It depends. Bradycardia indicates that the heart rate is too slow (< 60 BPM in adults). It may be associated with a normal electrical impulse (such as sinus bradycardia in a well-trained athlete or during sleep) or an arrhythmia (abnormal electrical impulse). Some of the more common abnormal rhythms associated with bradycardia include atrioventricular block, sick sinus syndrome, and junctional rhythm.
Many. 1. Medications 2. High vagal tone as is present in lance armstrong 3. Conduction system disease 4. Infections/endocarditis with a ring abscess 5. Sick sinus syndrome 6. Atrio-ventricular conduction delay 7. Abnormal electrolytes (high potassium 8. Kindey failure.
Medication. A slow heart rate can be normal in fit individuals at rest. Many medications, notably beta blockers, slow the heart rate. A slow heart rate can also be due to disease of the av node, which conducts impulses from the atria to the ventricles. This can be due to scarring from heart attack or aging, and is seen in some infections such as lyme disease and chagas disease.
Bradycardia. Sinus bradycardia.