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Bradycardia and its causes

Bradycardia is defined as pulse rate below 60 per minute.
This  is commonly found in the following conditions
Causes of bradycardia
Commonest cause of bradycardia are regular athletic training and myxoedema
Causes of physiological bradycardia
  • Athletes
  • Sleep
Causes of pathological bradycardia
  • Myxoedema
  • Obstructive jaundice
  • Raised intraocular pressure
  • Raised intracranial tension(cushings phenomenon)
  • Complete Heart blocks
  • Sick sinus syndrome
  • Drugs (beta blockers, verapamil,diltiazem, digoxin).
  • Severe hypoxia
  • Hypothermia
What is  Sinus bradycardia?
In sinus bradycardia the pulse rate is below 60 per minute and  the impulse is originating form the
SA node. The common causes are  all the causes mentioned above in bradycardia except complete heartblock (in CHB. idioventricular rhythm occurs at the rate of 36 per minute)'
What are the causes of bradycardia associated with convulsions ?
  • Complete heart block (Stokcs-Adams syndrome).
  • Increased intracranial tension due to meningoencephalitis. brain tumour,CVA
  • Prior to development of coma in myxoedema.