Woo Seok Lee1, Gi-Byoung Nam1, Sung-Hwan Kim2, Jin Hee Choi1, Uk Jo1, Won Young Kim3, Yong-Seog Oh2, Kyu Nam Park4, Guang-Won Seo5, Ki-Hun Kim5, Eun-Sun Jin6, Kyoung-Suk Rhee7, Laeyoung Jung7, Ki-Won Hwang8, Yoo Ri Kim9, Chang Hee Kwon10, Jun Kim1, Kee-Joon Choi1, You-Ho Kim1. 1. Department of Internal Medicine, Heart Institute, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea. 2. Division of Cardiology, Department of Internal Medicine, College of Medicine, Seoul St Mary's Hospital, The Catholic University of Korea, Seoul, Korea. 3. Department of Emergency Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea. 4. Department of Emergency Medicine, College of Medicine, Seoul St Mary's Hospital, The Catholic University of Korea, Seoul, Korea. 5. Department of Internal Medicine, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea. 6. Department of Internal Medicine, Kyung Hee University Hospital at Gangdong, College of Medicine, Kyung Hee University, Seoul, Korea. 7. Division of Cardiology, Chonbuk National University Hospital, Chonbuk National University, Jeonju, Korea. 8. Division of Cardiology, Department of Internal Medicine, Pusan National University Yangsan Hospital, Busan, Korea. 9. Division of Cardiology, Department of Internal Medicine, College of Medicine, Incheon St Mary's Hospital, The Catholic University of Korea, Seoul, Korea. 10. Division of Cardiology, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Korea.
Abstract
OBJECTIVE: Hypothermia can induce ECG J waves. Recent studies suggest that J waves may be associated with ventricular fibrillation (VF) in patients with structurally normal hearts. However, little is known about the ECG features, clinical significance or arrhythmogenic potentials of therapeutic hypothermia (TH)-induced J waves. METHODS: We analysed ECGs from 240 patients who underwent TH at six major university hospitals in Korea between August 2010 and December 2013. The prevalence, amplitudes and distributions of the J waves and the development of malignant arrhythmia were analysed. RESULTS: The average patient body temperature was 33.5±1.0°C during TH. J waves were observed in 98 patients (40.8%). They were newly developed in 91 cases, and pre-existing J waves were augmented in seven patients. J waves during TH were primarily observed in leads II, III, aVF and V4-6. The average amplitude of the J waves was 0.239±0.152 mV. There were four VF events during TH. These events occurred in three patients who were finally diagnosed with Brugada syndrome, idiopathic VF or early repolarisation syndrome, respectively, and in one patient with non-cardiac aetiology (asphyxia). CONCLUSIONS: J waves were recorded in about 40% of the patients who received TH. They were most frequently observed in the inferior limb leads or lateral precordial leads. Life-threatening VF occurred only rarely (1.7%) during TH and were mainly observed in patients with primary arrhythmic disorder. Although a causal relationship between TH-induced J waves and VF remains unknown, administering TH to this potentially susceptible, high-risk population may require careful attention. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
OBJECTIVE:Hypothermia can induce ECG J waves. Recent studies suggest that J waves may be associated with ventricular fibrillation (VF) in patients with structurally normal hearts. However, little is known about the ECG features, clinical significance or arrhythmogenic potentials of therapeutic hypothermia (TH)-induced J waves. METHODS: We analysed ECGs from 240 patients who underwent TH at six major university hospitals in Korea between August 2010 and December 2013. The prevalence, amplitudes and distributions of the J waves and the development of malignant arrhythmia were analysed. RESULTS: The average patient body temperature was 33.5±1.0°C during TH. J waves were observed in 98 patients (40.8%). They were newly developed in 91 cases, and pre-existing J waves were augmented in seven patients. J waves during TH were primarily observed in leads II, III, aVF and V4-6. The average amplitude of the J waves was 0.239±0.152 mV. There were four VF events during TH. These events occurred in three patients who were finally diagnosed with Brugada syndrome, idiopathic VF or early repolarisation syndrome, respectively, and in one patient with non-cardiac aetiology (asphyxia). CONCLUSIONS: J waves were recorded in about 40% of the patients who received TH. They were most frequently observed in the inferior limb leads or lateral precordial leads. Life-threatening VF occurred only rarely (1.7%) during TH and were mainly observed in patients with primary arrhythmic disorder. Although a causal relationship between TH-induced J waves and VF remains unknown, administering TH to this potentially susceptible, high-risk population may require careful attention. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Authors: Seung Mok Ryoo; Dong Hun Lee; Byung Kook Lee; Chun Song Youn; Youn-Jung Kim; Su Jin Kim; Yong Hwan Kim; Won Young Kim Journal: J Clin Med Date: 2019-09-01 Impact factor: 4.241
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