Medical Questions » Heart Questions » Question No. 508
| Question: | My grandfather is very proud that he has a little computer in his chest that he says is a pacemaker. He claims that he is the only computerised grandfather I have! What does a heart pacemaker do? |
| Answer: | The heart has a collection of nerve cells near its top end that act as a natural pacemaker. This fires off signals about once a second to make the muscles of the heart contract and pump the blood around the body. If this natural pacemaker is damaged, or the nerve fibres leading away from it are damaged, it will not function properly, and the heart will beat irregularly, at the wrong rate or not at all.
There are many reasons for the heart' s pacemaker malfunctioning, but the most common is a heart attack.
To correct the failure of the natural pacemaker, a small electrical device is surgically implanted in the chest with tiny wires leading to the appropriate part of the heart. This device is an artificial pacemaker, and it sends electrical signals to the heart on a regular basis to make the heart contract correctly. The pacemaker contains a battery, a timing device and the electrical stimulation mechanism. The battery has to be replaced every year or two.
The latest more sophisticated pacemakers contain a computer that actually monitors the heart, and only sends off an artificial signal when the hearts natural rhythm is disrupted. Variable-rate pacemakers, which increase the heart' s rate with exercise, are also available.
These marvels of electronic miniaturisation are keeping many people alive, and giving many more a much better quality of life.
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