Clinical implications of "pure" Hisian pacing in addition to para-Hisian pacing for the diagnosis of supraventricular tachycardia.
BACKGROUND
Para-Hisian pacing is an effective method of differentiating between pathways for retrograde conduction over the accessory pathway (AP) and over the atrioventricular node (AVN). When performing para-Hisian pacing, the pacing spike sometimes captures only the His bundle, which we named "pure" Hisian pacing (Hc).


OBJECTIVE
We evaluated the significance of pure Hisian pacing for predicting the pathways of ventriculoatrial conduction.


METHODS
In 62 patients with supraventricular tachycardia, both para-Hisian and pure Hisian pacing were carried out during the sinus rhythm, resulting in three different types of electrocardiographic complexes with wide (local ventricular myocardial capture), slightly narrow (both local myocardial and His bundle capture), and very narrow QRS widths (Hc). A change of atrial activation sequence as demonstrated by these pacing modes indicated the presence of multiple retrograde pathways. The diagnosis of retrograde pathways by para-Hisian pacing with or without Hc was evaluated.


RESULTS
In 22 patients with AVN reentrant tachycardia, para-Hisian pacing alone was able to correctly predict ventriculo-atrial conduction exclusively through the AVN without requiring findings from Hc. In 40 AP patients, para-Hisian pacing showed a pattern of retrograde conduction through the AVN in six, through both the AVN and AP in 10, and through an AP in 24 patients. Four of these 24 patients were diagnosed as having multiple pathways (AP+AVN or dual APs) by the addition of Hc.


CONCLUSIONS
Pure Hisian pacing can help disclose another pathway for retrograde conduction in AP patients, which is unpredicted by ordinary para-Hisian pacing.
Takatsuki
Seiji
S
Lariboisiere University Hospital, Paris, France. tktksj37@yahoo.co.jp <tktksj37@yahoo.co.jp>
Mitamura
Hideo
H
Tanimoto
Kojiro
K
Fukuda
Yukiko
Y
Ieda
Masaki
M
Miyoshi
Shunichiro
S
Soejima
Kyoko
K
Extramiana
Fabrice
F
Leenhardt
Antoine
A
Ogawa
Satoshi
S
D001283:Atrioventricular Node / Q000503:physiopathology; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D003937:Diagnosis, Differential; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012107:Research Design; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000175:diagnosis; D013614:Tachycardia, Paroxysmal / Q000175:diagnosis; D013617:Tachycardia, Supraventricular / Q000175:diagnosis* / Q000503:physiopathology; D013997:Time Factors