Abstract 19243: Late Repolarization During Targeted Temperature Management at 33 Degree C vs. 36 Degree C and Risk of Ventricular Arrhythmia in Post Cardiac Arrest Care
Background: The T-peak to T-end interval (TPTE) has emerged as a potential clinically useful marker of risk of ventricular arrhythmia. Both the effect of the level of targeted temperature management (TTM) following out-of-hospital cardiac arrest (OHCA) on the TPTE-interval and the importance of the interval in assessing risk of ventricular arrhythmia in post cardiac arrest care is unknown.
Methods: An ECG-substudy of the TTM-trial which compared TTM at 33C vs. 36C. From 24 sites, serial ECGs (0, 4, 28, 36 and 72 hours after admission) in 682 (94%) patients were analyzed. Bazett’s (TPTE(B)) and Fridericia’s (TPTE(F)) formula were used for heart rate correction. Occurrence of ventricular arrhythmia (VT and VF) was assessed during the first three days of post cardiac arrest care.
Results: The TPTE-interval remained relatively constant between 92-100 ms from admission and throughout the maintenance phase of TTM in both groups, but decreased after rewarming (Figure 1). A small difference (33C: 100 ms vs. 36C: 93 ms, p=0.04) was found at target temperature, but this was attenuated by both methods of heart rate correction. Ventricular arrhythmia occurred with similar incidences between temperature groups (33C: 61 (18%) vs. 36C: 49 (15%), p=0.30). The uncorrected TPTE-interval at target temperature, were not significantly associated with risk of ventricular arrhythmia (p=0.08), however longer heart rate corrected TPTE-intervals were associated with higher risk of arrhythmia (Odds ratio: 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), independent of method applied.
Conclusion: The TPTE-interval is not greatly affected by core temperature, and the small difference found was explained by different heart rates. Corrected TPTE intervals are directly associated with increased risk of ventricular arrhythmia and may represent a clinically useful marker of risk in post cardiac arrest patients treated with TTM at both 33C and 36C.
Author Disclosures: J.H. Thomsen: None. C. Hassager: None. C. Graff: None. S. Pehrson: None. L. Køber: None. D. Erlinge: None. J. Bro-Jeppesen: None. J. Kjaergaard: None.
- © 2016 by American Heart Association, Inc.