Intracardiac electrophysiological conduction parameters in adult dogs

Abstract

Background: Invasive electrophysiology study (EPS) is one of the most important adjunct tests for the evaluation of arrhythmias in human medicine. However, EPS is neither well known nor widely used in veterinary medicine. Objective: To define the values for intracardiac conduction parameters determined during invasive EPS in dogs. Animals and methods: The study included 16 admitted dogs of various breeds, sex and ages and 6 control Beagles. In the Beagles, EPS was performed twice at 6-month intervals in order to verify the reproducibility of the results. Results: No significant differences were found between the results of the baseline and repeated EPS performed in the Beagles. We found retrograde conduction in 13 (59%) out of 22 dogs and including 4 (31%) animals with concomitant 'jumps' in the atrioventricular node conduction curve, pointing to the presence of dual conduction in this node. The mean values of the AV and retrograde VA Wenckebach points equaled to 220 and 360 ms, respectively, suggesting that the capability of the descending route is higher than that of the ascending route. Conclusion:The values determined in this study may be helpful in early detection of abnormalities in the electrical conduction system of the heart.

Analysis of haematological and biochemical blood parameters after electrical cardioversion of atrial fibrillation in dogs

“…Its self-perpetuating nature leads to electrical and eventually structural remodelling expressed as a shortened atrial refractory period, atrial refractoriness dispersion, calcium overload, disseminated tissue fibrosis, and hypertrophy and dilatation of the atria (15). A rapid ventricular response rate, in many cases exceeding 260 bpm, results from very effective conduction within the atrioventricular node in dogs (3). It is often the cause of sudden development of tachycardia-induced cardiomyopathy (TICM) (15,18).…”