TY - JOUR
T1 - Electrophysiology of the atrio-AV nodal inputs and exits in the normal dog heart
T2 - Radiofrequency ablation using an epicardial approach
AU - Hirao, Kenzo
AU - Scherlag, Benjamin J.
AU - Poty, Hervé
AU - Otomo, Kenichiro
AU - Tondo, Claudio
AU - Antz, Matthias
AU - Patterson, Eugene
AU - Jackman, Warren M.
AU - Lazzara, Ralph
PY - 1997
Y1 - 1997
N2 - 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 the PR interval and the anterograde WBCL (117 ± 22 to 193 ± 27, P <0.005). Complete AV block was seen in 1 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 6 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 the FP and SP AV nodal inputs can be achieved with an unexpectedly low incidence of complete AV block, although retrograde VA conduction was significantly compromised.
AB - 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 the PR interval and the anterograde WBCL (117 ± 22 to 193 ± 27, P <0.005). Complete AV block was seen in 1 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 6 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 the FP and SP AV nodal inputs can be achieved with an unexpectedly low incidence of complete AV block, although retrograde VA conduction was significantly compromised.
KW - Atrioventricular conduction
KW - Atrioventricular node
KW - Dog heart
KW - Radiofrequency ablation
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M3 - Article
C2 - 9261717
AN - SCOPUS:0030752375
VL - 8
SP - 904
EP - 915
JO - Journal of Cardiovascular Electrophysiology
JF - Journal of Cardiovascular Electrophysiology
SN - 1045-3873
IS - 8
ER -