Is hands-on defibrillation safe when using insulating gloves? A clinical trial

Abstract

Introduction: Surface electrocardiographic (ECG) changes in ventricular fibrillation (VF) waveform characteristics at its onset in patients experiencing cardiac arrest have not been quantified. The amplitude spectral area (AMSA)methodwas developed to analyze surface ECG VF amplitude and frequency characteristics and contains information related to VF rotor stability and myocardial viability. We aimed to characterize changes in AMSA at the onset of VF to gain insight into myocardial dynamics in patients with a wearable cardioverter defibrillator (WCD). Methods: Out of 30 patients randomly identified from a manufacturer-maintained registry, 25 patients (14 Male, 11 Female, Age=62±14 yr) were included. Remaining patients experienced either sustained monomorphic ventricular tachycardia or hadmotion artifact, precludingAMSAanalysis. Using theWCDECG, AMSA was calculated as the summed product of frequency and square root of power at that frequency from 2 to 48Hz with a continuous sliding 2.1 s Tukey window. The median time to shock for the WCD is 45 s. AMSA was calculated every 0.5 s and averaged every 1 s for up to 45 s after VF initiation. Results are presented as mean± standard error. Results: At onset of VF, AMSA was 33.6±3.3mVHz which decreased progressively to 23.4±2.2mVHz (p<0.01) after 45 sec of untreated VF (Fig. 1).