Final answer:
Bradycardia is a condition in which the resting heart rate drops below 60 beats per minute. It can be caused by inherent factors or external causes. Treatment involves identifying the underlying cause and may include supplemental oxygen.
Step-by-step explanation:
Bradycardia is a condition in which the resting heart rate drops below 60 beats per minute. The underlying causes of adult bradycardia can be either inherent or external to the heart. Inherent causes include abnormalities in the SA or AV nodes, which may require a pacemaker if the condition is serious. External causes can range from metabolic disorders and pathologies of the endocrine system to neurological disorders and drug use. The treatment of adult bradycardia involves identifying the underlying cause and may include supplemental oxygen.