Purkinje-muscle junction (PMJ). LB and underlying muscle were paced with bipolar pacing. TB was created by superficially cutting the LB. PB was created by superficially cutting part of the LB. PMJ block was created by slightly cooling the LB with a needle underneath the conductive tissue. A custom mapping system was used to collect electrograms.
Results: With a total of 18 LB preparations (prep), 5 had TB, 5 had PB and 8 had distal PMJ block. 5/5 TB preps had no activity distal to the block. 4/5 PB preps had significantly delayed activity (>20ms). 7/8 of reversible PMJ block preps had delayed or no activity during cooling and normal activity after cooling. All 3 block types had a success rate of 89%. TB can be identified by a lack of activity distal to the block. PB can be identified by a delay in activity distal to the block.
Conclusion: We have created an experimental model in LB prep and characterized 3 types of block that mimic mechanisms of LBBB. This provides insight in differentiating LBBB types in patients and to devise LB pacing electrodes and electronics.