儿茶酚胺敏感性多形性室性心动过速的研究进展

儿茶酚胺敏感性多形性室性心动过速(CPVT)是一种原发性心脏电紊乱,可能是非器质性心脏病患者发生猝死的重要原因。少年及成人均可患病。异常的RyR2通道或CASQ2蛋白在交感兴奋的条件下诱发的延迟后除极可能是CPVT发生的机制。任何患者无论年龄大小,只要是交感神经系统兴奋诱发的双向或多形性室性心动过速,无器质性心脏病且QT间期正常,都应考虑CPVT的诊断。β受体阻滞剂可以控制大部分患者的心动过速发作。CPVT患者发生过心脏骤停为埋藏式心脏转复除颤器(ICD)治疗的Ⅰ类适应证。服用β受体阻滞剂时出现晕厥者为ICD治疗的Ⅱa类适应证。对于致病基因的携带者,特别是儿童,都应服用β受体阻滞剂进行一级预防。     

儿茶酚胺敏感性多形性室性心动过速二例

2例无器质性心脏病,反复运动或情绪激动诱发晕厥儿童,运动试验和电生理检查明确儿茶酚胺敏感性多形性室性心动过速诊断。伴有明显缓慢性心律失常包括窦性心动过缓、窦性停搏,分别置入AAI和VVI起搏器,并予以较大剂量β受体阻滞剂口服,随访半年到一年,日常生活正常,无晕厥发作。     

儿茶酚胺敏感性多形性室速的基因诊治进展

儿茶酚胺敏感性多形性室速(CPVT)是具有较高猝死风险的罕见单基因遗传病.已知多种CPVT基因突变可通过影响肌浆网钙通道蛋白RyR2的功能,破坏细胞内钙稳态,触发室性心律失常,而依靠腺相关病毒载体(AAVs)及CRISPR/Cas9技术进行基因层面的干预有望为CPVT的治疗提供新思路.本文就其遗传特征及基因干预等领域的研究现状作一总结.     

儿茶酚胺敏感性多行性室性心动过速的研究进展

儿茶酚胺敏感性多形性室性心动过速(CPVT)是一种由心肌钙离子失调引起的罕见遗传性离子通道病,其特征是由交感肾上腺系统兴奋诱发的多形性室性心动过速,患者可表现为晕厥甚至心源性猝死。约56%的CPVT患者存在RyR2或CASQ2基因突变,该突变可导致心肌细胞肌质网的钙泄露,继而引起延迟后除极和触发冲动,但仍有近一半的患者病因未明。儿童、青少年进行体育锻炼或情绪激动时突发晕厥,应高度怀疑CPVT。β受体阻滞剂可有效减少室性心动过速的发作,既往有心脏骤停病史的患者,可置入心脏转复除颤器。目前的治疗方法还有交感神经节切除术、射频消融术等,基因治疗有可能成为未来的治疗方向。     

中国儿茶酚胺敏感性多形性室性心动过速患者RyR2基因突变分析

目的拟研究中国儿茶酚胺敏感性多形性室性心动过速(CPVT)患者的兰尼丁受体(RyR2)基因变异情况。方法研究对象来自参与中国离子通道病全国注册的4个CPVT家系,收集其基本临床资料。提取先证者及其父母DNA样本,用PCR方法扩增RyR2基因突变集中的45个外显子及内含子-外显子拼接部位序列并直接测序。结果发现2个CPVT先证者分别携带杂合突变p.Arg169Gln和p.Leu2534Val。在其父母和100名正常对照者中未发现相同突变,提示这两个突变均为新发突变(de novo),并在多个物种中高度保守。结论结合已知突变报道推测p.Arg169Gln可能是引起亚洲人CPVT的热点突变位点。     

儿茶酚胺敏感性室性心动过速患者1例的护理

目的 报告1例儿茶酚胺敏感性多形性室性心动过速患者的护理,探讨其护理要点.方法 从心理护理、晕厥的观察及护理、安装植入式心脏复律除颤器护理、出院指导和随访等方面探讨护理要点.结果 经积极治疗和护理,患者未再发生晕厥,健康状况良好.结论 加强心理护理,做好家属情感的支持,加强在院期间的监测,做好晕厥的护理、重点落实植入式心脏复律除颤器植入术的护理,完善出院指导,加强出院后的长期随访工作,是该患者健康的有力保证.     

儿茶酚胺敏感性多形性室速1例

患者女性,51岁,主因间歇发作性晕厥8年,间断胸骨后不适5天,行平板运动试验中再次发生晕厥于2008年2月22日由门诊收入院。既往高血压病史10年,高脂血症5年。患者8年来间歇发作晕厥2次,均与运动和情绪激动有关,为寻找病因,医生建议行平板运动试验。运动试验采用美国GE公司生产     

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

苑医师(住院医师) 本次查房的患儿为女性,11岁,因发作性晕厥4年,植入AAI起搏器10天再次发生晕厥入院.     

兰尼碱受体2磷酸化异常在儿茶酚胺敏感性室性心动过速中的作用

兰尼碱受体2（RyR2）是调节心肌细胞兴奋收缩偶联的重要离子通道蛋白,RyR2的磷酸化在生理条件下调节心肌细胞肌浆网Ca 2+储存和释放过程。儿茶酚胺敏感性多形性室性心动过速（CPVT）是一种遗传性离子通道疾病,RyR2基因突变是其最常见的突变形式。RyR2磷酸化异常引发的钙泄漏是CPVT发作的重要病理生理...     

Catecholaminergic polymorphic ventricular tachycardia

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a highly malignant form of arrhythmogenic disorder characterized by exercise- or emotional-induced polymorphic ventricular tachycardia in the absence of detectable structural heart disease. Because of the typical pattern of arrhythmias (bidirectional ventricular tachycardia and the occurrence and severity of arrhythmia correlated well with exercise workload) during exercise stress test, CPVT can be identified promptly. Molecular genetic screening of the genes encoding the cardiac ryanodine receptor and calsequestrin is critical to confirm uncertain diagnosis of CPVT. With the exception of beta-blockers, no pharmacologic therapy of proven effectiveness is available: although beta-blockers reduce the occurrence of ventricular tachycardia, 30% of patients treated with beta-blockers still experience cardiac arrhythmias and eventually require implantable cardioverter defibrillator implantation to prevent cardiac arrest.     

Catecholaminergic polymorphic ventricular tachycardia.

Catecholaminergic polymorphic ventricular tachycardia (VT) is a rare arrhythmogenic disease characterized by exercise- or stress-induced ventricular tachyarrhythmias, syncope, or sudden death, usually in the pediatric age group. Familial occurrence has been noted in about 30% of cases. Inheritance can be autosomal dominant or recessive, usually with high penetrance. The causative genes have been mapped to chromosome 1. Mutations of the cardiac ryanodine receptor gene (RyR2) have been identified in autosomal dominant pedigrees, while calsequestrin gene (CASQ2) mutations are seen in recessive cases. Ankyrin-B mutations may also be implicated in catecholaminergic polymorphic VT: mutations in this gene were previously linked to the long-QT 4 phenotype. Ventricular ectopy, bidirectional VT, and polymorphic VT occur in a predictable and progressive manner with increasing heart rate during exercise or isoproterenol infusion. Estimated mortality of untreated cases ranges from 30% to 50% before the age of 20-30 years according to family studies. Although beta-blocker therapy was considered to be effective in preventing clinical recurrence in the initial series, recent data show low efficacy. As there is a chance for sudden cardiac death if even a single dose of beta-blocker is missed, there is a trend toward implantation of defibrillators in more and more patients.     

Catecholaminergic polymorphic ventricular tachycardia,an update

Catecholaminergic polymorphic ventricular tachycardia is a rare devastating lethal inherited disorder or sporadic cardiac ion channelopathy characterized by unexplained syncopal episodes, and/or sudden cardiac death (SCD), aborted SCD (ASCD), or sudden cardiac arrest (SCA) observed in children, adolescents, and young adults without structural heart disease, consequence of adrenergically mediated arrhythmias: exercise‐induced, by acute emotional stress, atrial pacing, or β‐stimulant infusion, even when the electrocardiogram is normal. The entity is difficult to diagnose in the emergency department, given the range of presentations; thus, a familiarity with and high index of suspicion for this pathology are crucial. Furthermore, recognition of the characteristic findings and knowledge of the management of symptomatic patients are necessary, given the risk of arrhythmia recurrence and SCA. In this review, we will discuss the concept, epidemiology, genetic background, genetic subtypes, clinical presentation, electrocardiographic features, diagnosis criteria, differential diagnosis, and management.     

Catecholaminergic polymorphic ventricular tachycardia: recent mechanistic insights

Cardiac excitation-contraction coupling occurs by a calcium ion-mediated mechanism in which the signal of action potential is converted into Ca2+ influx into the cardiomyocytes through the sarcolemmal L-type calcium channels. This is followed by Ca2+-induced release of additional Ca2+ ions from the lumen of the sarcoplasmic reticulum into the cytosol via type 2 ryanodine receptors (RyR2). RyR2 channels form large complexes with additional regulatory proteins, including FKBP12.6 and calsequestrin 2 (CASQ2). Catecholamines, released into the body fluids during emotional or physical stress, activate Ca2+-induced Ca2+ release by protein kinase A-mediated phosphorylation of RyR2. Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an insidious, early-onset and highly malignant, inherited disorder characterized by effort-induced ventricular arrhythmias in the absence of structural alterations of the heart. At least some cases of sudden, unexplained death in young individuals may be ascribed to CPVT. Mutations of the RyR2 gene cause autosomal dominant CPVT, while mutations of the CASQ2 gene may cause an autosomal recessive or dominant form of CPVT. The steps of the molecular pathogenesis of CPVT are not entirely clear, but inappropriate "leakiness" of RyR2 channels is thought to play a role; the underlying mechanisms may involve an increase in the basal activity of the RyR2 channel, alterations in its phosphorylation status, a defective interaction of RyR2 with other molecules or ions, such as FKBP12.6, CASQ2, or Mg2+, or its abnormal activation by extra- or intraluminal Ca2+ ions. Beta-adrenergic antagonists have proven to be of value in prevention of arrhythmias in CPVT patients, but occasional treatment failures call for alternative measures. There is great interest at present for the development of novel antiarrhythmic drugs for CPVT, as the same approaches may be applied for treatment of more common forms of life-threatening arrhythmias, such as those arising during ischemia and heart failure.     

Catecholaminergic polymorphic ventricular tachycardia with associated sinus node dysfunction

An 11-year-old Nepalese male child presented with history of recurrent abrupt episodes of syncope for the last one year. There was no family history of sudden death at a young age in his family. ECG at base-line revealed an isorhythmic AV dissociation with a heart rate of 50 bpm and a normal QTc. Echocardiography of the heart was normal. His 24 hour holter study revealed frequent VPC's and episodes of polymorphic ventricular tachycardia. Exercise stress test provoked a polymorphic VT. On EP study, sinus node recovery time (SNRT) was prolonged and ventricular tachycardia (VT) was induced on Isoproterenol infusion. He was treated with a permanent pacemaker and beta-blocker.     

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.     

Catecholaminergic polymorphic ventricular tachycardia: electrocardiographic characteristics and optimal therapeutic strategies to prevent sudden death

Objective: To investigate the clinical outcome, ECG characteristics, and optimal treatment of catecholaminergic polymorphic ventricular tachycardia (CPVT), a malignant and rare ventricular tachycardia.