Electroanatomic substrate of idiopathic left ventricular tachycardia: unidirectional block and macroreentry within the purkinje network.
BACKGROUND
An abnormal potential (retroPP) from the left posterior Purkinje network has been demonstrated during sinus rhythm (SR) in some patients with idiopathic left ventricular tachycardia (ILVT). We hypothesized that this potential can specifically be identified and be a critical substrate for ILVT.


RESULTS
In 9 patients with ILVT and 6 control patients who underwent mapping of the left ventricle during SR using 3-dimensional electroanatomic mapping, an area with retroPP was found within the posterior Purkinje fiber network only in patients with ILVT. The earliest and latest retroPP was 185.4+/-57.4 and 465.2+/-37.3 ms after Purkinje potential; in the other patient with ILVT, an entire left ventricle mapping demonstrated a slow conduction area and passive retrograde activation along the posterior fascicle during ILVT. ILVT was noninducible in 3 patients after SR mapping. Diastolic potentials critical for ILVT during ILVT coincided with the earliest retroPP during SR in 7 patients. Mechanical termination of ILVT occurred in 5 patients. A single radiofrequency pulse was applied at the site with mechanical translation in 5 patients and the site with diastolic potential in 2 patients, and 3 radiofrequency pulses were delivered to the site with the earliest retroPP in the other 3 patients without inducible ILVT after SR mapping. No ILVT was inducible during control stimulation, and none recurred during follow-up of 9.1+/-5.1 months.


CONCLUSIONS
In patients with ILVT, abnormal retroPP within the posterior Purkinje fiber network is a common finding. The earliest retroPP critical for ILVT substrate can be used for guiding successful ablation.
Ouyang
Feifan
F
Zweite Medizinische Abteilung, Allgemeines Krankenhaus St Georg, Hamburg, Germany. Ouyangfeifan@aol.com
Cappato
Riccardo
R
Ernst
Sabine
S
Goya
Masahiko
M
Volkmer
Marius
M
Hebe
Joachim
J
Antz
Matthias
M
Vogtmann
Thomas
T
Schaumann
Anselm
A
Fotuhi
Parwis
P
Hoffmann-Riem
Martin
M
Kuck
Karl-Heinz
KH
D000293:Adolescent; D000328:Adult; D018780:Body Surface Potential Mapping / Q000379:methods*; D017115:Catheter Ablation; D002648:Child; D004558:Electric Stimulation; D004699:Endocardium; D005500:Follow-Up Studies; D006327:Heart Block / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy; D006329:Heart Conduction System; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008297:Male; D011690:Purkinje Fibers / Q000503:physiopathology*; D012849:Sinoatrial Node / Q000503:physiopathology; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000209:etiology* / Q000503:physiopathology / Q000628:therapy; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy