Dual Chamber Pacemaker Implantation in Dogs with Atrioventricular Block

Abstract

Background: Pacemaker implantation is the treatment of choice for symptomatic bradyarrhythmias. In dogs, a single chamber system is commonly used. In human patients with high-grade 2nd-or 3rd-degree atrioventricular (AV) block, physiologic pacing is recommended, because it improves cardiac output, blood pressure, exercise tolerance, and quality of life. In dogs, this type of pacing is seldom used.Hypothesis: The implantation of a dual chamber pacemaker in dogs with AV block is a feasible procedure for restoring AV synchrony.Animals: Thirty-three privately owned dogs with high-grade 2nd-or 3rd-degree AV block were included. Methods: Patient data of all dogs with AV block presented for pacemaker implantation between December 1997 and November 2004 were reviewed.Results: Dual chamber pacemaker implantation with AV synchronous stimulation was successfully performed in 33/33 dogs (100%). In 9/33 (27%) major and in 12/33 (36%) minor complications were observed. Mean survival time for the patients discharged from hospital (n 5 32) was 33.6 AE 20.4 months (range, 3.9-83.5 months).Conclusion and Clinical Importance: Dual chamber pacing is a feasible procedure in dogs with 2nd-or 3rd-degree AV block and is not associated with a higher complication rate compared with single chamber pacemaker systems. A major advantage over ventricular demand pacemaker systems is the restoration of AV synchrony for a substantial period of time.

Indications for permanent pacing in dogs and cats

“…9A and B). As per the guidelines for human patients [67], the primary indication for single lead physiologic pacing is third-degree AVB with normal SA node function, because VDD PMs are unable to pace the atria during periods of sinus arrest and they are unable to maintain AV synchrony in patients with sinus node disease [3,10,110]. The prevalence of chronotropic incompetence in dogs with third-degree AVB is unknown.…”

“…Lead II, paper speed 50 mm/s, calibration 10 mm/1 mV. associated with AV valvular or primary myocardial disease is reported in 3.6%e11.5% of patients [2,7,9,10,12]. Furthermore, patients affected by third-degree AVB associated with chronic degenerative mitral valve disease or dilated cardiomyopathy may be more sensitive to bisynchronous apical right ventricular pacing [158].…”

Permanent dual chamber epicardial pacemaker implantation in two dogs with complete atrioventricular block

“…17 The use of transvenous dual chamber pacemaker systems has been reported in veterinary medicine in various publications. 6,18,19 The use of a dual chamber single lead VDD system has been shown to significantly improve hemodynamics and neurohormonal parameters with a complication rate comparable to single chamber ventricular pacing in dogs. 18,19 There are currently no available long-term survival data on dogs with dual chamber systems.…”

Use of transcutaneous external pacing during transvenous pacemaker implantation in dogs

“…During this invasive technique, an endocardial pacing lead is placed into the right ventricle via the systemic venous system and attached to an external pulse generator. Sisson and others (1991), Oyama and others (2001), Wess and others (2006), Johnson and others (2007) and Hildebrandt and others (2009) used TTP in 10 per cent (four of 40), 46 per cent (69 of 154), 82 per cent (78 of 105), 50 per cent (52 of 104) and 24 per cent (eight of 33) of dogs that underwent PMI, respectively. There are also some reports on the use of TTP during PMI in single cases (Lombard and Buchanan 1976, Flanders and others 1999, Bulmer and others 2006, Saunders and others 2007).…”