钙离子通道基因异常与室性心律失常

钙离子在维持心脏正常节律和兴奋-收缩耦联中发挥关键作用,钙离子通道相关蛋白的基因突变,可导致严重的心律失常。儿茶酚胺性多形性室性心动过速(CPVT)有常染色体显性遗传和隐性遗传两种形式,分别与肌浆网钙离子释放通道基因(RyR2)、贮钙蛋白基因(CASQ2)的突变有关;另一种新命名的“Timothy综合征”与细胞膜L型钙离子通道基因(CaV1.2)突变相关。     

儿茶酚胺敏感性多形性室速与心肌复极异常

儿茶酚胺敏感性多形性室速(catecholaminergic polymorphic ventricular tachycardia,CPVT)是一种恶性化程度较高的家族遗传性心律失常性疾病,临床上主要表现为由运动或情绪激动诱发(肾上腺素介导)的双向性和/或多形性室速、晕厥和猝死。CPVT的致病基因主要为RyR2和CASQ2。RyR2通道功能障碍造成的钙释放异常是引发CPVT的主要病理基础。本文对CPVT患者发生心肌复极异常的机制进行了综述。研究表明,肾上腺素刺激可加剧CPVT患者心肌细胞钙瞬变的不规则性与交替性变化,引起心肌复极不规则、QT间期变异程度加深,从而导致恶性心律失常。     

儿茶酚胺敏感性室性心动过速诊治新进展

临床研究表明儿茶酚胺敏感性室性心动过速（catecholaminergic polymorphic ventricular tachycardia,CPVT）是一种少见却严重的遗传性心律失常,表现为无器质性心脏病的个体在运动或激动时发生双向性、多形性室性心动过速（室速）导致发作性晕厥;当这些心律失常自行停止时,可自发性恢复;另一些情况下,室速转为心室颤动（室颤）,若未及时心肺复苏可导致猝死。     

其它遗传性心律失常的诊断及治疗

<正>1儿茶酚胺敏感性多形性室速儿茶酚胺敏感性多形性室速(CPVT)是一种高度恶性遗传性心律失常疾病,以运动或情绪激动(肾上腺素)诱发的双向性或多形性室速或猝死为特征,发生于无器质性心脏病,QT间期正常的青少年。1.1儿茶酚胺敏感性多形性室速临床表现儿茶酚胺敏感性多形性室速(CPVT)是Coumel等在1978年首次描述的以体力活动或情绪激动诱发的多形性室性心律失常和晕厥、静息心电图和心脏结构正常为特征的     

儿茶酚胺敏感多形性室性心动过速的临床与基因学研究进展

儿茶酚胺敏感多形性室性心动过速(catecholaminergic polymorphic ventricular tachycardia,CPVT)又称儿茶酚胺依赖型多形性或家族性多形性室性心动过速(VT),多发生于心脏结构及QT间期正常的儿童和年轻人,以运动或情绪激动时出现双向或多形性VT、导致晕厥和猝死为特征.CPVT为一种遗传性疾病,依据致病基因不同分为两种类型:(1)CPVT1:常染色体显性遗传,编码利罗丁受体2(ryanodine receptor 2,RyB2)基因突变所致;(2)CPVT2:常染色体隐性遗传,编码肌集钙蛋白2(calsequestrin2,CASQ2)基因突变所致.     

儿茶酚胺敏感性室性心动过速的植入式心律转复除颤器治疗

正儿茶酚胺敏感性多形性室性心动过速(catecholaminergic polymorphic ventricular tachy-cardia,CPVT)是一种高度恶性的遗传性心律失常疾病,以运动或情绪激动诱发的双向型和(或)多形性室性心动过速为特征,多发生于无器质性心脏病、QT间期正常的青少年。目前研究认为CPVT可分为常染色体显性遗传和隐性遗传两种形式,分别与编码心肌细胞肌浆网钙通道的RyR2基因和肌浆网内     

儿茶酚胺敏感性室性心动过速2例报告

儿茶酚胺敏感性室性心动过速(室速)又称儿茶酚胺敏感性多形性室速(CPVT),是一种家族遗传性离子通道病,也是导致年轻人心脏性晕厥及猝死的常见疾病之一。由于CPVT发病多为青少年,     

儿茶酚胺敏感性多形性室性心动过速的诊断

<正>儿茶酚胺敏感性室性心动过速(Catecholaminergic polymorphic ventricular tachycardia,CPVT)是一种少见的遗传性恶性心律失常。以运动或情绪激动诱发的双向性或多形性室速为特征,不伴结构性心脏病和QT间期延长[1],严重者可进一步发展为室颤而引起晕厥甚至猝死,是青少年发生心源性猝死的重要病因之一[2]。目前已经确定与CPVT有关的突变基因有RyR2~([3])和CASQ2~([4]),RyR2和CASQ2基因的突变使RyR2通道蛋白出现异常,引起心肌细胞肌质网持续     

儿茶酚胺敏感性室性心动过速心电图分析

儿茶酚胺敏感性室性心动过速又称儿茶酚胺敏感性多形性室性心动过速（catecholaminergic polymorphic ventricular tachycardia, CPVT）,是一种家族遗传性离子通道病,也是导致年轻人心脏性晕厥及猝死的常见疾病之一。     

心脏去交感神经术在恶性室性心律失常中的应用

恶性室性心律失常包括器质性和遗传性2大类,因可导致猝死严重危害人类健康。这些心律失常发生多与心脏交感神经激活有关。心脏交感神经切除术（CSD）通过切除下半部分星状神经节和前四对胸交感神经节可降低心脏交感神经活性,是恶性室性心律失常有效、安全的治疗手段。对于长QT综合征和儿茶酚胺敏感性多形性室性心动过速（CPVT）,单纯左侧CSD可能就已足够;对于器质性心脏病合并室性心律失常,双侧CSD可能具有更好疗效。     

A novel mutation in FKBP12.6 binding region of the human cardiac ryanodine receptor gene (R2401H) in a Japanese patient with catecholaminergic polymorphic ventricular tachycardia

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an autosomal dominant inherited disorder characterized by adrenergic induced polymorphic ventricular tachycardias and associated with sudden cardiac death. The human cardiac ryanodine receptor gene (RyR2) was linked to CPVT. A 20-year-old male was referred to our hospital because of recurrent syncope after physical and emotional stress. Routine cardiac examinations including catheterization revealed no structural abnormality. Exercise on treadmill induced premature ventricular contraction in bigeminy and bidirectional ventricular tachycardia was induced during isoproterenol infusion. Beta-blocking drug was effective in suppressing the arrhythmias. We performed genetic screening by PCR-SSCP method followed by DNA sequencing, and a novel missense mutation R2401H in RyR2 located in FKBP12.6 binding region was identified. This mutation was not detected in 190 healthy controls. Since FKBP12.6 plays a critical role in Ca channel gating, the R2401H mutation can be expected to alter Ca-induced Ca release and E-C coupling resulting in CPVT. This is the first report of RyR2 mutation in CPVT patient from Asia including Japan.     

Molecular and electrophysiological bases of catecholaminergic polymorphic ventricular tachycardia

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmogenic disorder characterized by adrenergically mediated polymorphic ventricular tachyarrhythmias. Genetic investigations have identified two variants of the disease: an autosomal dominant form associated with mutations in the gene encoding the cardiac ryanodine receptor (RyR2) and a recessive form associated with homozygous mutations in the gene encoding the cardiac isoform of calsequestrin (CASQ2). Functional characterization of mutations identified in the RyR2 and CASQ2 genes has demonstrated that CPVT are caused by derangements of the control of intracellular calcium. Investigations in a knock-in mouse model have shown that CPVT arrhythmias are initiated by delayed afterdepolarizations and triggered activity. In the present article, we review clinical and molecular understanding of CPVT and discuss the most recent approaches to develop novel therapeutic strategies for the disease.     

Sudden death in a young man with catecholaminergic polymorphic ventricular tachycardia and paroxysmal atrial fibrillation

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a familial condition that presents with exercise-induced syncope or sudden death in children or young adults. In most cases the disease is caused by a mutation in the cardiac ryanodine receptor (RyR2) gene. Current evidence suggests that primary therapy for CPVT is beta blockade and implantable cardioverter defibrillator (ICD) placement. There is a recent report of a patient with CPVT who died despite appropriate ICD therapies, and we report a similar case. Our patient died after probably initially receiving inappropriate ICD shocks for atrial fibrillation. We recommend that utmost efforts should be made to prevent shocks including repeated exercise testing to confirm suppression of PVT.     

Catecholaminergic Polymorphic Ventricular Tachycardia from Bedside to Bench and Beyond

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a primary electrical myocardial disease characterized by exercise- and stress-related ventricular tachycardia manifested as syncope and sudden death. The disease has a heterogeneous genetic basis, with mutations in the cardiac Ryanodine Receptor channel (RyR2) gene accounting for an autosomal-dominant form (CPVT1) in approximately 50% and mutations in the cardiac calsequestrin gene (CASQ2) accounting for an autosomal-recessive form (CPVT2) in up to 2% of CPVT cases. Both RyR2 and calsequestrin are important participants in the cardiac cellular calcium homeostasis.We review the physiology of the cardiac calcium homeostasis, including the cardiac excitation contraction coupling and myocyte calcium cycling. The pathophysiology of cardiac arrhythmias related to myocyte calcium handling and the effects of different modulators are discussed.The putative derangements in myocyte calcium homeostasis responsible for CPVT, as well as the clinical manifestations and therapeutic options available, are described.     

儿茶酚胺敏感性多形性室性心动过速患者的平板运动试验特点分析

目的研究儿茶酚胺敏感性多形性室性心动过速(CPVT)患者的平板运动试验特点。方法回顾性分析2006年9月至2014年3月在北京大学人民医院心内科临床诊断为CPVT的15例患者(其中男性9例,60.0%)的平板运动心电图资料。结果 (1)服用药物前,15例患者行平板运动试验均诱发出室性心律失常,阈值心率为(122.3±26.1)次/min,其中9例(60.0%)记录到特征性双向性室性心动过速,6例(40.0%)记录到双向性室性心动过速和多形性室性心动过速;(2)同时,8例患者(53.3%)记录到运动后的房性心律失常,且房性期前收缩阈值心率明显低于室性期前收缩[(91.5±26.3)次/min比(115.2±18.5)次/min,P=0.003];(3)15例患者在良好的监测下,平板运动试验安全性可靠。结论平板运动试验可安全有效诱发室性心律失常,对于CPVT的诊断有重要价值。     

Human cardiac ryanodine receptor mutations in ion channel disorders in Japan

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is characterized by adrenergic induced bidirectional or polymorphic ventricular tachycardias. Some of CPVT families were reported to be associated with cardiac ryanodine receptor gene (RyR2) mutations. However, association between RyR2 and other arrhythmogenic disorders is not clarified. In this study, we analyzed 83 Japanese patients including patients with long-QT syndrome, Brugada syndrome, idiopathic ventricular fibrillation, arrhythmogenic right ventricular cardiomyopathy and CPVT. Genetic screening of RyR2 revealed 3 distinct mutations among 4 families with CPVT (75% of incidence). However, no mutation was found in other groups. This is the first report to demonstrate prevalence of RyR2 mutations in various arrhythmogenic disorders in Japan. RyR2 mutations were detected frequently in CPVT but not in other diseases.     

New Family With Catecholaminergic Polymorphic Ventricular Tachycardia Linked to the Triadin Gene

We describe a new family with cathecholaminergic polymorphic ventricular tachycardia (CPVT) linked to the Triadin gene. This is the second report of such a CPVT of autosomal recessive inheritance. Using an NGS panel including 42 genes involved in cardiac sudden death, 2 heterozygous pathogenic mutations (c.613C> T/p.Gln205* and c.22 + 29 A>G) were identified in the Triadin gene in 2 sibs who experienced early severe arrhythmias without evidence of CPVT diagnosis at first cardiac evaluation. However, significant arrhythmias occurred after catecholaminergic stimulation. Each of the TRDN mutations was inherited from a healthy parent. In this family, genetic studies permit confirmation of the CPVT diagnosis in the 2 affected sibs and permit the early diagnosis of the third asymptomatic child. It also helped guide the therapeutic strategy in this family.     

Catecholaminergic Polymorphic Ventricular Tachycardia

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a highly lethal form of inherited arrhythmogenic disease characterized by adrenergically mediated polymorphic ventricular tachycardia. The mutations in cardiac ryanodine receptor and calsequestrin genes are responsible for the autosomal dominant and recessive variants of CPVT, respectively. The clinical presentation encompasses exercise- or emotion-induced syncopal events and a distinctive pattern of reproducible, stress-related, bidirectional ventricular tachycardia in the absence of both structural heart disease and a prolonged QT interval. The mortality rate in untreated individuals is 30-50% by age 40. Clinical evaluation by exercise stress testing and holter monitoring and genetic screening can facilitate early diagnosis. beta-adrenergic blockers are the most effective pharmacological treatment in controlling arrhythmias in CPVT patients, yet about 30% of patients still experience cardiac arrhythmias and eventually require an implantable cardioverter defibrillator.     

Guidelines for the diagnosis and management of Catecholaminergic Polymorphic Ventricular Tachycardia

BACKGROUND: Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) is an inherited arrhythmia syndrome, characterised by polymorphic ventricular tachycardia induced by adrenergic stress. CPVT can be caused by mutations the cardiac ryanodine receptor gene (RYR2) or mutations in the cardiac calsequestrin gene CASQ2. Structural heart disease is usually absent and the baseline ECG is usually normal. Patients with CPVT often present with exercise- or emotion induced syncope, the first presentation can also be sudden cardiac death. MANAGEMENT: Besides removal of triggers treatment with beta blockers is currently a class I indication in clinically diagnosed patients. Beta blockage should be titrated up to an effective level. The addition of flecainide seems to be a promising approach in patients where arrhythmias are not completely suppressed by beta blockers. A cardioverter-defibrillator (ICD) or left cervical sympathetic denervation might be considered under special circumstances. Genetic counselling is recommended and all first degree relatives should be properly evaluated.     

Bidirectional ventricular tachycardia and fibrillation elicited in a knock-in mouse model carrier of a mutation in the cardiac ryanodine receptor

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited disease characterized by adrenergically mediated polymorphic ventricular tachycardia leading to syncope and sudden cardiac death. The autosomal dominant form of CPVT is caused by mutations in the RyR2 gene encoding the cardiac isoform of the ryanodine receptor. In vitro functional characterization of mutant RyR2 channels showed altered behavior on adrenergic stimulation and caffeine administration with enhanced calcium release from the sarcoplasmic reticulum. As of today no experimental evidence is available to demonstrate that RyR2 mutations can reproduce the arrhythmias observed in CPVT patients. We developed a conditional knock-in mouse model carrier of the R4496C mutation, the mouse equivalent to the R4497C mutations identified in CPVT families, to evaluate if the animals would develop a CPVT phenotype and if beta blockers would prevent arrhythmias. Twenty-six mice (12 wild-type (WT) and 14RyR(R4496C)) underwent exercise stress testing followed by epinephrine administration: none of the WT developed ventricular tachycardia (VT) versus 5/14 RyR(R4496C) mice (P=0.02). Twenty-one mice (8 WT, 8 RyR(R4496C), and 5 RyR(R4496C) pretreated with beta-blockers) received epinephrine and caffeine: 4/8 (50%) RyR(R4496C) mice but none of the WT developed VT (P=0.02); 4/5 RyR(R4496C) mice pretreated with propranolol developed VT (P=0.56 nonsignificant versus RyR(R4496C) mice). These data provide the first experimental demonstration that the R4496C RyR2 mutation predisposes the murine heart to VT and VF in response caffeine and/or adrenergic stimulation. Furthermore, the results show that analogous to what is observed in patients, beta adrenergic stimulation seems ineffective in preventing life-threatening arrhythmias.