Stimulation and propagation of activation in conduction tissue: Implications for left bundle branch area pacing
Autor: | Patrick F.H. Lai, Kumaraswamy Nanthakumar, Ahmed Niri, Menashe B. Waxman, Abhishek Bhaskaran, John Asta, Arulalan Veluppillai, Stéphane Massé, Eugene Downar |
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Rok vydání: | 2020 |
Předmět: |
medicine.medical_specialty
Bundle of His Stimulation 030204 cardiovascular system & hematology 03 medical and health sciences Electrocardiography 0302 clinical medicine Cardiac Conduction System Disease Heart Rate Physiology (medical) Internal medicine Left bundle branch Medicine Animals 030212 general & internal medicine Evoked potential Lead (electronics) Endocardium Sheep business.industry Left bundle branch block Cardiac Pacing Artificial Thermal conduction medicine.disease Disease Models Animal Cardiology Electrical conduction system of the heart Cardiology and Cardiovascular Medicine business |
Zdroj: | Heart rhythm. 18(5) |
ISSN: | 1556-3871 |
Popis: | Background Characterizing wavefront generation and impulse conduction in left bundle (LB) has implications for left bundle branch area pacing (LBBAP). Objectives The purpose of this study was to describe the pacing characteristics of LB and to study the role of pacing pulse width (PW) in overcoming left bundle branch block. Methods Twenty fresh ovine heart slabs containing well-developed and easily identifiable tissues of the conduction system were used for the study. LB stimulation, activation, and propagation were studied under baseline conditions, simulated conduction slowing, conduction block, and fascicular block. Results The maximum radius of the LB early activation increased up to 13.4 ± 2.4 mm from the pacing stimulus, and the time from stimulus to evoked potential shortened when pacing PW was increased from 0.13 to 2 ms at baseline. Conduction slowing and block induced by cooling could be resolved by increasing pacing PW from 0.25 to 1.5 ms over a distance of 10 ± 1.5 mm from the pacing stimulus. The LB strength-duration (SD) curve was shifted to the left of the myocardial SD curve. Conclusion Increasing PW resolved conduction slowing and block and bypassed the experimental model of fascicular block in LB. Precise positioning of the LB lead in left ventricular subendocardium is not mandatory in LBBAP, as the SD curve of LB was shifted to the left of the myocardium SD curve and could be captured from a distance by optimizing PW. |
Databáze: | OpenAIRE |
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