• ventricular standstill

Many accident and emergency (A&E) departments use the rhythm display of defibrillators to perform cardiac monitoring in critically ill patients, as do ambulance personnel and an increasing number of general practitioners. It has previously been recognised that ventricular fibrillation may exist with very low or event absent amplitude, with the patient appearing to be in asystole on the monitor.¹ To help overcome this problem modern defibrillators have an automatic gain feature that will increase the amplitude of low amplitude signals. We report a case where the failure to recognise that this increase in gain had occurred resulted in a delay in the recognition of periods of ventricular standstill in a child.