Performance of heart rhythm analysis during chest compressions in out-of-hospital cardiac arrest

This study aims to validate a shock advisory system in automated external defibrillators (AEDs) dedicated for ECG analysis during chest compressions (CC), guiding the rescuer to stop CC for rhythms which should be terminated by a defibrillation shock and to continue CC for non-shockable rhythms. The test-validation on a large database of out-of-hospital cardiac arrest interventions shows that the performance can be improved by increasing the duration of analysis. The combination of 3 successive analyses (delaying the decision to 14s after start of analysis) achieves sensitivity of 89.4% (135/151) - ventricular fibrillations, specificity of 98.7% (73/74) - normal sinus rhythms, 81.2% (1357/1671) - asystoles, 89.6% (566/632) - other non-shockable rhythms. Several examples are shown to illustrate the reconstructed ECG during CC that can be visually interpreted with certainty. Improving specificity of ECG analysis during CC is of tremendous importance preventing against frequent false positive interrupting the rescuer and the patient CC-treatment.