You have a slow heart rate. This is called bradycardia. At rest, the normal heart rate is between 60-100 beats per minute. A slow heart may cause weakness, dizziness, loss of consciousness, and shortness of breath. This gets worse when you are active.

The medical causes of bradycardia can include:

  • Heart and thyroid problems.

  • High potassium.

  • Side effects of some medicines.

Well-trained athletes may have heart rates as slow as 42 beats per minute. Evaluation of bradycardia may require an electrocardiogram (ECG), blood tests, and possibly other heart studies.

Bradycardia due to heart disease can be a serious problem. Damage to the heart's electrical system may require a temporary or permanent pacemaker. Beta-blocker drugs, digoxin, and other medicines used to control blood pressure and heart rhythms will also slow the heart. These medicines may need to be used in lower doses, or be stopped, if you have problems from the bradycardia.


  • You develop fainting, extreme weakness, shortness of breath, or fever.

  • You develop severe chest or abdominal pain, repeated vomiting, or dehydration.

  • You become sweaty and weak.


  • Understand these instructions.

  • Will watch your condition.

  • Will get help right away if you are not doing well or get worse.