6th March 2024

Diagnosis

History and clinical examination are important in the initial assessment of any patient who presents with an arrhythmia. Their past medical history (e.g., Sarcoidosis causing complete heart block, a background of bipolar affective disorder requiring lithium therapy) is particularly relevant and may help reveal the underlying aetiology for the bradycardia. Observations, including temperature readings, may reveal hypothermia as the underlying culprit. Other baseline investigations include blood tests such as thyroid function, troponin in the event of accompanying chest pain or a suspicion of ischaemia, and venous blood gas to rule out acidosis.

The specific rhythm can be identified on a 12-lead ECG or through more prolonged monitoring if bradycardia is intermittent. An echocardiogram is recommended to rule out any structural causes for the underlying arrhythmia. Further imaging may be warranted, such as cardiac CT or MRI. Electrophysiology studies have a limited role in bradycardias and are usually reserved for measuring conduction delay in the His-Purkinje system in patients with suspected AV conduction abnormalities.