Southern Counties Veterinary Specialists 01425 485615



Single and Dual Chamber Pacemakers at SCVS

  • SCVS offers the option of single and dual chamber pacemaker to achieve best results for all patients
  • Predominant use of active electrodes to minimise the risk of lead dislogement
  • Pacemaker clinics with electrophysiologist to ensure best possible pacemaker programming
  • Please contact SCVS on 01425 485 615 and ask for a member of the cardiology team if you have a patient which might be suitable

General Information about Pacemakers

How does a pacemaker work?

A pacemaker system comprises an intracardiac lead connected to a pulse generator (battery and electronics). The system monitors the heart rate and rhythm. If the heart rate becomes too slow or if 
there are long pauses between heart beats, the pacemaker system “senses” this and delivers electrical impulses to the heart stimulating heart beats. Cardiac output (and therefore cerebral blood pressure), is maintained, thereby preventing fainting episodes and allowing the patient to enjoy a normal quality of life.

How is a pacemaker placed?

Only two small skin incision at the neck are required. A pacemaker lead is then inserted via the jugular vein to the heart. This is connected to the pulse generator, which is positioned in the neck.

Are there any restrictions to the patient following pacemaker implantation?

Following pacemaker implantation, most patients live a normal quality of life. Restricted exercise is only required during the first 
few weeks after surgery, to minimize risk of lead dislodgement. 
At SCVS we use active leads, which allows for more secure lead placement, thereby reducing time needs for exercise restriction and the risk of lead dislodgement.

What 'maintenance' does a pacemaker require?

At SCVS we re-examine our pacemaker patients initially at 1, 3 and 6 months post-surgery. If no problems are detected, then pacemaker patients need only be reassessed once a year.

Single versus Dual Chamber Pacemakers

Single chamber pacemaker systems have only one lead. The pacemaker lead is typically positioned in the right ventricle of the heart. The intracardiac lead “senses” heart beats and maintains the heart rate within programmed ranges, thereby preventing fainting episodes. Single chamber pacemakers have activity sensors and can the trim heart rate according to activity levels and actually work well in most situations. However, this type of pacemaker system cannot sense the sinus node or atria, therefore cannot “use” the natural rhythm of the heart to pace the ventricles, nor can it achieve normal synchronous atrial and ventricular contractions. 



 Dual chamber pacemaker systems use two leads; one is positioned in the right ventricle and the other in the right atrium. Whilst placement and programming of a dual chamber pacemaker is more complex, it offers many advantages. In contrast to the single chamber system, the dual chamber pacemaker system can “sense” both atrial and ventricular activity. It can therefore use the dog's normal physiological heart rhythm (as determined by the sinus node) to set the ventricular rate and rhythm, but can also take over pacing when this fails. It can also ensure synchronous atrial and  ventricular pacing, even when the heart is “pacemaker dependent”. In human medicine, Dual chamber pacemaker system is used almost exclusively, as they preserve physiological control of the heart rate and rhythm and are therefore superior to single chamber systems in most circumstances. Single chamber systems are more commonly used in veterinary patients, partly because complexity of fitting and programming dual chamber systems. We have worked with colleagues from human medicine in developing dual-chamber pacing in dogs and are therefore very pleased to offer this more complex pacemaker version at SCVS when it is indicated. 

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