Bradycardia (Slow Heart Rate)

Having bradycardia means that your heart beats very slowly. For most people, a heart rate of 60 to 100 beats a minute while at rest is considered normal. If your heart beats less than 60 times a minute, it is slower than normal.

Sometimes bradycardia is normal. For example, healthy young adults and well-trained athletes often have resting heart rates of less than 60 beats a minute.

Bradycardia is abnormal when the heart's normal pacemaker does not work correctly or when the normal electrical system of the heart has been damaged. Abnormal bradycardia (also called bradyarrhythmia, sick sinus syndrome, or sinus node dysfunction) is an abnormally slow heart rate that is caused by certain medical conditions-including heart disease, hypothyroidism, and electrolyte imbalances-and some medicines. In severe forms of bradycardia, the heart beats so slowly that it does not pump enough blood to meet the body's needs. This can be life-threatening.

How bradycardia is treated depends on what is causing it. Treatment also depends on the symptoms. If bradycardia does not cause symptoms, it usually is not treated. A pacemaker is often needed to restore a normal heart rate.