Edina Hadziselimovic1, Jakob Hartvig Thomsen2, Jesper Kjaergaard2, Lars Køber2, Claus Graff3, Steen Pehrson2, Niklas Nielsen4, David Erlinge5, Martin Frydland2, Sebastian Wiberg2, Christian Hassager2. 1. Department of Cardiology, The Heart Centre, Copenhagen University Hospital Rigshospitalet, Denmark. Electronic address: edina@edina.dk. 2. Department of Cardiology, The Heart Centre, Copenhagen University Hospital Rigshospitalet, Denmark. 3. Department of Health Science and Technology, Aalborg University, Denmark. 4. Department of Anesthesia and Intensive Care, Helsingborg Hospital, Helsingborg, Sweden. 5. Department of Cardiology, Lund University Hospital, Lund, Sweden.
Abstract
BACKGROUND: The Osborn or J-wave, an upright deflection of the J-point on the electrocardiogram (ECG), is often observed during severe hypothermia. A possible relation between Osborn waves (OW) and increased risk of ventricular arrhythmia has been reported. We sought to determine whether the level of targeted temperature management (TTM) following out-of-hospital cardiac arrest (OHCA) affects the prevalence of OW and to assess the associations between OW and risk of ventricular arrhythmia and death. METHODS AND RESULTS: The present study is part of the TTM-trial ECG-substudy (including OHCA-patients randomized to TTM at 33 °C vs. 36 °C from 24 of 36 sites). Serial 12-lead ECGs from 680 (94%) patients were analysed and stratified by OW at predefined time-points (0, 4, 28, 36, 72-h after admission). On admission, the overall prevalence of OW was 16%, increasing to 32% at target temperature, with higher prevalence in the 33 °C-group (40% vs. 23%, p < 0.0001). No difference in prevalence was found between the 33 °C- and 36 °C-groups on admission (18% vs. 14%, p = .11) or after rewarming (13% vs. 10%, p = .44). OW were not associated with increased risk of ventricular arrhythmia (Odds ratio = 0.78 (0.51-1.20), p = .26), but associated with significantly lower 180-day mortality as compared to no OW (38% vs. 52%, plog-rank = 0.001) in univariable analyses only. CONCLUSION: OW are frequent during TTM, particularly in patients treated with 33 °C. OW are not associated with increased risk of ventricular arrhythmia, and may be considered a benign physiological phenomenon, associated with lower mortality in univariable analyses.
RCT Entities:
BACKGROUND: The Osborn or J-wave, an upright deflection of the J-point on the electrocardiogram (ECG), is often observed during severe hypothermia. A possible relation between Osborn waves (OW) and increased risk of ventricular arrhythmia has been reported. We sought to determine whether the level of targeted temperature management (TTM) following out-of-hospital cardiac arrest (OHCA) affects the prevalence of OW and to assess the associations between OW and risk of ventricular arrhythmia and death. METHODS AND RESULTS: The present study is part of the TTM-trial ECG-substudy (including OHCA-patients randomized to TTM at 33 °C vs. 36 °C from 24 of 36 sites). Serial 12-lead ECGs from 680 (94%) patients were analysed and stratified by OW at predefined time-points (0, 4, 28, 36, 72-h after admission). On admission, the overall prevalence of OW was 16%, increasing to 32% at target temperature, with higher prevalence in the 33 °C-group (40% vs. 23%, p < 0.0001). No difference in prevalence was found between the 33 °C- and 36 °C-groups on admission (18% vs. 14%, p = .11) or after rewarming (13% vs. 10%, p = .44). OW were not associated with increased risk of ventricular arrhythmia (Odds ratio = 0.78 (0.51-1.20), p = .26), but associated with significantly lower 180-day mortality as compared to no OW (38% vs. 52%, plog-rank = 0.001) in univariable analyses only. CONCLUSION: OW are frequent during TTM, particularly in patients treated with 33 °C. OW are not associated with increased risk of ventricular arrhythmia, and may be considered a benign physiological phenomenon, associated with lower mortality in univariable analyses.