Automated external defibrillation: laboratory evaluation.

Twelve samples of ventricular fibrillation were fed into nine automated external defibrillator-pacemakers ( AEDP , "Heart Aid") of recent design. All the devices recognised and defibrillated ventricular fibrillation in seven of the samples within 30 sec. None of the devices reacted to two of the samples; in the remaining three there was inter-device variation ranging from an appropriate response to no response, as well as inappropriate pacing or delay in recognition and treatment. Poor recognition of some ventricular fibrillation waveforms with considerable inter-device variation limits the usefulness of this model. A new prototype responded more consistently and future models may be of value in community resuscitation. The difficulty of evaluating the diagnostic capability of AEDP devices in clinical use makes comprehensive laboratory testing essential prior to release.