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Electrophysiology of the Atrio‐AV Nodal Inputs and Exits in the Normal Dog Heart
Author(s) -
HIRAO KENZO,
SCHERLAG BENJAMIN J.,
POTY HERVE,
OTOMO KENICHIRO,
TONDO CLAUDIO,
ANTZ MATTHIAS,
PATTERSON EUGENE,
JACKMAN WARREN M.,
LAZZARA RALPH
Publication year - 1997
Publication title -
journal of cardiovascular electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.193
H-Index - 138
eISSN - 1540-8167
pISSN - 1045-3873
DOI - 10.1111/j.1540-8167.1997.tb00852.x
Subject(s) - ablation , medicine , catheter ablation , cardiology , atrioventricular node , radiofrequency ablation , electrophysiology , nuclear medicine , tachycardia
Ablation of Atrionodal Connections. Introduction : We studied the effects of selective and combined ablation of the fast (FP) and slow pathway (SP) on AV and VA conduction in the normal dog heart using a novel epicardial ablation technique. Methods and Results : For FP ablation, radiofrequency current (RFC) was applied to a catheter tip that was held epicardially against the base of the right atrial wall. SP ablation was performed epicardially at the crux of the heart. Twenty‐three dogs were assigned to two ablation protocols: FP/SP ablation group (n = 17) and SP/FP ablation group (n = 6). In 12 of 17 dogs, FP ablation prolonged the PR interval (97 ± 10 to 149 ± 22 msec. P < 0.005) with no significant change in anterograde Wenckebach cycle length (WBCL), Subsequent SP ablation performed in 8 dogs further prolonged tbe PR interval and the anterograde WBCL (117 ± 22 to 193 ± 27, P < O.(M)5). Complete AV block was seen in I of 8 dogs, whereas complete or high‐grade VA block was seen in 6 of 8 dogs. In the SP/FP ablation group, SP ablation significantly increased WBCL with no PR changes. Combined SP/FP ablation in A dogs prolonged the PR interval significantly, but no instance of complete AV block was seen. VA block was found in 50% of these cases. Histologic studies revealed that RFC ablation affected the anterior and posterior atrium adjacent to the undamaged AV node and His bundle. Conclusion : Using an epicardial approach, combined ablation of tbe FP and SP AV nodal inputs can be achieved with an unexpectedly low incidence of complete A V block, although retrograde VA conduction was significantly compromised.