Anyone who experiences a slow heart rate, which is referred to as bradycardia, or symptoms associated with bradycardia, is advised to see a doctor, according to Mayo Clinic. Symptoms of bradycardia include a heart rate under 60 beats per minute, shortness of breath, dizziness, fatigue, weakness and chest pains.
For well-trained athletes and healthy young adults, a resting heart rate under 60 beats per minute is normally not a cause for concern, notes Mayo Clinic. The average adult should have a heart rate that is between 60 to 100 beats per minute. When the heart does not beat fast enough, it can deprive the brain and other organs of oxygen.