Final answer:
Nocturnal bradycardia or conduction disturbance can be associated with extracardiac conditions such as metabolic disorders, pathologies of the endocrine system, neurological disorders, autoimmune pathologies, over-prescription of beta blocker drugs, recreational drug use, or prolonged bed rest.
Step-by-step explanation:
Nocturnal bradycardia or conduction disturbance can be associated with extracardiac conditions such as metabolic disorders, pathologies of the endocrine system, neurological disorders, autoimmune pathologies, over-prescription of beta blocker drugs, recreational drug use, or prolonged bed rest. These external factors can affect the heart's electrical conduction system and lead to abnormal heart rates during sleep. Treatment for nocturnal bradycardia or conduction disturbance depends on identifying the underlying cause and may include supplemental oxygen.