5th May 2025

Aetiology

The common causes of bradyarrhythmias are summarised in Table 1. In elderly patients, ischaemic heart disease and age-related fibrosis of the cardiac conducting system are common causes of bradyarrhythmias. In younger patients, congenital and autoinflammatory causes such as cardiomyopathies, sarcoidosis and infections are more commonly found. In approximately one quarter of patients who present to the emergency department (ED) with bradycardia, adverse drug reaction or intoxication is identified. For purposes of simplicity, we will break down the causes into ‘cardiac’ and ‘non-cardiac’ causes and explore the common cardiac causes of bradycardia.