Thomsen JH, Hassager C, Erlinge D, Nielsen N, Lindholm MG, Bro-Jeppesen J, Grand J, Pehrson S, Graff C, Køber LV, Kjaergaard J. Repolarization and ventricular arrhythmia during targeted temperature management post cardiac arrest.
Resuscitation 2021;
166:74-82. [PMID:
34271131 DOI:
10.1016/j.resuscitation.2021.07.004]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 06/28/2021] [Accepted: 07/03/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND
Targeted temperature management (TTM) following out-of-hospital cardiac arrest (OHCA) prolongs the QT-interval but our knowledge of different temperatures and risk of arrhythmia is incomplete.
OBJECTIVE
To assess whether the QTc, QT-peak (QTp) and T-peak to T-end interval (TpTe) may be useful markers of ventricular arrhythmia in contemporary post cardiac arrest treatment.
METHODS
An ECG-substudy of the TTM-trial (TTM at 33 °C vs. 36 °C) with serial ECGs from 680 (94%) patients. Bazett's (B) and Fridericia's (F) formula were used for heart rate correction of the QT, QTp and TpTe. Ventricular arrhythmia (VT/VF) were registered during the first three days of post cardiac arrest care.
RESULTS
The QT, QTc and QTp intervals were prolonged more at 33 °C compared to 36 °C and restored to similar and lower levels after rewarming. The TpTe-interval remained between 92-100 ms throughout TTM in both groups. The QTc intervals were associated with ventricular arrhythmia, but not after adjustment for cardiac arrest characteristics. The QTp-interval was not associated with risk of ventricular arrhythmia. Heart rate corrected TpTe-intervals were associated with higher risk of arrhythmia (Odds ratio (OR): TpTe(B): 1.12 (1.02-1.23, p = 0.01 TpTe(F): 1.12 (1.02-1.23, p = 0.02) per 20 ms). Further a prolonged TpTe-interval ≥ 90 ms was consistently associated with higher risk (ORadjusted: TpTe(B): 2.05 (1.25-3.37), p < 0.01, TpTe(F): 2.14 (1.32-3.49), p < 0.01).
CONCLUSIONS
TTM prolongs the QT-interval by prolongation of the QTp-interval without association to increased risk. The TpTe-interval is not significantly affected by core temperature, but heart rate corrected TpTe intervals are robustly associated with risk of ventricular arrhythmia.
TRIAL REGISTRATION
The TTM-trial is registered and accessible at ClinicalTrials.gov (Identifier: NCT01020916).
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