Bradycardia is a condition that is commonly called low heart rate. A normal heart rate for a resting adult is usually 60 to 100 beats per minute. Any heart rate below this is considered too low. Sometimes this condition is caused by certain health problems, especially heart problems, or medications. Other times, it may not be a problem at all, just a sign of good health.
When an individual has a low heart rate, one of the more common causes is an underlying heart problem. A heart attack or other trauma to the heart, for example, can cause problems with the heart's natural pacemaker. This can sometimes cause a person's heart to beat too fast or too slow.
Many times, patients with this type of problem must have an artificial pacemaker. These tiny electronic devices are surgically implanted into the chest. This device is then hooked to the heart, and electric impulses cause the heart to beat in a regular rhythm.
Patients with certain thyroid problems may also suffer from a low heart rate. Hypothyroidism, for example, occurs when the thyroid gland produces an insufficient amount of thyroxine. This is the hormone that is responsible for regulating a person's metabolic rate. Low levels of this hormone can cause a low heart rate.
Chemical imbalances, such as an electrolyte imbalance, in a person's body can also cause the heart to beat too slowly. Hyperkalemia occurs when a person's blood has too much potassium. This can cause the muscles in the heart to stop working properly, which can lead to bradycardia, and in some cases, heart failure. A massive dose of potassium is injected into prisoners sentenced to die by lethal injection.
Bradycardia may also be a side effect of some medications. Ironically, most of the medications that can produce this side effect are the same medicines used to treat other heart problems. Beta-blockers, for example, are used to treat high blood pressure, but they can also cause a dangerously low heart rate in some individuals.
In some individuals, a low heart rate is actually a sign of good health and fitness. People who exercise regularly, including trained athletes, typically have a lower heart rate than more sedentary individuals. This occurs because active individuals usually have much healthier hearts.
A person who has bradycardia should usually only be concerned if he experiences negative symptoms. Some signs of medical problem pertaining to this condition include dizziness and fainting, along with weakness, fatigue, and chest pains.