What is bradycardia (slow heart rate)?

Bradycardia is a slow heart rate (less than 60 beats per minute). Bradycardia can be present in otherwise normal individuals and is common in well-trained athletes and in most people during deep sleep. If it presents no symptoms, it usually doesn’t require treatment. However, with symptoms such as fainting (syncope), chest pain (angina), heart failure and high blood pressure, it should be treated.

Bradycardia refers to a slow heartbeat that is less than 60 beats per minute. If you are physically fit, you may have a slow heart rate at rest, and this is perfectly normal for you. But a heart rate lower than 60 beats a minute at rest may indicate a more serious problem for someone who is not physically fit.

Sometimes bradycardia means that the heart is not pumping enough blood through the body. Types of bradycardia include sick sinus syndrome and conduction blocks. With sick sinus syndrome, the sinus node, or the heart's natural pacemaker, isn't sending the electrical impulses properly. Sick sinus syndrome may be the result of scar tissue near the sinus node, which can result in stopping or disrupting the travel of the impulses. With a conduction block, the electrical impulses between the upper and lower sections of the heart may slow down or stop. Sometimes there are no symptoms when the impulse is blocked, yet other times you will experience bradycardia (slow heartbeat) or even skipped heartbeats.

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‚Äîand 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.

 

Bradycardia is the medical term often used to describe a slow heart rhythm. In a slow arrhythmia, the heart signals do not fire as they should, causing the heart rate to slow down.

Bradycardia usually refers to a resting heart rate under 60 beats per minute. While that may be low for someone who doesn't exercise, it isn't unusual for someone who does. (Spanish bicyclist Miguel Indurain, for example, once had his resting heart rate measured at 29 beats per minute!)

Your cardiologist might want you to have a stress test to see how your heart accelerates with exertion. An appropriate increase indicates that the sinus node (the heart's natural pacemaker) is working properly, which decreases worries about a low heart rate. A poor increase in heart rate with exertion, whether the resting heart rate is slow or fast, suggests the sinus node is failing and a pacemaker may be needed.