Department of Cardiovascular Medicine, Shiga University of Medical Science, Otsu, Japan.
Department of Bioscience and Genetics, National Cerebral and Cardiovascular Center, Suita, Japan.
BMC Cardiovasc Disord. 2020 Jul 2;20(1):315. doi: 10.1186/s12872-020-01601-2.
Loss-of-function mutations of human cardiac sodium channel gene SCN5A induce a wide range of arrhythmic disorders. Mutation carriers with co-existing conditions such as congenital heart diseases and histories of cardiac surgeries, could develop complex arrhythmic events that are difficult to diagnose.
A 41-year-old Japanese male with a history of a surgical closure of an ASD presented impairment of consciousness by wide QRS tachycardia. Because the patient's baseline ECG in sinus rhythm showed similar QRS axis with right bundle brunch block morphology, we suspected supraventricular tachycardia (SVT). During hospitalization, the patient developed polymorphic ventricular tachycardia that was induced by bradycardia. In an electrophysiological study, the SVT was identified as right atrial incisional tachycardia circulating around the scar in the right atrium. The genetic analysis revealed a heterozygous SCN5A c.4037-4038 del TC, p. L1346HfsX38 variant. We diagnosed this patient as having progressive cardiac conduction disorder (PCCD) and polymorphic VT caused by the mutation. Incisional tachycardia with wide QRS morphology was a by-standing comorbidity related to the history of cardiac surgery which could miss lead the diagnosis. The patient's SVT was eliminated by radiofrequency catheter ablation. An implantable cardioverter defibrillator (ICD) was implanted for the secondary prevention of polymorphic VT. Cardiac pace-making therapy by the ICD to avoid bradycardia effectively suppressed the patient's arrhythmic events.
We treated a patient with a sodium channel gene variant. Co-existing SVT originated by a scar in the right atrium made the diagnosis extremely difficult. A multilateral diagnostic approach using an ECG analysis, an electrophysiological study, and genetic screening enabled effective combination therapy comprised of catheter ablation and an ICD.
人类钠离子通道基因 SCN5A 的失活突变可引起广泛的心律失常疾病。携带有共存病症（如先天性心脏病和心脏手术史）的突变携带者可能会发生难以诊断的复杂心律失常事件。
一名 41 岁的日本男性，曾接受过房间隔缺损的手术封堵，因宽 QRS 心动过速导致意识障碍而就诊。由于患者窦性心律时的基础心电图显示与右束支传导阻滞形态相似的类似 QRS 轴，我们怀疑为室上性心动过速（SVT）。住院期间，患者发生了由心动过缓诱发的多形性室性心动过速。在电生理研究中，SVT 被确定为围绕右心房瘢痕的右心房切口性心动过速。基因分析显示杂合 SCN5A c.4037-4038 del TC，p. L1346HfsX38 变异。我们诊断该患者患有进行性心脏传导障碍（PCCD）和由突变引起的多形性 VT。宽 QRS 形态的切口性心动过速是与心脏手术史相关的并存疾病，可能导致诊断遗漏。该患者的 SVT 通过射频导管消融消除。为预防多形性 VT，植入了植入式心脏复律除颤器（ICD）。通过 ICD 进行心脏起搏治疗以避免心动过缓，有效地抑制了患者的心律失常事件。
我们治疗了一名携带钠离子通道基因突变的患者。起源于右心房瘢痕的共存性 SVT 使得诊断极其困难。使用心电图分析、电生理研究和基因筛查的多方位诊断方法，使我们能够有效地进行导管消融和 ICD 联合治疗。
