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A 78-year-old man is brought to the emergency department after collapsing while walking upstairs. His wife witnessed the event: he suddenly dropped to the ground without warning, was unresponsive for approximately 20 seconds, and recovered fully within a couple of minutes. He did not bite his tongue and was not incontinent. He has a 10-year history of hypertension, type 2 diabetes, and a myocardial infarction 5 years ago. His medications include ramipril, aspirin, atorvastatin, metformin, and doxazosin (started 2 weeks ago for nocturia).
On examination: pulse 36/min regular, BP 96/60 mmHg lying (no significant postural change), JVP not raised, no murmur, no focal neurology. 12-lead ECG shows a broad QRS (132 ms) with right bundle branch block and left anterior fascicular block, and intermittent drop-out of P-wave conduction. Capillary glucose is 5.6 mmol/L.
Questions
a) What is the most likely diagnosis, and give two ECG features that support it? (2 marks)
The most likely diagnosis is cardiac syncope due to intermittent high-grade atrioventricular (AV) block in the setting of bifascicular block (right bundle branch block + left anterior fascicular block). Supporting ECG features: (i) bifascicular block (RBBB + LAFB) indicates extensive His–Purkinje disease; (ii) intermittent drop-out of P-wave conduction indicates second-degree (likely Mobitz II) or higher AV block — a recognised cause of Stokes–Adams attacks. The bradycardia (36/min), exertional onset (a tachycardia-dependent block), absent prodrome, and rapid complete recovery are all consistent with cardiac syncope.
b) List four RED-FLAG features that, in any patient with syncope, mandate admission for telemetry and cardiology work-up. (2 marks)
- Syncope during exertion or while supine.
- No prodrome / palpitations immediately before the collapse.
- Abnormal ECG (any conduction disease — bifascicular block, Mobitz II, complete heart block, sinus pause >3 s, channelopathy patterns).
- Known structural heart disease (prior MI, cardiomyopathy, valvular disease) OR family history of sudden cardiac death under 40.
This patient meets at least three (exertional, no prodrome, abnormal ECG with bifascicular block + intermittent AV block, and prior MI).
c) Reproduce the San Francisco Syncope Rule (CHEAT) and interpret it for this patient. (2 marks)
The San Francisco Syncope Rule flags high-risk if any one is present:
- C — history of Congestive heart failure
- H — Haematocrit under 30%
- E — abnormal ECG (any new or not-previously-documented change)
- A — Abnormal vital sign: SBP under 90 mmHg at triage OR shortness of breath
- T — Trouble breathing
This patient has an abnormal ECG (bifascicular block + intermittent AV block) — he is SFSR-positive and requires admission for monitoring and work-up. Sensitivity for serious 7-day outcomes is approximately 96–98%.
d) Outline the immediate (resuscitation) and definitive management. (4 marks)
Immediate / resuscitation:
- ABCDE; IV access; continuous ECG monitoring on a telemetry bed.
- Bloods: FBC, U&E, troponin, glucose, β-hCG (not applicable here).
- Symptomatic bradycardia: atropine 0.5 mg IV, repeated every 3–5 minutes to a maximum of 3 mg; if ineffective, transcutaneous pacing (with analgesia/sedation) then transvenous pacing.
- Review and stop the doxazosin (alpha-blocker contributing to hypotension) and hold/adjust the ramipril.
Definitive:
- Urgent permanent pacemaker — bifascicular block with unexplained syncope and documented intermittent high-grade AV block meets the class I indication for pacing.
- Echocardiogram to assess LV function (post-MI, doxazosin effect) and exclude other structural causes.
- Post-pacing, driving advice per DVLA/RTO: Group 1 — 4 weeks off after successful treatment; longer if untreated.
- Address modifiable risk factors (medication review, glycaemic/BP control, secondary prevention of ischaemic heart disease).