Question: What is a cardiac resynchronization device, and is it the same as a pacemaker?
Answer:Well, in a way it's similar to a pacemaker. A pacemaker was developed for patients with slow heart rhythms and so one paces the heart at a more-normal heart rate.
So if a person has an exceedingly slow heart rate of say 30 or 20 beats per minute, that does not function very well and so pacemakers were developed to improve the heart rate and these can be set at 70 or 80 beats per minute, which is in the more normal range. Now resynchronization therapy is trying to address a totally different situation. The heart, when it's electrically stimulated, the normal heart contracts in a very uniform way.
When there has been scar tissue or alteration in the electrical conduction within the heart, hearts can contract in different regions at different times and they can actually end up opposing one another rather than creating a uniform contraction pattern.
It's now been recognized that by stimulating certain areas in the left ventricle, one can produce more uniform contraction when there is a contraction pattern abnormality. And the stimulation of this is done by a pacemaker technique, but it's a pacemaker that's directed towards improving the mechanical contraction pattern of the heart rather than trying to increase the heart rate.
So one can say resynchronization is to treat patients who have impaired contraction -- heart failure as a general rule, is the reason it's being utilized, whereas the traditional pacemaker is being used for treatment of very slow heart rhythms and has nothing to do with the contraction pattern.