Transcutaneous pacing (TCP)
Transcutaneous pacing (external pacing) is a temporary, emergency measure to restore heart rate and perfusion in patients with unstable or symptomatic bradyarrhythmia that has not responded to initial medical therapy (eg atropine ± isoprenaline). It is a bridge to definitive therapy (transvenous pacing or permanent pacemaker) and should be used alongside correction of reversible causes and early specialist escalation (Resuscitation Council UK; NICE TA88).
Indications and role
- Indicated for haemodynamically significant bradycardia refractory to pharmacological measures, or when immediate pacing is required and transvenous access is not immediately available (Resuscitation Council UK).
- Use TCP as a temporary stabilisation measure while arranging cardiology/critical care support and definitive pacing.
- Not a long‑term solution; follow local cardiology pathways and NICE guidance for permanent device decisions (NICE TA88).
- Limited role in paediatrics: bradycardia secondary to hypoxia/respiratory failure in children is usually treated by airway/ventilation measures; TCP is rarely helpful for hypoxic/asystolic bradycardia in infants/children (Resuscitation Council UK).
Physiology - electrical vs mechanical capture
- Electrical capture: a pacing stimulus (spike) on the monitor that is immediately followed by a QRS complex.
- Mechanical capture: resultant effective ventricular contraction demonstrated by a palpable central pulse and improved blood pressure/perfusion.
- Always confirm mechanical capture - electrical capture alone does not guarantee circulation.