Table 1 Common causes of sinus node dysfunction

Drugs (beta blockers, lithium, calcium channel blockers, digoxin, clonidine, amiodarone, propafenone, parasympathomimetic drugs)

Myocardial infarction

Severe hypoxia

Hypothyroidism

Hypothermia

Fibrodegenerative changes of sinus node

Vomiting

Vasovagal syncope

Carotid sinus stimulation

Raised intracranial pressure