Diagnostic Accuracy of Commercially Available Automated External Defibrillators

Background Although automated external defibrillators ( AED s) have contributed to a better survival of out‐of‐hospital cardiac arrests, there have been reports of their malfunctioning. We investigated the diagnostic accuracy of commercially available AED s using surface ECGs of ventricular fibrillation ( VF ), ventricular tachycardia ( VT ), and supraventricular tachycardia ( SVT ). Methods and Results ECGs( VF 31, VT 48, SVT 97) were stored during electrophysiological studies and transmitted to 4 AED s, the LifePak CR Plus ( CR Plus), HeartStart FR 3 ( FR 3), and CardioLife AED ‐2150 ( CL 2150) and ‐9231 ( CL 9231), through the pad electrode cables. For VF , the CL 2150 and CL 9231 advised shocks in all cases, and the CR Plus and FR 3 advised shocks in all but one VF case. For VT s faster than 180 bpm, the ratios for advising shocks were 79%, 36%, 89%, and 96% for the CR Plus, FR 3, CL 2150, and CL 9231, respectively. The FR 3 and CR Plus did not advise shocks for narrow QRS SVT s, whereas the CL 9231 tended to treat high‐rate tachycardias faster than 180 bpm even with narrow QRS complexes. The characteristics of the shock advice for the FR 3 differed from that for the CL 9231 (kappa coefficient [κ]=0.479, P <0.001), and the CR Plus and CL 2150 had characteristics somewhere between the 2 former AED s (κ=0.818, P <0.001). Conclusions Commercially available AED s diagnosed VF almost always correctly. For VT and SVT diagnoses, a discrepancy was evident among the 4 investigated AED s. The differences in the arrhythmia diagnosis algorithms for differentiating SVT from VT were thought to account for these differences.