Letter by Pettit et al Regarding Article, “Electrical Heart Activity Recorded During Prolonged Avalanche Burial”
To the Editor:
We were interested to read the tragic case report in which an individual died after avalanche burial with an active heart rate recording device.1 Individuals have been resuscitated from core temperatures as low as 19°C after avalanche burial.2 Rescuers are advised to exercise care when handling casualties because of the risk of triggering ventricular arrhythmias, although the true incidence of arrhythmias in this setting is unknown.3 This case offers a unique insight into rhythm disturbances after avalanche burial. Unfortunately, we have concerns about the presented data. The authors report 5 distinct phases of arrhythmia, 3 of which are represented by a completely flat line on the graph of heart rate versus time, implying prolonged arrhythmias with absolutely constant cycle length. It is unlikely that such stable arrhythmias would be punctuated by periods of marked heart rate instability. An alternative and more plausible explanation is that these flat lines represent artifact, a very common cause of flat lines on heart rhythm recordings. Potential sources are interference from communication or transceiver equipment used by rescuers, or chest strap movement relative to the victim's skin. We do not think it can be safely concluded that spontaneous electric cardiac activity was present until the moment of extrication, nor that cardiac arrest was triggered by extrication. This is important because international guidelines on avalanche rescue are based on low-grade evidence such as case reports and case series.3 However, we agree with the authors that avalanche victims extricated in cardiac arrest with an unobstructed airway should be treated optimistically, with full resuscitation including extracorporeal rewarming.
Stephen J. Pettit, MBBS, PhD
Scottish National Advanced Heart Failure Service
Golden Jubilee National Hospital
Clydebank, Glasgow, UK
Parminder S. Chaggar, MBChB
Department of Cardiology
Southend University Hospital
Jeremy S. Windsor, MBChB
Institute of Human Health and Performance
University College London
- © 2012 American Heart Association, Inc.