Resumption of chest compressions after successful defibrillation and risk for recurrence of ventricular fibrillation in out-of-hospital cardiac arrest.

TitleResumption of chest compressions after successful defibrillation and risk for recurrence of ventricular fibrillation in out-of-hospital cardiac arrest.
Publication TypeJournal Article
Year of Publication2014
AuthorsConover Z, Kern KB, Silver AE, Bobrow BJ, Spaite DW, Indik JH
JournalCirc Arrhythm Electrophysiol
Volume7
Issue4
Pagination633-9
Date Published2014 Aug
ISSN Number1941-3084
KeywordsAged, Arizona, Defibrillators, Electric Countershock, Electrocardiography, Emergency Medical Services, Female, Heart Massage, Humans, Kaplan-Meier Estimate, Male, Middle Aged, Out-of-Hospital Cardiac Arrest, Predictive Value of Tests, Recurrence, Retrospective Studies, Risk Assessment, Risk Factors, Time Factors, Treatment Outcome, Ventricular Fibrillation
Abstract

BACKGROUND: Prior investigation of out-of-hospital cardiac arrest has raised the concern that ventricular fibrillation (VF) recurrence may be triggered by chest compression (CC) resumption. We investigated predictors of VF recurrence after defibrillation, including timing of CC resumption.

METHODS AND RESULTS: Patients with witnessed out-of-hospital cardiac arrest and initial rhythm of VF from an Utstein-style database were analyzed. For each shock that defibrillated VF, CC resumption and VF recurrence times were determined. Shocks were classified according to postshock rhythm. Factors (age, sex, time from dispatch to monitor/defibrillator application, and CC resumption) that could predict VF recurrence were analyzed. CC resumption was categorized into groups: CC1, 1 to 5 seconds; CC2, 6 to 10 seconds; CC3, 11 to 30 seconds; and CC4, >30 seconds. Eighty-eight subjects were analyzed, with a total of 285 shocks, with 226 shocks that achieved asystole (n=102), organized rhythm (n=120), or monomorphic ventricular tachycardia (n=4). After a successful shock, CC resumption occurred at a median (interquartile range) of 8 (5-18) seconds. VF recurred after 166 shocks (74%) and recurred within 30 seconds in 69 shocks. There was no significant relationship between VF recurrence and factors analyzed including CC resumption time, nor stratified by postshock rhythm. The hazard ratios (HRs) for VF recurrence within 30 seconds for later CC groups (CC2, CC3, and CC4) relative to early CC resumption (CC1) were as follows: HR(CC2)=1.05 (P=0.9); HR(CC3)=1.75 (P=0.1); and HR(CC4)=0.67 (P=0.4).

CONCLUSIONS: VF recurrence within 30 seconds of a defibrillatory shock was not dependent on timing of CC resumption in patients with witnessed arrest and initial rhythm of VF.

DOI10.1161/CIRCEP.114.001506
Alternate JournalCirc Arrhythm Electrophysiol
PubMed ID25015946
Faculty Reference: 
Bentley J. Bobrow, MD, FACEP, FAHA
Daniel W. Spaite, MD