VENTRICULAR FUSION DURING RESETTING AND ENTRAINMENT OF ORTHODROMIC SUPRAVENTRICULAR TACHYCARDIA INVOLVING SEPTAL ACCESSORY PATHWAYS - IMPLICATIONS FOR THE DIFFERENTIAL-DIAGNOSIS WITH ATRIOVENTRICULAR NODAL REENTRY

Citation
Jm. Ormaetxe et al., VENTRICULAR FUSION DURING RESETTING AND ENTRAINMENT OF ORTHODROMIC SUPRAVENTRICULAR TACHYCARDIA INVOLVING SEPTAL ACCESSORY PATHWAYS - IMPLICATIONS FOR THE DIFFERENTIAL-DIAGNOSIS WITH ATRIOVENTRICULAR NODAL REENTRY, Circulation, 88(6), 1993, pp. 2623-2631
Citations number
26
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cardiac & Cardiovascular System",Hematology
Journal title
Circulation → ACNP
ISSN journal
0009-7322
Volume
88
Issue
6
Year of publication
1993
Pages
2623 - 2631
Database
ISI
SICI code
0009-7322(1993)88:6<2623:VFDRAE>2.0.ZU;2-S
Abstract
Background. Ventricular fusion during transient entrainment of orthodr omic atrioventricular reciprocating tachycardias (OAVRT) was originall y found to be absent and recently observed only with left ventricular stimulation. However, previous studies were restricted to cases with a left free wall accessory pathway. The hypothesis of the present study was that fusion is likely during resetting and entrainment of OAVRT w ith right ventricular stimulation if the accessory pathway is septally located, since its insertion is relatively close to the stimulation s ite. This phenomenon can help in the differential diagnosis with atrio ventricular nodal reentry (AVNR). Methods and Results. We performed pr ogrammed right ventricular stimulation during regular inducible suprav entricular tachycardia with concentric atrial activation in 44 patient s-20 with OAVRT and 24 with AVNR. Fusion in the ECG morphology of extr astimuli producing resetting was observed in 19 of 19 OAVRT but in 0 o f 11 AVNR reset (P<.001). Transient entrainment was demonstrated in al l 31 cases undergoing rapid ventricular pacing (14 OAVRT and 17 AVNR). Entrainment with fusion occurred in 13 of 14 OAVRT and in 0 of 17 AVN R (P<.001). Fusion was critically dependent on the coupling intervals or pacing rates, sometimes having a narrow window for its observation. Conclusions. The relative proximity (conduction time) among pacing si te, site of entrance to a reentrant circuit, and site of exit from the circuit to the paced chamber are critical for the occurrence of fusio n during resetting and/or entrainment. The presence or absence of fusi on during these phenomena can help in the differential diagnosis of ce rtain supraventricular tachycardias.