Recurrence of Ventricular Fibrillation after Successful Conversion, May be Associated with Immediate Post-Shock Chest Compressions: A Case Report

Aims: Since 2005, cardiopulmonary resuscitation (CPR) guidelines advise immediately resuming CPR after a defibrillation shock to minimize CPR interruption. During resuscitation, the incidence of ventricular fibrillation (VF) recurrence is as high as 79%. The aim of this report is to present a case of VF recurrence induced by chest compressions (CCs) following successful defibrillation of VF and to discuss the possible mechanisms that could be linked to this observation.
Case Presentation: A 57 year-old female suddenly collapsed and upon initiation of CPR, VF was observed. The patient was treated with 6 CPR-defibrillation cycles according to the current guidelines, after which she converted to normal sinus rhythm (NSR), but died following 9 in-hospital days. The monitor rhythms strips throughout resuscitation reveal restoration of NSR after the 4th defibrillation, yet CCs were resumed 1.3 seconds post DC shock and refibrillation closely followed. The first compression was timed exactly on the peak of the first post-shock sinus beat followed by refibrillation.
Discussion: possible mechanisms for the observed phenomenon include: creation of a long-short activation sequence by electric stimulation of the ventricles leading to VF recurrence, sudden stretch during a vulnerable window, which is determined by repolarization inhomogeneity and activation of mechano-sensitive ion channels, reperfusion arrhythmias (commonly ventricular tachycardia and PVCs) during restoration of coronary perfusion in acute myocardial infarction.
Conclusion: further evaluation of whether few second only of post shock pause and rhythm analysis might reduce the risk for such refibrillation and hence outweigh the minimal interruption of CCs is warranted.