Patients in VF/pulseless VT should receive one shock followed by two minutes of CPR. If they are witnessed having the cardiac arrest and are monitored (e.g. coronary care unit, critical care unit, catheter laboratory) then they should receive a maximum of three successive shocks instead. Chest compressions would then follow and CPR would be continued for 2 minutes.
Adrenaline 1mg IV and Amiodarone 300mg IV are given once compressions restart following three shocks for shockable rhythms (VT/pulseless VF). This is then followed by adrenaline 1mg IV after alternate shocks (every 3-5 minutes).
Adrenaline 1mg IV is also given as soon as venous access is achieved for non-shockable rhythms (pulseless electrical activity/asystole) which would be done alongside CPR. Pulseless electrical activity is a cardiac arrest in which there is electrical activity (other than ventricular tachycardia) which would normally have an associated pulse. Asystole is a cessation of any electrical and mechanical heart activity.
Ventricular tachycardia
Hypokalemia is the most important cause of ventricular tachycardia followed by hypomagnesaemia. Severe hyperkalemia may cause VT in those with underlying structural problems but hypo is most significant.
Supraventricular tachycardia
- Vagal manoeuvers
- If they don’t work IV adenosine
Polymorphic ventricular tachardia
- Subtype of this is torsades de pointes - precipitated by prolongation of the QT interval
- IV magnesium
Broad complex tachycarida
- DC cardioversion
- IV Amiodarone if adverse features not present