title: Mapping guided laser catheter ablation of the atrioventricular conduction in dogs.
abstract: Safety and efficacy of mapping guided laser catheter ablation of the AV junction was tested in a canine model. A total of 43 laser pulses (continuous wave, Nd:YAG, 1,064 nm, 30 W, irradiated spot diameter 2.0-2.5 mm) were delivered in 15 dogs (2-5 per dog) via a novel laser catheter system. Pulses were selectively aimed at: (1) the AV node; (2) the His bundle; and (3) the bundle branches. Laser pulses of 9.7 +/- 1.1 seconds (n = 31) produced reversible conduction disturbances in the targeted segment of the AV conduction system, while pulses of 28.6 +/- 7.9 seconds (n = 9) resulted in chronic block. The dogs survived the procedure without complications. Follow-up was 6.5-10.5 months. Histopathologically, lesions showed clear-cut oval-shaped areas of fibrosis of 0.5-18.0 mm in diameter and 0.5-3.5 mm (transmural) in depth, depending on the irradiation time. Pervenous mapping guided laser catheter irradiation of the AV junction can produce AV block consistently and selectively in the targeted segment of the right ventricular conduction system in dogs. The method is safe and can be performed in a controllable manner by using the catheter system presented.
authors.affiliation: 1st Medical Department, Harlaching Hospital, Germany.
authors.forename: H P
authors.initials: HP
authors.lastname: Weber
authors.forename: A
authors.initials: A
authors.lastname: Heinze
authors.forename: S
authors.initials: S
authors.lastname: Enders
authors.forename: L
authors.initials: L
authors.lastname: Ruprecht
authors.forename: E
authors.initials: E
authors.lastname: Unsöld
mesh_terms: D000818:Animals; D001283:Atrioventricular Node / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D002036:Bundle of His / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation / Q000295:instrumentation*; D004285:Dogs; D004562:Electrocardiography; D005260:Female; D005583:Fourier Analysis; D006327:Heart Block / Q000473:pathology / Q000503:physiopathology; D053685:Laser Therapy / Q000295:instrumentation*; D008297:Male; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation; D013617:Tachycardia, Supraventricular / Q000473:pathology / Q000503:physiopathology / Q000601:surgery