The first step is to determine whether the patient has ANY of the life-threatening features or not:

• Shock – hypotension (SBP < 90 mmHg) and/or features of sympathetic compensationTachycardia cold pale skin, ↓ CRT symptoms of ↓ cerebral blood flow (confusion, ↓ GCS)
• Syncope – due to ↓ cerebral blood flow
• Myocardial ischaemia – chest pain and/or 12-ECG findings
• Heart failure – pulmonary oedema (LV failure) and/or raised JVP (RV failure)

Note this is the same as the peri-arrest tachycardia algorithm.

• 1^st line: atropine 500mcg IV (alternative: glycopyrrolate)
  • Repeat every 3-5 minutes, up to a maximum of 6 doses / 3mg
• If ineffective → consider 2^nd line drugs:
  • Isoprenaline
  • Adrenaline
• If ineffective → transcutaneous pacing Quick, non-invasive method to deliver electrical impulses to the heart via external electrode pads on the chest. Note it is not always reliable in achieving consistent cardiac capture, success rate varies from 50-80%, depending on various factors. Transcutaneous pacing is also uncomfortable for patients, often requiring sedation or analgesia.
• If ineffective → transvenous pacing Invasive method to deliver electrical impulses to the heart where pacing leads is inserted through a central vein (often subclavian or internal jugular vein) and advanced into the right ventricle. It is not as quick as transcutaneous pacing to set up, but is more comfortable and effective for longer-term use.

Assess risk of asystole:

• Recent asystole
• Second degree Mobitz II AV block
• Complete heart block with broad QRS
• Ventricular pause > 3 sec

Subsequent action:

• Yes → proceed as life-threatening features are present
• No → observe

Adult advanced life support Guidelines
ERC Guidelines 2021