Medical Questions » Heart Questions » Question No. 502
| Question: | What causes the heart to miss a beat now and then? Is it dangerous? |
| Answer: | If a piece of heart muscle is taken from the body and kept alive in a nutrient solution, it will spontaneously conrract at about 40 beats per minute.
There is an area near the top of the heart that is made from a complex network of nerves. This is the natural pacemaker of the heart, and it sends electrical signals to the heart muscle to contract at faster rate of approximately 70 beats a minute. This pacemaker is itself controlled by nerves running to the brain, so that anxiety and exercise can cause the heart to beat faster.
Certain chemicals in the blood stream can also act on the pacemaker, and the heart muscle itself, to alter the rate at which the heart contracts. It is therefore a very complex process.
The occasional dropped (missed) heart beat is due to a blockage of the nerve signal to the heart muscle, a lack of signal from the pacemaker, chemical disturbances in the body and many other factors. Alcohol, smoking, drugs, caffeine, high blood pressure and several diseases can all cause missed heart beats.
If the dropped beats occur only once every minute or so, there is no cause for concern, as this is a common phenomenon, particularly in older people. If you find that every third or fourth beat is being missed, you should be under regular medical care and probably on medication. Patients with problems within these extremes should discuss the matter further with their doctor. S/hc will almost certainly perform an ECG (heart electrical test) and probably order blood tests to exclude any serious disease. The treatment will depend on the result of these tests.
Missed heart beats are not in themselves dangerous, unless they become very frequent.
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