A 46-year-old man with no history of syncope presented with sudden cardiac arrest. Prior to arrival, he had received bystander cardiopulmonary resuscitation for 5 min and defibrillation with an automated external defibrillator. Spontaneous circulation had returned while at the scene. However, he was unconscious upon admission to the hospital, where an electrocardiogram (ECG) revealed J-wave elevation over a wide range of leads (I, II, III, aVR, aVF, and V3–6; Fig. 1a). His body temperature (36.8°C) and other vital signs were within the normal limits.
Figure 1.
a) Electrocardiogram recorded upon admission shows J waves in leads I, II, III, aVR, aVF, and V3–6. b) Electrocardiogram after induced hypothermia shows further elevation of J-waves with multifocal ventricular premature complexes.
Emergency coronary angiography findings showed no significant coronary artery stenosis. After we induced therapeutic hypothermia (34°C) [1], ECG showed further elevation of J-waves with multifocal ventricular premature complexes (PVCs) (Fig. 1b). Furthermore, the patient experienced recurrent episodes of ventricular fibrillation (VF). Amiodarone, lidocaine, magnesium, and landiolol were ineffective at resolving the VF storm; however, isoproterenol was effective [2]. A Brugada-type electrocardiogram pattern was never observed. Thus, we diagnosed the patient with J-wave (early repolarisation) syndrome. The differential diagnosis of J-wave syndrome includes intraventricular conduction delay-induced end QRS notch syndrome as well as Brugada syndrome [3].
In our patient’s case, therapeutic hypothermia negatively impacted J-wave syndrome [4]. After performing catheter ablation for the PVCs that were triggering VF and implantation of a cardioverter defibrillator, the patient experienced no further incidences of VF [5].
ACKNOWLEDGEMENTS
We would like to thank Editage (www.editage.jp) for English language editing.
Contributor Information
Masahiro Kashiura, Department of Emergency and Critical Care Medicine, Saitama Medical Centre, Jichi Medical University, Saitama, 330-8503, Japan.
Yuichi Hamabe, Tertiary Emergency Medical Centre, Tokyo Metropolitan Bokutoh Hospital, Tokyo, 130-8575, Japan.
Takashi Moriya, Department of Emergency and Critical Care Medicine, Saitama Medical Centre, Jichi Medical University, Saitama, 330-8503, Japan.
FUNDING
None.
CONFLICT OF INTERTEST
No conflicts of interest.
ETHICAL APPROVAL
No approval was required.
CONSENT
Written informed consent was obtained from the patient for publication of this case report and any accompanying images.
GUARANTOR
Masahiro Kashiura is the guarantor of this article.
REFERENCES
- 1. Schenone AL, Cohen A, Patarroyo G, Harper L, Wang X, Shishehbor MH et al. Therapeutic hypothermia after cardiac arrest: a systematic review/meta-analysis exploring the impact of expanded criteria and targeted temperature. Resuscitation 2016;108:102–10. 10.1016/j.resuscitation.2016.07.238. [DOI] [PubMed] [Google Scholar]
- 2. Shiozaki M, Sumiyoshi M, Tabuchi H, Hayashi H, Tamura H, Inoue K et al. A case of J wave syndrome due to severe hypercalcemia with ventricular fibrillation storm and successful treatment of isoproterenol infusion. Int Heart J 2021;62:924–6. 10.1536/ihj.20-798. [DOI] [PubMed] [Google Scholar]
- 3. Antzelevitch C, Yan G, Ackerman MJ, Borggrefe M, Corrado D, Guo J et al. J-wave syndromes expert consensus conference report: emerging concepts and gaps in knowledge. J Arrhythmia 2018;32:315–39. 10.1016/j.joa.2016.07.002. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4. Hasegawa K, Miyazaki S, Morishita T, Kaseno K, Hisazaki K, Amaya N et al. A slower heart rate and therapeutic hypothermia unmasked early repolarization syndrome in a ventricular fibrillation survivor. Int Heart J 2019;60:185–8. 10.1536/ihj.18-024. [DOI] [PubMed] [Google Scholar]
- 5. Nademanee K, Haissaguerre M, Hocini M, Nogami A, Cheniti G, Duchateau J et al. Mapping and ablation of ventricular fibrillation associated with early repolarization syndrome. Circulation 2019;140:1477–90. 10.1161/circulationaha.118.039022. [DOI] [PubMed] [Google Scholar]