Often classified by the site of the disorder -

• SA node dysfunction (impulse formation disorder: reduced automaticity)

• AV node conduction disorders

• What are the subtypes of SA node dysfunction?

• What are the subtypes of AV conduction disturbance?

• Sinus Bradycardia:

• Sinus pause (arrest)

• 1st degree AV block

• 2nd degree AV block (Morbitz T1/Wenckebach)

• 2nd degree AV block (Mobitz type 2)

• 3rd degree AV block

Management for bradycardias/AV node blocks

Stable:

• observe, review meds

Unstable/risk of asystole (shock, syncope, MI, pulmonary oedema/HF):

FIRST LINE - Atropine 500 mcg IV (Atropine works by inhibiting parasympathetics, so side effects are dry eyes, constipation, pupil dilatation, urinary retention)

IF NO IMPROVEMENT -