Background: The early use of
automated external defibrillators (AEDs) can save lives by correcting lethal ventricular arrhythmias with minimal operator intervention. AED
shock advisements also play a role in termination of
resuscitation strategies. AED function is dependent on the accuracy of their
shock advisement algorithms, which may differ between manufacturers. We sought to compare the
shock advisement performance characteristics of several AEDs. Methods: We conducted a prospective, laboratory-based simulation study evaluating five commercially available AEDs from Cardiac Science, Defibtech, Medtronic, Philips, and Zoll.
Shock advisement performance was evaluated for eight ECG rhythms {
ventricular fibrillation (VF),
ventricular tachycardia (VT), toursades de pointes (TdP), sinus rhythm (SR),
atrial fibrillation (AF),
atrial flutter (AFL), idioventricular rhythm (IDV), and
asystole} that were generated using the SimMan Classic Manikin and the LLEAP Simulator software (Laerdal Medical Inc., Norway). We recorded
shock advisement decisions for each of the ECG rhythms three times per device.
Shock advisements were coded as discordant if a
shock was advised for a non-shockable rhythm or not advised for a shockable rhythm. Results: We analyzed 330 rhythm trials in total (66 per device), finding 28 (8.5%) discordant
shock advisements overall. Discordance ranged from 6% to 11% among the five AED models. VF rhythm variants were the most frequent (43%) source of discordant advisements. No shocks were advised for any of the sinus rhythms, AFL, AF with QRS > 40, IDV, or
asystole. Conclusions: Discordant
shock advisements were observed for each AED and varied between manufacturers, most often involving VF. There may be implications for termination of
resuscitation decision making.