A fatal combination of situs inversus, pregnancy and cardiac arrest treated with an automated external defibrillator

The AED delivered wrongful shocks, probably because the tachyarrhythmia with QRS complexes of low amplitude was considered to be ventricular fibrillation. Evidence for this comes from the ECG strips from the first AED rhythm analysis, clearly showing QRS complexes of a similar shape and amplitude, but at a lower rate. Furthermore, these small QRS complexes were continuously found from the start of the resuscitation attempt until the fourth shock (data not shown). This case illustrates that the specificity of shock/noshock decisions by the AEDs is not 100% [1, 2]. Cardiologists should also be aware that AED sensitivity figures are only within a 90–95% range, and that external artefacts during the analysis process (such as chest compressions) decrease the accuracy significantly. This implies that shock/no-shock decisions should be scrutinised before being used for diagnostic/therapeutic decision making and prognostication.