Slow heart rate (less than 50 beats per minute)

A heart rate of less than 50 beats per minute is usually considered a slow heart rate (bradycardia). Well-trained athletes often have slow heart rates, but this is not normal for most people.

A slow heart rate can cause lightheadedness, fainting, chest discomfort, or shortness of breath because not enough blood is being pumped to the rest of the body. A slow heart rate that is not causing other symptoms usually is not serious. Slow heart rates that cause other symptoms are serious and need to be evaluated by a health professional. A slow, irregular heart rate that is different than your normal heart rate needs to be reported to your health professional immediately.

If you have heart disease, heart failure, or a history of heart attack, it is especially important to understand how serious a slow heart rate can be. This is especially true if it occurs with shortness of breath when you are resting or after mild exertion. Call your health professional if you have a sudden change in your usual heart rate or rhythm.