长QT综合征的危险分层

长QT综合征(Long QT Syndrome,LQTS)是指具有心电图上QT间期延长,T波异常,易产生室性心律失常、晕厥和猝死的一组综合征。按病因可分为获得性和遗传性两种类型[1]。本文综述对遗传性LQTS患者进行危险分层方面的研究进展。1 LQTS的临床表现 LQTS患者极易发生一种称做尖端扭转型室速(TdP)的室性心律失常(见图1)[2],后者可促进晕厥事件的发生。这种疾病常于青春期发病,典型地表现为剧烈运动与情绪波动后晕厥发作。在大多数情况下,这种心律失常可以自动终止,但TdP也可     

心电图在遗传性长QT综合征分型中的应用价值

国内遗传性长QT综合征(LQTS)的基因研究已经起步，但仍有较多单位不具备检测LQTS基因的完整技术条件。认识典型的LQT1，LQT2和LQT3的ST—T波图形，掌握这3种最常见LQTS基因类型的心电图特征，将有助于LQTS基因检测工作的开展和临床诊断治疗。因此根据ECG ST-T波形态初步判断LQTS基因型，有利于简化LQTS致病基因的筛选步骤，在节约时间和金钱方面，有着重要的临床意义。本文简要介绍这个领域的研究。     

正确认识及处理遗传性和获得性长QT综合征

本期专家论坛的专题是遗传性和获得性长QT综合征的诊断和各种治疗方法的当今观点，相信，这一讨论还能提高读者对心电图学分子机制的理解和心脏性晕厥一心脏猝死的防治有重要意义。     

先天性长QT综合征的QT间期不均一性:诊断上的意义

目的 通过分析QTc间期在长QT综合征（longQTsyndrome,LQTS)家系患者中的分布状况,评估QTc值在诊断LQTS上的意义。方法 研究对象为KVLQT1和HERG基因突变形成的LQT1和LQT2基因型患者,研究24个LQTS家系中374个成员的QTc值,包括181个基因携带者（83个KVLQT1和98个HERG）和193个非基因携带者,基因携带者中男性88人,女性93人;非基因携带者中男性97人,女性96人。将QTc的分布制成图表并按基因型进行比较,计算QTc值诊断LQTS的敏感性和特异性97人,女性96人。将QTc患者的QTc范围为0.41-0.62s,非基因携带者为0.36-0.47s。当女性QTc≥0.48s,男性QTc≥0.47s时可诊断为LQTS,相反,当女性QTc≤0.41s,男性≤0.40s时可排除LQTS。QTc值在0.42s至0.46s之间者,需要进一步检查来确诊。结论 LQT1和LQT2基因携带者QTc值范围较宽,使QTc值正常和临界的基因携带者在诊断上较为困难,对这类患者诊断时应特别注意。     

长QT综合征心电图和临床诊断

长QT综合征(LQTS)是指心电图上表现为QT间期延长、ST—T波异常、易产生恶性室性心律失常如尖端扭转型室速(Tdp)的一组综合征，临床上常有反复发作晕厥或猝死的病史以及家族史。     

家族性长QT综合征1例

长QT间期综合征,指具有心电图(ECG)上QT间期延长、室性心律失常、晕厥和猝死的1组综合征。多数学者认为是遗传性疾病。本文报告1例如下。 患儿男,3岁。因发热伴粘液脓血便3d入院。临床诊断:急性细菌性痢疾。入院时体检:T37.4℃,心律较慢,54次min。肝、肾功能正常,电解质、心肌酶谱正常,全胸片、心脏超声等检查亦无异常。图示:窦性心律,频率53次/min,     

特发性长QT综合征的遗传基础及临床意义

１概述：Ｊｅｖｅｌ和Ｌａｎｇｅ－Ｎｉｅｌｓｏｎ于１９５７年首先报道了特发性长ＱＴ综合征，临床特征为：（１）先天性神经性耳聋，（２）ＱＴ间期延长、Ｔ波异常，（３）在紧张和应激状态下出现恶性心律失常导致晕厥或猝死，称为Ｊｅｖｅｌ和Ｌａｎｇｅ－Ｎｉｅｌｓｏ...     

先天性长QT综合征心电图分析1例

患者女性、18岁，因“4h内突发晕厥3次”于2007年9月2日急诊入院。患者无器质性心脏病病史。入院查体：神志清，前额有5×2cm：皮肤擦伤，双肺呼吸音清，心界不大，各瓣膜听诊区无杂音。初步分析入院时心电图（图1A）：窦性心律，74bpm，QT／QTe700／752ms，V3-V6导联T波基底增宽，顶部变尖（似LQT1的T波改变），室性早搏。随后，患者情绪激动时，再次发作尖端扭转型室速（Tap），Tdp终止后，描记心电图（图1B）：窦性心律，103bpm，QT／QTc470／625ms，II、aVF、V2-V4导联可见明显双峰T波（箭头指示），频发室性早搏。     

长QT综合征的研究进展

长QT综合征(longQTsyndrome,LQTS)是在心电图上表现为QT间期延长,容易发生各种室性心律失常,而在临床上表现为晕厥和猝死的一组综合征。按病因可分为遗传性和获得性两种。近年来,随着分子生物学技术的发展,在遗传性LQTS的诊断和危险度分层方面有不少进展,从而可能对今后治疗的选择产生积极的影响。     

The long QT interval syndrome

The syndrome of long QT interval frequently follows to syncope or a sudden cardiac death on the basis of originated polymorphic ventricular tachycardia of the "torsade de pointes" type. The prolongation of the QT interval in the hereditary form is based on mutation of the genes responsible for the formation of sodium and potassium channels. The authors analyze the occurrence, clinical findings, therapy and genetic and electropathophysiological connections of the most frequently occurring genotype LQT1, LQT2 and LQT3 as well as the acquired forms of the syndrome of long QT interval.     

Brugada综合征合并先天性长QT综合征一例

目的报告1例反复发作晕厥伴胸前导联J—ST—T显著抬高患者的临床过程。方法1例15岁男孩反复于夜间卧床休息时发生晕厥，对该患者及其父母进行病史询问、体格检查、心电图及超声心动图检查，并行普罗帕酮激发试验。对患者进行冠状动脉，左、右心室造影和心内电生理检查。结果患者及其父母无器质性心脏病依据，无阳性猝死家族史。患者直立倾斜试验阴性，冠状动脉和左、右心室造影正常，心内电生理检查未发现异常，未诱发室性心律失常。患者基础心电图胸前导联J-ST—T显著抬高，晕厥后窦性心动过速时J—ST—T降低伴QTc延长。静脉注射普罗帕酮70mg后胸前导联J—ST与T波第二峰进一步抬高。患者母亲基础心电图ST—T类似于LQT3，但QTc正常。患者父母在静脉注射普罗帕酮70mg后胸前导联ST—T均进一步抬高。结论该患者心电图不同于已报道的Brugada综合征合并LQT3，可能为新的SCN5A基因突变导致的一种新的表型。     

Famotidine and long QT syndrome

Numerous drugs have been implicated in causing a prolonged QT interval and Torsades de pointes. However, the association of famotidine and acquired long QT syndrome has rarely been reported. We report 2 cases of famotidine-associated acquired long QT syndrome.     

Inherited long QT syndrome

Inherited long QT syndrome (LQTS) is characterized by a prolonged ventricular repolarization (QTc interval) and symptoms (syncope, sudden cardiac arrest) due to polymorphic ventricular arrhythmias. As of today, 13 different cardiac ion channel genes have been associated with congenital LQTS. The most common ones are due to KCNQ1 (LQT-1), KCNH2 (LQT-2), and SCN5A (LQT-3) gene mutations and account for up to 75?% of cases. Typical clinical findings are an increased QT interval on the surface electrocardiogram, specifically altered T wave morphologies, polymorphic ventricular arrhythmias, or an indicative family history. Recently, in the HRS/EHRA expert consensus statement, comprehensive genetic testing of major LQTS genes was recommended for index patients for whom there is a strong clinical suspicion of LQTS. Overall, antiadrenergic therapy, in particular ??-receptor blockers, has been the mainstay of therapy and has significantly reduced cardiac events. For high-risk patients, an implantable cardioverter defibrillator (ICD) is recommended. Importantly, lifestyle modification and avoidance of arrhythmia triggers are additional important approaches.     

Management of long QT syndrome

Congenital long QT syndrome (LQTS) is a genetic disorder characterized by prolongation of the QT interval on the electrocardiogram and by life-threatening cardiac arrhythmias, occurring especially during conditions of increased sympathetic activity. Existing therapies are very effective, but mortality is high among untreated, symptomatic individuals. The identification of several of the genes responsible for LQTS and the realization that they all encode cardiac ion-channels has represented a landmark finding. This advance has fostered novel genotype-phenotype studies that are providing unique insight into how close the relationship can be between molecular biology and clinical cardiology. LQTS represents a paradigm for sudden cardiac death. Indeed, the growing knowledge developed for LQTS is likely to provide the key to understanding the genetic propensity to sudden death in patients with more-common cardiovascular diseases. The data presented here illustrate how the treatment of LQTS is rapidly evolving toward a highly individually tailored approach on the basis of patient-specific genetic information.     

长QT综合征的治疗进展

长QT综合征（long QT syndrome,LQTS）属于离子通道病.分先天性和获得性两种.前者由编码心脏离子通道蛋白的基因突变所致,后者产生于药物、电解质不平衡及器质性心脏病对心脏离子通道的影响.其心电图特点为QT间期延长,T波改变以及尖端扭转性室性心动过速（室速）为特点的多形室速（TdP）,导致心室颤动（室颤）甚至引起心脏性晕厥和猝死.LQTS虽然不是临床常见病,但并非罕见.