RADIOFREQUENCY CATHETER ABLATION OF IDIOPATHIC LEFT-VENTRICULAR TACHYCARDIA GUIDED BY A PURKINJE POTENTIAL

Citation
H. Nakagawa et al., RADIOFREQUENCY CATHETER ABLATION OF IDIOPATHIC LEFT-VENTRICULAR TACHYCARDIA GUIDED BY A PURKINJE POTENTIAL, Circulation, 88(6), 1993, pp. 2607-2617
Citations number
37
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cardiac & Cardiovascular System",Hematology
Journal title
ISSN journal
0009-7322
Volume
88
Issue
6
Year of publication
1993
Pages
2607 - 2617
Database
ISI
SICI code
0009-7322(1993)88:6<2607:RCAOIL>2.0.ZU;2-Q
Abstract
Background. Verapamil-sensitive, idiopathic left ventricular tachycard ia (ILVT) with right bundle branch block configuration and left-axis d eviation has been suggested to originate from the left posterior fasci cle. The purpose of this study was to determine how frequently potenti als generated by the Purkinje fiber network (P potential) can be recor ded preceding ventricular activation, and the role of the P potential in guiding radiofrequency catheter ablation. Methods and Results. Eigh t patients (mean age, 26+/-10 years) with ILVT (cycle length, 346+/-59 milliseconds) were studied. Right and left ventricular endocardial ma pping during tachycardia identified earliest ventricular activation at the posteroapical left ventricular septum. In all patients, earliest ventricular activation during tachycardia was preceded by a distinct p otential. This potential also preceded ventricular activation during s inus rhythm, consistent with activation of a segment of the left poste rior fascicle (P potential). The earliest recorded P potential precede d the QRS during tachycardia by 15 to 42 milliseconds (mean, 27+/-9 mi lliseconds). The application of radiofrequency current at 1 to 4 sites (median, 1) eliminated ILVT in all eight patients. In the seven patie nts with P potentials recorded at multiple sites within the posteroapi cal septum, ablation was successful at the site of the earliest P pote ntial and unrelated to the timing of ventricular activation. In the re maining patient, ablation was successful at a site recording a late P potential fusing with earliest ventricular activation. During follow-u p (1 to 67 months; median, 10.5) ILVT recurred only in the latter pati ent. Pace mapping during tachycardia at the successful ablation site i n four patients produced a similar QRS with stimulus-QRS interval equa l to P-QRS interval during tachycardia. However, a similar QRS was obt ained by pacing at nearby sites that recorded a later P potential. Con clusions. These findings support the hypothesis that ILVT originates f rom the Purkinje network of the left posterior fascicle. AP potential can be recorded at the posteroapical left ventricular septum during IL VT, and ablation is successful at the site recording the earliest P po tential. Pace mapping with similar QRS is not specific due to capture of the Purkinje fiber network at a site remote from the origin of the tachycardia.