Abstract 14922: Elevated Heart Rate Variability, Measured As Increased SDNN, During Therapeutic Hypothermia Can Predict Better Outcomes Among Post-resuscitation Rats
Introduction: Heart rate variability (HRV) has been documented to be of prognostic values in various diseases, notably chronic heart failure and cardiomyopathy after myocardial infarction. Some clinical studies have also shown the association between increased HRV and better post-resuscitation outcomes in out-of-hospital-cardiac-arrest patients. Nevertheless, limited data has demonstrated the relationship between HRV during therapeutic hypothermia (TH) and post-resuscitation outcomes.
Hypothesis: The HRV during TH is predictive of post-resuscitation outcomes among rats subjected to experimental cardiac arrest (CA).
Methods: Adult male Wistar rats were subjected to asphyxial CA and then underwent CPR. After return of spontaneous circulation (ROSC), TH was immediately implemented using external cooling method, targeting an intravascular temperature of 32 to 32.5 °C. The body temperature and ECG signals were recorded continuously throughout the experiment. Three-day survival was assessed, and HRV during TH was calculated using the recorded ECG signals.
Results: A total of 9 rats were resuscitated and underwent TH. Seven of them survived for 3 days and were categorized as the survival group. The heart rate (HR) between the survival and non-survival groups was not different during TH (Figure 1). The HRV, as measured using SDNN, was significantly increased throughout the course of TH in the survival group (Figure 2).
Conclusions: An increased SDNN was observed during TH in post-resuscitation rats with favorable outcomes. This higher HRV was independent of HR, suggesting the potential use of SDNN as a prognosticator during TH.
- © 2010 by American Heart Association, Inc.