Advanced life support (ALS) involves the use of specialised equipment and drugs in an effort to restore spontaneous circulation and is the definitive treatment for all cardiac arrests. Once cardiac arrest is diagnosed, basic life support (BLS) should normally be commenced while equipment is being gathered, although, in certain areas such as coronary care units, defibrillation should be considered immediately without BLS. BLS should not cause a delay in defibrillation.

A single precordial thump should be considered in a witnessed or monitored cardiac arrest. It is a sharp blow to the lower sternum which transfers around 20 J of kinetic energy to the myocardium, which may restore sinus rhythm in some instances of ventricular fibrillation (VF) (fig 1) or pulseless ventricular tachycardia (VT) (fig 2).

In cardiac arrest, two main disorders of cardiac rhythm are recognised (fig 3): ventricular …