Thyroid Dysfunction in Torsades de Pointes To the Editor The Challenges in Clinical Electrocardiography article by Chew et al1 published in a recent issue of JAMA Internal Medicine describes the occurrence of recurrent syncope secondary to torsades de pointes (TdP) in a middle-aged woman.1 Alcohol and dextromethorphan use coupled with electrolyte abnormalities contributed to life-threatening polymorphic ventricular tachycardia treated with intravenous magnesium, amiodarone, and a temporary pacemaker. Although the clinical presentation, risk factors, and management aspects are well described, the patient’s thyroid function is not mentioned. Hypothyroidism has been reported as a rare but treatable cause of electrocardiographic QT prolongation and TdP.2,3 Severe or prolonged hypothyroidism, especially when accompanied by structural cardiac changes, cardiomyopathy, and congestive heart failure,4 can lead to bradycardia and first-degree block, and in some situations, precipitate ventricular dysrhythmias. Appropriate management has been reported to abolish the latter and may obviate the need for an implantable cardioverter-defibrillator.5 It is conceivable that in many of these cases a multitude of causative factors are involved, as in the patient described by Chew et al.1 However, satisfactory improvement may not occur if the hypothyroid state is overlooked and left untreated. In addition, the patient received the antiarrythmic drug amiodarone, which is high in iodine content and can induce thyroid dysfunction. Thus, an additional important reason to have knowledge of the thyroid status would be prior to the consideration of amiodarone administration. It is recommended that thyroid function be assessed early in the presentation of ventricular tachyarrythmias and TdP so that proper therapy can be instituted.

中文翻译：

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尖端扭转型甲状腺功能障碍

Thyroid Dysfunction in Torsades de Pointes 致编辑 Chew 等人在最近一期 JAMA Internal Medicine 上发表的《临床心电图挑战》文章描述了一名中年女性继发于尖端扭转型室速 (TdP) 的复发性晕厥的发生。 1酒精和右美沙芬的使用加上电解质异常导致了危及生命的多形性室性心动过速，静脉注射镁、胺碘酮和临时起搏器。尽管对临床表现、危险因素和管理方面进行了很好的描述，但并未提及患者的甲状腺功能。据报道，甲状腺功能减退症是心电图 QT 间期延长和 TdP 的一种罕见但可治疗的原因。2,3 严重或长期甲状腺功能减退症，尤其是伴有结构性心脏变化时，心肌病和充血性心力衰竭 4 可导致心动过缓和一级传导阻滞，在某些情况下会导致室性心律失常。据报道，适当的管理可以消除后者，并可能消除对植入式心律转复除颤器的需求。 5 可以想象，在许多这些情况下，涉及多种致病因素，如 Chew 等人所描述的患者 1。然而，如果甲状腺功能减退状态被忽视和不治疗，可能不会出现令人满意的改善。此外，患者接受了抗心律失常药物胺碘酮，该药物碘含量高，可诱发甲状腺功能障碍。因此，了解甲状腺状态的另一个重要原因是在考虑使用胺碘酮之前。