Ventricular fibrillation recorded and analysed within an area the size of a mobile phone: could it enable cardiac arrest recognition?

BACKGROUND: Recognition of out-of-hospital-cardiac arrests (OHCAs) at emergency medical communication centres is based on questions of OHCA symptoms, resulting in 50-80% accuracy rates. However, OHCAs might be recognized more promptly using 'rhythm-based' recognition, whereby a victim's cardiac rhythm is recorded with mobile phone technology that analyses and transmits recordings to emergency medical communication centres for further interpretation. OBJECTIVE: To examine whether the quality of normal cardiac rhythm and the rhythm with the best prognosis in OHCA, ventricular fibrillation (VF), is sufficient for 'rhythm-based' OHCA recognition when recorded within a mobile phone-sized device. PATIENTS AND METHODS: mid-sternum within an area the size of a mobile phone and analysed by automated external defibrillator (AED) software and two cardiologists. The rhythms were categorized as shockable or nonshockable. The cardiologists assessed the quality of the recordings. RESULTS: The AED software correctly analysed all normal rhythms and 15 of 22 VF rhythms. The VF duration was too short for automatic detection in seven cases. The cardiologists analysed all the normal rhythms and VF sequences correctly and graded them as high quality. CONCLUSION: The recordings of normal ECG rhythm and VF within an area the size of a mobile phone are of sufficient quality and could be used in 'rhythm-based' OHCA recognition. The VF period was too short for an accurate analysis by the AED software in some cases.