Pathologic bradycardias are caused by disorders of impulse generation (impaired automaticity at [[SA node]]), impulse conduction ([[heart block]]) or [[escape pacemaker]]s and rhythms. Bradycardia can be underlain by several causes, which are best divided into cardiac and non-cardiac causes or based on the location of the abnormality. Non-cardiac causes are usually secondary, and can involve recreational drug use, [[endocrine]] disorders ([[hypothyroid]]), [[electrolyte]] imbalance ([[hyperkalemia]]), autonomic reflexes; situational factors (prolonged [[bed rest]]); infections [[lyme disease]], medications, and [[autoimmune|autoimmunity]] disorders. Cardiac causes include acute or chronic [[ischemic heart disease]], vascular [[heart disease]], [[valvular heart disease]], or degenerative primary electrical disease (fibrosis and calcification of the [[sinus node]] and [[conduction system]]).
==Causes==
==Causes==
===Common Causes of Bradycardia===
===Common Causes of Bradycardia===
Pathologic bradycardias are caused by disorders of impulse generation (impaired automaticity at [[SA node]]), impulse conduction ([[heart block]]) or [[escape pacemaker]]s and rhythms. Bradycardia can be underlain by several causes, which are best divided into cardiac and non-cardiac causes. Non-cardiac causes are usually secondary, and can involve recreational drug use, [[endocrine]] disorders ([[hypothyroid]]); [[electrolyte]] imbalance ([[hyperkalemia]]); autonomic reflexes; situational factors (prolonged [[bed rest]]); infections [[lyme disease]], medications, and [[autoimmune|autoimmunity]] disorders. Cardiac causes include acute or chronic [[ischemic heart disease]], vascular [[heart disease]], [[valvular heart disease]], or degenerative primary electrical disease (fibrosis and calcification of the [[sinus node]] and [[conduction system]]).
==Causes According to the Location of the Abnormality==
==Causes According to the Location of the Abnormality==
Pathologic bradycardias are caused by disorders of impulse generation (impaired automaticity at SA node), impulse conduction (heart block) or escape pacemakers and rhythms. Bradycardia can be underlain by several causes, which are best divided into cardiac and non-cardiac causes or based on the location of the abnormality. Non-cardiac causes are usually secondary, and can involve recreational drug use, endocrine disorders (hypothyroid), electrolyte imbalance (hyperkalemia), autonomic reflexes; situational factors (prolonged bed rest); infections lyme disease, medications, and autoimmunity disorders. Cardiac causes include acute or chronic ischemic heart disease, vascular heart disease, valvular heart disease, or degenerative primary electrical disease (fibrosis and calcification of the sinus node and conduction system).
Causes
Common Causes of Bradycardia
Causes According to the Location of the Abnormality
↑Pagon RA, Bird TD, Dolan CR; et al. PMID20301600. Missing or empty |title= (help)CS1 maint: Explicit use of et al. (link) CS1 maint: Multiple names: authors list (link)