Electrocardiographic changes in patients undergoing targeted temperature management

Abstract

Objectives Targeted temperature management is the recommended therapy for comatose patients after an out‐of‐hospital cardiac arrest resuscitation due to the reduction in neurological damage and improved outcomes. However, there may result in electrocardiographic instability depending on the degree of targeted temperature management, including minor or life‐threatening dysrhythmias or conduction delays. This project aims to describe the frequency of ECG interval changes and clinically relevant dysrhythmias in targeted temperature management patients. Methods This is a retrospective observational study from January 2009 to December 2015. Patients who qualified for the study had a non‐traumatic cardiac arrest with a return of spontaneous circulation, received targeted temperature management at 33.5°C for 24 hours followed by 16 hours of rewarming. ECG interval changes and dysrhythmias were recorded immediately after return of spontaneous circulation, and at 24 and 48 hours post return of spontaneous circulation. Results A total of 322 patients (age 61.0 ± 16.9 years) had targeted temperature management initiated during the study period, of which 169 had complete data and 13 died prior to completing 24 hours of hypothermia. There were statistically significant changes during targeted temperature management in heart rate (96.7 ± 26.0/min before targeted temperature management; 69.5 ± 19.1/min during, P < 0.001), QRS duration (115.1 ± 32.6 ms before targeted temperature management; 107.8 ± 27.9 ms during targeted temperature management, P < 0.001), and QTc (486.3 ± 52.8 ms before targeted temperature management; 526.9 ± 61.7 ms during targeted temperature management, P < 0.001). There were cardiac dysrhythmias that received treatment during cooling and rewarming. Conclusion During the period of targeted temperature management and rewarming, we observed few self‐limiting ECG interval changes and no clinically significant dysrhythmias in this population during the period of targeted temperature management.

The Effect of Hypothermia and Osmotic Shock on the Electrocardiogram of Adult Zebrafish

“…Following serious health complications, such as a heart attack or stroke, which result in a drastically reduced blood supply to the brain, target temperature management is often employed to reduce the risk of neuronal damage [42]. However this treatment is also known to impact cardiac electrophysiology and can lead to the lengthening of the QT interval and the potential for lethal arrhythmias [14,42]. Similarly, using the exposed heart configuration, we also observed that subjecting zebrafish to hypothermia resulted in a significant increase in the QT interval.…”

Characterization of the adult zebrafish electrocardiogram

“…Following serious health complications, such as a heart attack or stroke, which result in a drastically reduced blood supply to the brain, target temperature management is often employed to reduce the risk of neuronal damage [39]. However this treatment is also known to impact cardiac electrophysiology and can lead to the lengthening of the QT interval and the potential for lethal arrhythmias [35,39]. Similarly, using the exposed heart configuration, we also observed that subjecting zebrafish to hypothermia resulted in a significant increase in the QT interval.…”

Effectiveness of Induced Hypothermia on the Prognosis of Post-cardiac Arrest Patients: A Scoping Literature Review

“…Such low temperatures are rarely used nowadays, but with methods like SCD without automated control for hypothermia induction when used, the chances of overshooting hypothermia are not uncommon. Sinus bradycardia is the most common conduction abnormality seen during the cooling phase with studies showing prolongation of PR-interval, QTc prolongation, and ventricular escape rhythms [ 33 ]. No special attention is usually needed as they resolve during the rewarming phase.…”