The Annals of Thoracic Surgery, Vol 57, 1273-1280, Copyright © 1994 by The Society of Thoracic Surgeons
Anatomic definition of a vulnerable extranodal site in AV node reentry
WL Holman, PG Anderson, RD Spruell and AD Pacifico
Department of Surgery, University of Alabama at Birmingham 35294.
The success of methods that ablate atrioventricular (AV) node reentry
demonstrates that extranodal tissue is part of the reentry circuit. The
hypothesis of this study is that atrial tissue approaching the posterior AV
node is part of the AV node reentry circuit and is especially suitable for
complete division with sparing of AV conduction. This study measured AV
node function after either an anterior or posterior perinodal incision. The
only significant change noted in antegrade function was a lengthening of
the Wenckebach point after the posterior incision. Retrograde AV conduction
and ventricular echoes were abolished by the posterior incision, whereas
the anterior incision had no discernible effect on retrograde AV node
function. Anatomic analysis of the two incisions showed that the posterior
incision completely interrupted the posterior atrial input to the AV node,
whereas the anterior incision spared the medial input to the AV node. The
atrial tissue posterior to the AV node is anatomically suited for complete
interruption. Ablation of atrial tissue posterior to the AV node is
proposed for abolishing AV node reentrant tachycardia.