Mon25October0757PM 6

A 37-year-old male is brought to the Emergency department having suffered a collapse at home.

Whilst cooking breakfast he had become dizzy and collapsed to the floor. He lost consciousness for 20 seconds. His wife called the ambulance. On arrival his GCS was 15/15, pulse 37 regular, BP 105/60 mmHg.

On arrival at the Emergency department he started to feel dizzy and his BP dropped to 92/65 mmHg. His pulse was 35 BPM and regular. An ECG demonstrated a narrow complex regular bradycardia with no P waves visible.

The Emergency department doctor administered 500 micrograms of atropine with no improvement. He remained alert and orientated. He had a large, well healed sternotomy scar and was on powerful immunosuppressants, his wife informs you he had a cardiac transplant three years previously.

You called the cardiology registrar who was busy for another 15 minutes with a primary PCI call.

The cardiology registrar asked to try another treatment before he came down to see the patient.

What is the most likely treatment suggested by the cardiology registrar?

(Please select 1 option)

Glycopyrrolate

Repeated doses of atropine at 500 mcg per dose

Glucagon

Repeated doses of atropine at 1 mg per dose

Slow intravenous infusion of theophylline Correct

Explanation

This question is designed to test knowledge of the management of bradycardias.

The scenario describes a typical history of a syncopal event secondary to a bradycardia. The key to its management is the recognition of any adverse factors (shock, syncope, heart failure or ischaemia). If none are present and patient is not at risk of asystole, the patient should be observed in the first instance.

The key part of this scernario is history of a cardiac transplant The pharmacotherapy of bradycardias is different for this group of patients. This is because the transplanted heart is denervated.

Therefore there is no place for atropine, even at higher doses, hence repeated doses of atropine at 500 mcg per dose or at 1 mg per dose are incorrect.

Glycopyrrolate is an antimuscirinc agent and has a similar mechanism of action to atropine, hence glycopyrrolate is incorrect.

Glucagon can be useful if there is a suggestion of betablocker overdose, this could be the case here but we are not told the patient is on a beta blocker.

The Resuscitation Council (UK) guidelines suggest using theophylline as a slow intravenous infusion (100-200 mg).

Temporary pacing would also be an appropriate course of action but only if there is little delay. The patient is alert and therefore medical treatment could be tried first.

Answer Statistics

1

14%

2

8%

3

40%

4

4%

5

36%

Times answered: 265