TY - JOUR
T1 - Intramural conduction system gradients and electrogram regularity during ventricular fibrillation
AU - Tri, Jason
AU - Asirvatham, Roshini
AU - DeSimone, Christopher V.
AU - Killu, Ammar M.
AU - Sugrue, Alan M.
AU - Suddendorf, Scott H.
AU - Ladewig, Dorothy J.
AU - Kapa, Suraj
AU - Friedman, Paul A.
AU - McLeod, Christopher J.
AU - Asirvatham, Samuel J.
N1 - Publisher Copyright:
© 2018 Indian Heart Rhythm Society
PY - 2018/11/1
Y1 - 2018/11/1
N2 - Introduction: The His-Purkinje system has been shown to harbor triggers for ventricular fibrillation (VF) initiation. However, the substrate responsible for VF maintenance remains elusive. We hypothesized that standard, electrode-based, point-to-point mapping would yield meaningful insight into site-specific patterns and organization which may shed light on the critical substrate for maintenance of VF. Methods: VF was induced under general anesthesia by direct current (DC) application to the right ventricle in 7 acute canines. A standard EPT Blazer mapping catheter (Boston Scientific, Natuck, MA) was used for mapping in conjunction with a Prucka recording system. We collected 30 consecutive electrograms at 24 distinct sites, confirmed by fluoroscopy and intracardiac echo. These sites included both endocardial and epicardial locations throughout the ventricles and conduction system. Results: A total of 5040 individual data points were collected in 7 separate canine studies. During VF mapping, a transmural disparity was found between the epicardium (average cycle length [CL] of 1136 m s) and the endocardium (average CL of 123 m s) with a p value of <0.01. An additional, intramural gradient was found when comparing the proximal, insulated conduction system to the distal, non-insulated conduction system (average CL 218 versus 111 m s [p = 0.03]). Conclusion: Our data are supportive of a novel observation of intramural difference between insulated and non-insulated regions of the His-Purkinje network in canines. In addition, certain areas exhibited periods of regular electrogram characteristics; this was despite the heart remaining in terminal VF. These early canine data merit further study to investigate if specific ablation of the distal conduction system can perturb or extinguish VF.
AB - Introduction: The His-Purkinje system has been shown to harbor triggers for ventricular fibrillation (VF) initiation. However, the substrate responsible for VF maintenance remains elusive. We hypothesized that standard, electrode-based, point-to-point mapping would yield meaningful insight into site-specific patterns and organization which may shed light on the critical substrate for maintenance of VF. Methods: VF was induced under general anesthesia by direct current (DC) application to the right ventricle in 7 acute canines. A standard EPT Blazer mapping catheter (Boston Scientific, Natuck, MA) was used for mapping in conjunction with a Prucka recording system. We collected 30 consecutive electrograms at 24 distinct sites, confirmed by fluoroscopy and intracardiac echo. These sites included both endocardial and epicardial locations throughout the ventricles and conduction system. Results: A total of 5040 individual data points were collected in 7 separate canine studies. During VF mapping, a transmural disparity was found between the epicardium (average cycle length [CL] of 1136 m s) and the endocardium (average CL of 123 m s) with a p value of <0.01. An additional, intramural gradient was found when comparing the proximal, insulated conduction system to the distal, non-insulated conduction system (average CL 218 versus 111 m s [p = 0.03]). Conclusion: Our data are supportive of a novel observation of intramural difference between insulated and non-insulated regions of the His-Purkinje network in canines. In addition, certain areas exhibited periods of regular electrogram characteristics; this was despite the heart remaining in terminal VF. These early canine data merit further study to investigate if specific ablation of the distal conduction system can perturb or extinguish VF.
KW - Conduction system
KW - Endocardium
KW - Epicardium
KW - His-purkinje network
KW - Purkinje
KW - Transmural gradient
KW - Ventricular fibrillation
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U2 - 10.1016/j.ipej.2018.07.006
DO - 10.1016/j.ipej.2018.07.006
M3 - Article
AN - SCOPUS:85050378105
SN - 0972-6292
VL - 18
SP - 195
EP - 200
JO - Indian Pacing and Electrophysiology Journal
JF - Indian Pacing and Electrophysiology Journal
IS - 6
ER -