Indications for permanent pacing in dogs and cats

Abstract

Pacemaker implantation is considered as a standard procedure for treatment of symptomatic bradycardia in both dogs and cats. Advanced second-degree and third-degree atrioventricular blocks, sick sinus syndrome, persistent atrial standstill, and vasovagal syncope are the most common rhythm disturbances that require pacing to either alleviate clinical signs or prolong survival. Most pacemakers are implanted transvenously, using endocardial leads, but rarely epicardial leads may be necessary. To decide whether a patient is a candidate for pacing, as well as which pacing modality should be used, the clinician must have a clear understanding of the etiology, the pathophysiology, and the natural history of the most common bradyarrhythmias, as well as what result can be achieved by pacing patients with different rhythm disturbances. The goal of this review was, therefore, to describe the indications for pacing by evaluating the available evidence in both human and veterinary medicine. We described the etiology of bradyarrhythmias, clinical signs and electrocardiographic abnormalities, and the choice of pacing modality, taking into account how different choices may have different physiological consequences to selected patients. It is expected that this review will assist veterinarians in recognizing arrhythmias that may require permanent pacing and the risk-benefit of each pacing modality and its impact on outcome. ª

Reversible third-degree atrioventricular block in a Poodle-Toy with degenerative mitral valve disease and pyometra

“…3AVB is classified as congenital or acquired, and can be transient, intermittent or permanent. It results from an interruption of the electrical impulse between atria and ventricles, due to an anatomical or functional impairment in the AV conduction system (Santilli et al, 2019). This case arrhythmia was classified as transient since it was spontaneously reverted to sinus rhythm after the OSH.…”

“…Several primary or secondary disorders of the AV conduction system are capable of inducing 3AVB, but usually, the cause is unknown (Willis, 2018). However, many underlying causes for 3AVB in canines have been cited including degeneration and fibrosis of the AV conduction system (Kaneshige et al, 2007), isolated congenital AV block, inherited heart defects, adrenal insufficiency (Patterson et al, 1961), myocarditis, cardiomyopathy, infections, myocardial infarction, hyper-hypokalemia, drugs intoxication (digoxin and calcium channel blockers), cardiac neoplasia, immune-mediated and inflammatory diseases (myasthenia gravis, lupus erythematosus), trauma, inflammation and systemic disorders (Willis, 2018;Santilli et al, 2019) and pancreatitis (Oron et al, 2015).…”

Single-Chamber Cardiac Pacemaker Implantation in a Donkey with Complete AV Block: A Long-Term Follow-Up

“…Cardiac pacing is an effective therapy for various arrhythmias in humans and a therapeutic implantation of a cardiac pacemaker has also been described in a horse [ 1 , 2 , 3 , 4 ] and a donkey [ 5 , 6 ]. Indications for pacemaker implantation are symptomatic bradycardic arrhythmias such as third-degree AV block, high-grade second-degree AV block, sick sinus syndrome or persistent atrial standstill [ 1 , 3 , 5 , 6 , 7 , 8 , 9 , 10 ]. Transvenous pacemaker implantation is a relatively safe and simple procedure.…”

Successful transcutaneous pacing following ventricular standstill during anaesthetic induction in a dog with third‐degree atrioventricular block

“…Permanent pacemaker implantation is indicated in dogs with symptomatic bradycardias including high-grade second degree and third-degree atrioventricular (AV) block, sick sinus syndrome and sinus arrest. 1 Cardiac arrest during implantation of permanent pacemakers is an occasionally reported complication of the surgical procedure itself, occurring consequently to ventricular fibrillation. 2 3 Often, exacerbation of bradycardias may be detected following induction of general anaesthesia in these dogs, with one retrospective study identifying a requirement for temporary transcutaneous pacing (TCP) in 27 out of 77 cases.…”