THE CONTEXT
Sinus bradycardia and sinus tachycardia have distinct listed pathological causes. Sinoatrial disease can produce several bradyarrhythmias, tachyarrhythmias and conduction abnormalities.
Causes of sinus bradycardia
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Cardiac causes include myocardial infarction and sinus node disease, also called sick sinus syndrome.
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Other causes include hypothermia, hypothyroidism, cholestatic jaundice and raised intracranial pressure.
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Listed causative drugs are beta-blockers, digoxin and verapamil.
Causes of sinus tachycardia
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Listed causes include anxiety, fever, anaemia and heart failure.
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Endocrine causes include thyrotoxicosis and phaeochromocytoma.
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Beta-agonists are listed as a drug cause.
Common features of sinoatrial disease
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Bradycardic features include sinus bradycardia and sinoatrial block, described as sinus arrest.
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Paroxysmal atrial fibrillation and paroxysmal atrial tachycardia may occur.
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Atrioventricular block is also a common feature.