Pacemaker

[Guenter]

I am completely pacemaker dependent now.  I have received conflicting information regarding what happens should the lead or generator fails (I have a VVIR pacer).  I have been told that there would be an escape rhythm of some sort to sustain life until the pacer could be changed.  Another source told me that generally speaking if one has been totally pacemaker dependent for a year, it would be unlikely that there would be an escape or intrinsic rhythm.  Could you tell me what is actually likely to happen?

[Cleveland Clinic]

guenter,

Alot depends on the rhythm you have that the pacemaker was placed for. Generally each of the cells in the heart have the ability to generate their own signal to beat.  So each of the cells can be a pacemaker.  The difference is the rate at which each cell 'beats'.  The conduction system of the heart generally beats faster, and can be stimulated and regulated through the specialized areas of conduction known as the nodes..SA and AV. Also, the cells in the heart have the ability to stimulate each other, a term known as syncitium.
Genrally, the hearts intrinsic wiring takes care of stimulating all of the cells in the heart to beat together. When the hearts conducting system isnt working, the pacemaker takes over the stimulation of the heart.  If the pacemaker fails or the wiring isn't working, then the isolated cells of the heart can take over and generate a slower heart rate based on their own pacemaker properties.  This 'escape rhythm' generally is slower and will often lead to marked symptoms.  

Pacemakers today are very durable. Lead failures are not as common and generator failures are exceedingly rare if you go through regular pacemaker checks.

[Guenter]

Thanks for your very excellent answer.  I have a pacemaker because I had an AV node ablation for uncontrolled atrial fibrillation.  Would I be more likely to have an escape rhythm?

[Cleveland Clinic]

The ventricles ability to generate their own beat is independant of the other portions of the heart. Generally, they will still generate an escape rhythm, albeit a slow one.

good luck

[Irene]

I very rarely view this site nowadays as I feel that too many of the comments posted by the 'regulars responders' are taken by some readers as legitimate medical opinion, despite the warning notice to the contrary, and this makes the whole site a little dangerous.  However I just wanted to say that I am, like you, pacemaker dependent for the same reason, and I do have a clear escape rhythm. You should find that when the technician does your annual pacemaker check, he or she will test this by 'switching off' the pacemaker for a few seconds.  Good luck with your pacemaker.