Atrioventricular block 3rd degree
Last modified: 13 March 2022, 8:32:15 AM AEDT
Gems / Priorities1 / 8
- 3D-AVB is often an emergency
- Complete Heart Block
Definition / diagnostic criteria2 / 8
Aetiology / Causes / Risk Factors3 / 8
- Cardiac
- IHD, cardiomyopathy
- Neuro
- ⬆vagal tone
- Renal
- ⬆K
- Drugs
- BB, digoxin
- Trauma
- Cardiac surgery
- Other
- degenerative
- congenital
Pathophysiology4 / 8
- impaired AVN conduction
- complete AVN block = complete AV dissociation = independent atrial and ventricular activity
- atria and ventricles controlled by separate pacemakers
- ventricular rate typically < 45 BPM
- dissociation of P wave and QRS complex
- QRS is not from P wave
- QRS is an escape rhythm from ventricular pacemaker = wide complex ventricular escape rhythm
- P wave = 60-80 bpm
- QRS = 30-40 bpm
Signs / Examination5 / 8
- ⬇BP
- wide pulse pressure
- canon JVP waves
Management6 / 8
- cardiac pacing
- transcutaneous
- temporary wire
- isoprenaline / adrenaline infusion
Anaesthetic considerations7 / 8
- Pre-op
- Intra-op
- Post-op