What are the components of a pacemaker?

 

State-of-the-art pacemakers are like miniaturized computers capable of monitoring the heart's spontaneous activity. When necessary, pacemakers deliver an electric pulse, which replaces a deficient spontaneous heart rhythm. The procedure involves the implantation of a pulse generator and a lead system.


Pulse Generator

The pulse generator is a sealed titanium metal container that contains:

The pulse generator's computer memory stores:

  • a battery, to power the system,

  • a microprocessor (small computer)

  • electronic circuits which monitor and analyze each heart beat and, when necessary, trigger the delivery of imperceptible low-intensity impulses, to regulate the heart rhythm.

  • programmed treatment settings,

  • outcome of each treatment,

  • electrocardiographic recordings,

  • the status of the pulse generator's battery (how much energy remains at each follow-up visit).


Pulse generator

 

From this record of the device's and heart's activity, one can monitor their behavior since last interrogation, and decide from this information whether the treatment needs adjustments. Since it is possible to communicate with the pacemaker by means of a programmer, the pulse generator's settings can be reprogrammed painlessly and non-invasively.

 


Lead system

Leads deliver the electric impulses to and from the heart. They are made of fine flexible insulated wires that link the pulse generator to the heart.

A pacemaker may function in one of the following ways:

  • single chamber pacing: 1 lead to pace the right atrium or ventricle.

  • dual chamber pacing: 1 lead to pace the atrium and 1 to pace the ventricle.

  • biventricular pacing: 1 lead to pace the atrium and 2 leads, each pacing a different ventricle.

  • rate responsive stimulation: pacing with 1 or 2 leads in the right atrium and/or right ventricle and a pulse generator capable of sensing activity level and adapting the pacingrate to demands related to rest versus exercise.

 

Your doctor will chose the pacemaker system best suited for your needs. The systems undergo strict manufacturing procedures and have to successfully pass reliability tests. The length of time before a replacement is needed depends on the pulse generator settings and the individual utilization of the system.

 

Warning: This information should not be used as a substitute to consultation from a physician.
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