Electrophysiological characteristics and radiofrequency ablation of accessory pathways with slow conductive properties.
BACKGROUND
Atrioventricular accessory pathways (AP) with unusually long ventriculo-atrial (VA) conduction times are present in a significant subset of patients with the Wolff-Parkinson-White (WPW) syndrome, not including patients with the permanent form of atrioventricular junctional reciprocating tachycardia.


RESULTS
We compared the electrophysiological characteristics and outcomes after radiofrequency (RF) ablation in 34 patients with the WPW syndrome, a VA interval >80 ms, and paroxysmal tachycardia with an RP/PR ratio <1 (the slow group), vs 80 patients with WPW syndrome and a VA interval <80 ms (the fast group). AP were found in the posteroseptal region significantly more often in the slow than in the fast group. In addition, the decremental conductive properties of the AP were more common in the slow than in the fast group. Catheter ablation of AP was highly successful in both groups, although ablation required a greater number of RF applications and longer procedure times in the slow group, especially for AP with decremental conductive properties.


CONCLUSIONS
A posteroseptal AP location was more common in AP associated with long conduction times than in AP with typical conductive properties. Both types of AP were successfully ablated, although the slow group required longer procedures and more RF energy deliveries.
Manita
Mamoru
M
Department of Medicine and Biological Science, Gunma University Graduate School of Medicine, Showa-machi, Maebashi, Gunma, Japan. MamiMamo@aol.com
Kaneko
Yoshiaki
Y
Kurabayashi
Masahiko
M
Yeh
San-Jou
SJ
Wen
Ming-Shien
MS
Wang
Chun-Chieh
CC
Lin
Fun-Chung
FC
Wu
Delon
D
D000293:Adolescent; D000328:Adult; D000368:Aged; D001283:Atrioventricular Node / Q000503:physiopathology; D006328:Cardiac Catheterization; D017115:Catheter Ablation; D002648:Child; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013614:Tachycardia, Paroxysmal / Q000209:etiology; D013617:Tachycardia, Supraventricular / Q000209:etiology; D013997:Time Factors; D014927:Wolff-Parkinson-White Syndrome / Q000150:complications / Q000503:physiopathology* / Q000601:surgery*