Radiofrequency catheter ablation of atypical atrial flutter in dogs.
Five dogs were presented to our institution for fatigue caused by an incessant supraventricular tachycardia. In all dogs, an ECG on admission showed a narrow QRS complex tachycardia with a median ventricular cycle length of 220 ms (range 180-360 ms), and a positive atrial depolarization identifiable in the ST segment following the previous QRS complex. There was a 1:1 atrioventricular conduction ratio in all but one dog, which presented with 2:1 atrioventricular block. Electrophysiologic studies identified the underlying arrhythmogenic mechanism as a right atrial macro-reentrant tachycardia with two distinct isthmic areas: right septal (RS) in three dogs and right atrial free wall (RAFW) in two dogs. Linear radiofrequency catheter ablation was performed during tachycardia in all dogs at the identified isthmic area, which acutely blocked the macroreentrant circuit. At 18-month follow-up, 3 dogs (1 with RAFW isthmus and 2 with RS isthmus) showed no recurrence of the arrhythmia on Holter monitoring. One dog with RS isthmus showed recurrence of the supraventricular tachycardia 15 days post-ablation, and 1 dog with RAFW isthmus presented with persistent atrial fibrillation 2 months post-ablation.
Clinica Veterinaria Malpensa, Viale Marconi, 27, 21017 Samarate Varese, Italy. Electronic address: r.santilli@ecgontheweb.com.
Roberto A
RA
Santilli
Clinica Veterinaria Malpensa, Viale Marconi, 27, 21017 Samarate Varese, Italy.
Lucia
L
Ramera
Clinica Veterinaria Malpensa, Viale Marconi, 27, 21017 Samarate Varese, Italy.
Manuela
M
Perego
Humanitas Mater Domini, Via Gerenzano, 2, 21053 Castellanza Varese, Italy.
Paolo
P
Moretti
Humanitas Mater Domini, Via Gerenzano, 2, 21053 Castellanza Varese, Italy.
Giammario
G
Spadacini
D000818:Animals; D001282:Atrial Flutter / Q000628:therapy / Q000662:veterinary*; D017115:Catheter Ablation / Q000662:veterinary*; D004283:Dog Diseases / Q000628:therapy*; D004285:Dogs; D005260:Female; D008297:Male
Arrhythmias; Electrophysiology; Supraventricular tachycardia