Orthodromic Reciprocating Tachycardia Relying on Aberrant Conduction:
Need for a Lager Circuit
Abstract
Background Aberrant conduction during orthodromic
reciprocating tachycardia (ORT) can prolong the ventriculo-atrial
conduction time, which is found essential for the reentry in certain
situations. Materials and Methods We searched for ORT
cases relying on aberrancy from 220 cases in our center.
Results 3 patients showed the phenomenon of
aberrancy-dependent ORT. All accessory pathways were located at
anterolateral regions of atrioventricular annulus. None of them had
baseline bundle branch block. Creating functional bundle branch block
was necessary to induce the tachycardias. In 2 cases, termination
directly associated with resolution of aberration was observed. While in
the other case, reentry required both interventricular block and slow
pathway conduction. Conclusions We conclude that extra
transseptal time caused by aberrancy can be an integral part of ORT,
which can explain the infrequent or late onset and unsustainable
episodes of ORT in certain patients and is useful in understanding the
circuit and localizing the pathway.