Jatti Kumar, Prasad Neeraj
Hereford County Hospital, Hereford, UK.
SAGE Open Med Case Rep. 2015 Jun 3;3:2050313X15581267. doi: 10.1177/2050313X15581267. eCollection 2015.
Therapeutic hypothermia has been used for neuroprotection following cardiac arrest presenting with ventricular tachycardia or ventricular fibrillation regardless of underlying cause. Long QT syndrome is a cause for polymorphic ventricular tachycardia, and we know that therapeutic hypothermia increases the QT interval. We managed a 27-year-old woman, who was 10 weeks post-partum, who collapsed secondary to ventricular fibrillation at home. Bystander cardiopulmonary resuscitation was started with successful resuscitation after a rescue shock from paramedics. On hospital admission, her computerised tomography head, computerised tomography pulmonary angiogram and echocardiography did not show any abnormality. Her baseline electrocardiogram showed prolonged QTc interval of 504 ms without ischaemic changes. After intubation and ventilation, she was treated with therapeutic hypothermia for 48 h. She had a further episode of polymorphic ventricular tachycardia requiring rescue shock just prior to starting therapeutic hypothermia in hospital. No dysrhythmias occurred during therapeutic hypothermia, although the QTc further increased. After stopping the therapeutic hypothermia, she had two further ventricular tachycardia episodes. After commencement of beta blockers, she remained free of arrhythmias, and an implantable cardioverter defibrillator was implanted, she has recovered without any neurological deficit. Ventricular dysrhythmias caused by prolongation of the QT interval during or after therapeutic hypothermia are not well understood. There has been a report of a patient also having ventricular dysrhythmia 2 h after re-warming post therapeutic hypothermia and also a report of arrhythmia free period during therapeutic hypothermia in a long QT syndrome patient; both these features are present in our patient. Re-warming is not usually known to cause any arrhythmias; however, it could be a problem in those with long QT syndrome. Whether therapeutic hypothermia has a place in helping to control ventricular dysrhythmias needs further study.
治疗性低温已被用于心脏骤停伴室性心动过速或室颤后的神经保护，无论其潜在病因如何。长QT综合征是多形性室性心动过速的一个病因，并且我们知道治疗性低温会延长QT间期。我们治疗了一名27岁的产后10周女性，她在家中因室颤而晕倒。旁观者开始进行心肺复苏，医护人员电击除颤后成功复苏。入院时，她的头颅计算机断层扫描、计算机断层扫描肺动脉造影和超声心动图均未显示任何异常。她的基线心电图显示QTc间期延长至504毫秒，无缺血性改变。插管和通气后，她接受了48小时的治疗性低温治疗。在医院开始治疗性低温之前，她又发生了一次多形性室性心动过速，需要电击除颤。治疗性低温期间未发生心律失常，尽管QTc进一步延长。停止治疗性低温后，她又发生了两次室性心动过速发作。开始使用β受体阻滞剂后，她未再发生心律失常，并植入了植入式心脏复律除颤器，她已康复且无任何神经功能缺损。治疗性低温期间或之后因QT间期延长导致的室性心律失常尚未完全明确。有报道称一名患者在治疗性低温复温后2小时也出现了室性心律失常，还有报道称一名长QT综合征患者在治疗性低温期间无心律失常期；我们的患者同时具备这两个特征。通常认为复温不会引起任何心律失常；然而，对于长QT综合征患者可能是个问题。治疗性低温在帮助控制室性心律失常方面是否有作用需要进一步研究。
