Electrophysiologic Characteristics and Topographic Distribution of Focal Atrial Tachycardias in Dogs

Abstract

Background: Focal atrial tachycardia (FAT) is a common supraventricular tachycardia in dogs.Objective: To evaluate electrophysiologic characteristics and topographic distribution of FAT. Animals: Sixteen dogs with symptomatic FAT. Methods: Retrospective case series. Electrophysiological studies were performed to test the inducibility of documented and no documented arrhythmias. Once induced for each dog, FAT was analyzed for electrogenic mechanism, endocardial electrogram, and location.Results: Nineteen FATs could be studied in 16 dogs, 12 were automatic, 4 nonautomatic, and 3 incessant. Two dogs had 41 focus. Mean atrial cycle length (CL) was 238.2 AE 69.2 (SD) milliseconds, mean ventricular CL of 292.7 AE 72.5 (SD) milliseconds, with atrioventricular block in 6 cases. Mean presystolic atrial activity recorded at the ectopic focus was -39.9 AE 17.7 (SD) milliseconds. Atrial potentials were fragmented in 11 dogs and were low amplitude in 6 dogs. Sixty-three percent of ectopic foci were distributed within the right atrium (5 crista terminalis, 3 triangle of Koch, 2 tricuspid valve annulus, 1 interatrial septum, and 1 right auricle) and 37% in the pulmonary veins (PVs) (4 right superior PV, 2 left superior PV, and 1 right inferior PV). Persistent atrial fibrillation (AF) and paroxysmal AF were triggered by FATs in 7 dogs (2 with multiple ectopic foci and 4 with at least one PV focus).Conclusion and Clinical Relevance: According to our findings, dogs have a predominance of right-sided FAT. The majority of FATs are automatic and can trigger AF, particularly in the case of PV location.

Experimental Model of Focal Atrial Tachycardia: Clinical Correlates

“…Although the incidence of focal atrial tachycardia in humans is reported to occur in 10% of patients with supraventricular tachycardias, focal atrial tachycardia is more common in dogs . Of interest, the distribution of sites at which the majority of focal ATs arise is the same in both dogs and man . For example, both species show that the focal ATs arise commonly at the crista terminalis.…”

P' wave axis analysis for the identification of sustained focal atrial tachycardia from low atrial origin - case report

“…The diagnosis of the electrogenic mechanism of a supraventricular tachycardia can be only made by endocardial mapping (5,9,11). The use of surface ECG and Holter monitoring provide only a suspicious of diagnosis.…”

Phenotypic description of cardiac findings in a population of Dogue de Bordeaux with an emphasis on atrial fibrillation

“…In human beings, paroxysmal SVT is closely associated with paroxysmal AF and it has been suggested that SVT might predispose to AF development because of atrial stretch, reduced atrial refractoriness and vagal activation during tachycardia (Chang et al, 2008). Focal atrial tachycardia (FAT) was reported in two DdB in a series of 16 dogs diagnosed with FAT by electrophysiological study (Santilli et al, 2010). Seven of these dogs had a surface ECG diagnosis of AF.…”