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Unexplained syncope — SCE Geriatric Medicine MCQ

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HardCardiovascular in Older AdultsUnexplained syncopeSCE Geriatric Medicine

An 83-year-old man is assessed after three episodes of abrupt transient loss of consciousness over 8 months. The latest episode caused a facial laceration. Each occurred while standing, without prodrome, and recovery was rapid and complete. A witness reports no prolonged limb jerking, lateral tongue-biting or post-event confusion. There is no relationship to exertion. He has no history of stroke or transient ischaemic attack. Cardiovascular and neurological examinations are normal, with no carotid bruit. Lying and 3-minute standing blood pressures are 146/78 mmHg and 140/76 mmHg respectively. A 12-lead ECG shows sinus rhythm with normal PR and QRS intervals. Which investigation strategy is most appropriate?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — Perform carotid sinus massage under controlled monitoring; if nondiagnostic, insert an implantable event recorder

Explanation lettering: D = shown as B · E = shown as D · B = shown as E

This is recurrent unexplained syncope in a person aged over 60, with abrupt onset, injury and no convincing epileptic, orthostatic or structural cardiac features. NICE recommends carotid sinus massage as a first-line investigation in people aged 60 or older with unexplained syncope. It must be undertaken in a controlled environment with ECG recording and resuscitation equipment. Carotid sinus syncope requires reproduction of symptoms with marked bradycardia, asystole or hypotension; an asymptomatic haemodynamic response is insufficient. If carotid sinus massage is nondiagnostic, ambulatory ECG is required. His events occur much less frequently than once every 2 weeks, so an implantable event recorder offers substantially greater diagnostic yield than a Holter or short external recorder. B uses monitoring of inadequate duration and incorrectly places tilt testing before definitive ambulatory ECG. C is attractive because reflex syncope remains possible, but NICE advises against tilt testing before ambulatory ECG in unexplained syncope. D lacks an indication: examination and ECG provide no evidence of structural heart disease, and 7-day monitoring is poorly matched to the event frequency. E would be appropriate only if the history suggested epilepsy; routine electroencephalography is not indicated here, and a patient-activated recorder may fail to capture sudden syncope.

Reference: Transient loss of consciousness ('blackouts') in over 16s: Recommendations (Last updated 21 November 2023) — https://www.nice.org.uk/guidance/cg109/chapter/Recommendations