Iijima T, Kaneko Y, Nakajima T, Irie T, Ota M, Saito A, Kurabayashi M. Measurement of the ventriculoatrial interval from the coronary sinus during para-Hisian pacing may fail to distinguish ventriculoatrial nodal conduction from conduction over a septal accessory pathway.
J Arrhythm 2015;
31:33-7. [PMID:
26336521 DOI:
10.1016/j.joa.2014.05.005]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 05/13/2014] [Accepted: 06/02/2014] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND
Para-Hisian pacing (PHP) helps differentiate retrograde conduction over an accessory pathway (AP) from retrograde conduction over the atrioventricular (AV) node. This study examined a potential limitation of this technique, focusing on the measurement of the ventriculoatrial (V-A) interval from the coronary sinus (CS) during PHP.
METHODS
Our subjects were 9 patients undergoing electrophysiological studies before successful catheter ablation of a posteroseptal AP. During PHP, retrograde conduction occurred over an AP when the pacing stimulus to atrium (S-A) interval recorded near the AP remained unchanged whether the His bundle (HB) was captured or not (pattern 1), or when a loss of HB capture was associated with an increase in the S-A interval and no change in the V-A interval near the AP (pattern 2).
RESULTS
Patterns 1 and 2 were observed in 5 (56%) and 2 (22%) patients, respectively. However, in the remaining 2 patients (22%), loss of HB capture during PHP was associated with an increase in the S-A interval (as in pattern 2), whereas the V-A interval near the AP could not be measured because no ventricular electrogram was visible on the CS recording (pattern 3); therefore, the presence of AP could not be confirmed by PHP. In patterns 2 and 3, the atrial activation sequence remained unchanged whether the HB was captured or not.
CONCLUSIONS
PHP may not be able to discriminate between a retrograde septal AP and AV nodal conduction in patients whose proximal CS recording shows no visible ventricular electrogram.
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