Two Clocks, One Failing Pulse

You are dispatched to a 72-year-old man with sudden dizziness and near-syncope. He is sitting on the floor, pale and diaphoretic, with no associated injury.

Estimated weight 80 kg. History: ischaemic heart disease, hypertension and type 2 diabetes. He takes bisoprolol 2.5 mg daily and denies an additional dose. Airway patent; RR 20/min; SpO₂ 91% on room air; pulse 31/min, regular and weak; BP 78/46 mmHg; CRT 4 seconds; cool clammy skin; GCS 14 with mild confusion; BGL 6.4 mmol/L; temperature 36.7°C.