特发性异常J波与Brugada综合征的临床及心电图特征

目的探讨特发性异常J波与Brugada综合征的临床及心电学特点。方法对特发性异常J波与Brugada综合征各8例进行分析。结果①特发性异常J波在肢导联或(和)胸导联可见正向异常J波[除aVR(部分患者aVL)外],其波幅较低而分布较广,一般V1~V2导联不出现J波,若出现则JV1~V2R,TV1~V2(V3)倒置或直立。两者均易诱发多形性室性心动过速及/或心室颤动而致死。结论异常J波和Brugada综合征及Brugada样心电图象是具有不同临床及心电学特点的临床病症。     

异常J波、Brugada综合征与特发性Brugada心电图征的临床与心电图特征

对比分析异常J波 2 1例、Brugada综合征 8例与特发性Brugada心电图征 11例的临床及心电学特点。结果 :①特发性异常J波在肢导联或 (和 )胸导联可见正向异常J波 [除aVR(部分患者aVL)外 ],其波幅较低而分布较广 ,一般V1～V2 导联不出现J波 ,若出现则JV1 ～V2R ,TV1 ～V2 (V3) 倒置或直立 ,前者常出现恶性快速性室性心律失常而发生晕厥或猝死 ,后者则无晕厥或猝死及恶性心律失常发作。结论 :异常J波和Brugada综合征及特发性Brugada心电图征是具有不同临床及心电学特点的临床实体。     

Brugada波与特发性J波

一、Brugada波Brugada波的典型心电图表现是 ,右胸前V1～V3 导联的ST段抬高和右束支阻滞共同称为Bru gada波。因此 ,正确识别Brugada波对诊断Brugada综合征是十分重要的。1.Brugada波的典型心电图特点⑴右胸前导联的ST段抬高 :右心室肌的期前复极和 或传导延迟引起的右胸前导联V1～V3 的ST段抬高 ,呈穹隆型或马鞍型及下斜型两种表现 ,偶尔有电轴左偏 ,并伴有T波倒置 ,某些病例可在其他导联 (V4)上出现ST段的抬高 ,而且绝大多数Brugada波并无对应导联的ST段下移改变 ,QT间期并不延长。ST段抬高的诊断标准是 ,V1～V3 导联上J点至…     

Brugada综合征的诊断与治疗

仔细分析后可以发现,Brugada综合征和预激综合征有异曲同工之处.两者都有特征很强的心电图表现,预激综合征心电图的表现为δ波、短PR间期和QRS波宽大畸形三联征;而Brugada综合征心电图的表现为右胸V1～V3导联的类右束支阻滞、ST段抬高和T波倒置三联征.     

不同原因右胸导联T波倒置的比较

探讨不同原因右胸导联T波倒置的心电学特征,以利于对不同特征右胸导联T波倒置的原因识别。对74例由不同原因所致右胸导联T波倒置患者常规12导联心电图T波倒置的分布规律、倒置的深度以及是否同时伴有ST段改变、其它导联的T波倒置及其演变过程进行分析。结果:①右室起搏后电张调整性T波呈V1~V2V5~V6,并伴Ⅱ、Ⅲ、aVF导联T波倒置,不伴ST段改变。②急性肺栓塞后TV1~V3倒置往往在发病1~2h后按一定的顺序相继出现,依次为TV1→TV2→TV3→TV4;倒置深度V1>V2>V3>V4,随病情好转,其T波恢复的顺序则相反。③Brugada综合征或Brugada心电图征呈TV1>TV2>TV3伴STV1~V3下斜型或马鞍型抬高及右束支阻滞或类右束支阻滞,R′>R。④妊娠晚期亦表现为TV1~V3倒置,倒置深度V1>V2>V3,与急性肺栓塞后的T波改变类似。结论:不同原因右胸导联T波倒置的心电学特征亦异,认识这些特征,有利于对其病因的识别。     

J波与J波综合征

J波是指心电图上QRS波与ST段之间的圆顶状或驼峰状电位变化。新近临床研究表明，在早期复极综合征、Brugada综合征和特发性心室颤动等心电图中，均存在J波形态、时限和幅度的显著改变，上述与J波密切相关的一系列临床综合征统称为J波综合征。本文详尽阐述了J波的细胞电生理和离子流机制，分析了早期复极综合征、Brugada综合征、心电图下壁导联高大J波相关的心脏性猝死的临床特点及内在机制。     

Brugada波与Brugada综合征

Brugada综合征是一编码离子通道基因异常所致的家族性原发心电活动紊乱性疾病。自 1991年BrugadaP和BrugadaJ报告于临床以来 ,由于其右胸前导联特征性心电图改变和猝死病症 ,所以多年来一直是心血管病基础和临床研究的热点。 2 0 0 1年HurstJW将Brugada描述的V1～V3 导联特征性心电图改变称为“Brugada波”。本文仅对Brugada波的特点、鉴别和与Brugada综合征的关系等临床医师关注的具体问题简要讨论如下。一、Brugada波的心电图特点1、典型心电图表现Brugada波由抬高的ST段和“右束支阻滞”(RBBB)共同组成 ,典型者常伴倒置的T波 ,…     

国人Brugada综合征临床特征的Meta分析

目的了解国人Brugada综合征的主要临床特征。方法对1998～2002年国内期刊报道的26例Brugada综合征的临床和心电图资料的临床特征作Meta分析。结果患者主要见于青壮年男性,猝死发生时记录到可救治的心室颤动和多形性室性心动过速;心电图呈类右束支传导阻滞型,V1、V2导联以ST段下斜型抬高、T波倒置为主,有家族史者在心律失常发生前出现先兆者明显低于无家族史者(30%比62.5%,P<0.05)。结论国人Brugada综合征以青壮年男性为主,心电图表现与文献资料相似。有家族史者比无家族史者病情凶险。     

Brugada综合征心电图的发生机制

Brugada综合征心电图的发生机制的认识过程 ,也是先从临床现象 (195 3- )到细胞电生理机制(1995 - ) ,再深入到分子生物学的离子流和基因遗传学机制 (1998- )的研究过程。 195 3年起 ,报导健康人群心电图有时表现为右心前导联V1～V3 ST段提高和T波倒置 ;伴或不伴有RBBB ,并注意到可能与心脏猝死有关 ;1991年西班亚学者Brugada兄弟俩Pedro和Josep在NASPE报导了 4例特殊临床和心电图综合征 ,并于 1992年在JACC正式全文描述了无器质性心脏病伴有心脏猝死和猝死存活的 8例病人 ,此后人们将此征候群称为Brugada综合征[1-2 ] 。以Dr .Ch…     

Brugada综合征心电图的药物激发试验

近年来 ,作为特发性心室颤动的一种特殊表现—Brugada综合征 ,正越来越引起人们的重视 ,它是一种基因决定的心电疾病 ,其特征性心电图表现为V1～V3 导联出现ST段抬高、T波倒置及右束支阻滞 ,有人称之“心电图右胸导联三联征”。但只有6 0 %的病例具备此典型心电图表现 ,其余 4 0 %患者呈隐匿性状态 ,或异常心电图自发性正常化呈间歇性过程 ,同一患者在不同时间其心电图异常程度、形态亦可不一致。影响以上心电图形态多变性、多态性的因素 ,除了自主神经调节及抗心律失常药物外 ,还与以下因素有关 :①心率 :一般情况下 ,心率快 ,ST段抬高…     

Is there an overlap between Brugada syndrome and arrhythmogenic right ventricular cardiomyopathy/dysplasia?

The Brugada syndrome is a congenital syndrome displaying an autosomal dominant mode of transmission in patients with a structurally normal heart. The disease has been linked to mutations in SCN5A , a gene located on the short arm of chromosome 3 (p21-24) that encodes for the alpha subunit of the sodium channel. The syndrome is characterized by a dynamic ST-segment elevation (accentuated J wave) in leads V 1 to V 3 of the ECG followed by negative T wave. Right bundle-branch block of varying degrees is observed in some patients. The syndrome is associated with syncope and a relatively high incidence of sudden cardiac death secondary to the development of polymorphic ventricular tachycardia that may degenerate into ventricular fibrillation. An acquired form of the Brugada syndrome is also recognized, caused by a wide variety of drugs and conditions that alter the balance of currents active during the early phases of the action potential. Among patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia, there is a subpopulation with a clinical and electrocardiographic pattern similar to that of the Brugada syndrome. These cases of arrhythmogenic right ventricular cardiomyopathy/dysplasia are thought to represent an early or concealed form of the disease. This review examines the overlap between these 2 syndromes.     

J-wave syndromes. from cell to bedside

The J wave, a deflection that follows the QRS complex of the surface electrocardiogram, is usually partially buried in the R wave in humans, appearing as a J-point elevation. An early repolarization (ER) pattern characterized by J-point elevation, slurring of the terminal part of the QRS, and ST-segment elevation has long been recognized and considered to be totally benign. Recent studies have presented evidence demonstrating that an ER pattern in inferior leads or inferolateral leads is associated with increased risk for life-threatening arrhythmias, named early repolarization syndrome. Early repolarization syndrome and Brugada syndrome share similar electrocardiographic characteristics, clinical outcomes, risk factors, as well as a common arrhythmic platform related to amplification of I_to-mediated J waves. Although Brugada syndrome and early repolarization syndrome differ with respect to the magnitude and lead location of abnormal J wave manifestation, they can be considered to represent a continuous spectrum of phenotypic expression, termed J-wave syndromes. Early repolarization syndrome has been proposed to be divided into 3 subtypes: type 1, displaying an ER pattern predominantly in the lateral precordial leads, is prevalent among healthy male athletes and rarely seen in ventricular fibrillation survivors; type 2, displaying an ER pattern predominantly in the inferior or inferolateral leads, is associated with a higher level of risk; whereas type 3, displaying an ER pattern globally in the inferior, lateral, and right precordial leads, is associated with the highest level of risk for development of malignant arrhythmias and is often associated with ventricular fibrillation storms.     

Presence of intermittent J waves in multiple leads in relation to episode of atrial and ventricular fibrillation

Brugada syndrome is characterized by J wave and ST-segment elevation of right precordial leads and causes idiopathic ventricular fibrillation. We experienced a patient of Brugada syndrome with prominent J wave and ST-segment elevation not only in V(1) to V(3) but also in many leads. He suffered spontaneous ventricular fibrillation and resuscitated by direct current. He has no structural heart disease.     

Early repolarization syndrome: is it always benign?

Early repolarization syndrome is a well-recognized idiopathic electrocardiographic phenomenon characterized by prominent J wave and ST-segment elevation predominantly in left precordial leads. The syndrome shares remarkable cellular, ionic, and electrocardiographic similarities with the Brugada syndrome and idiopathic ventricular fibrillation (a variant of the Brugada syndrome with ST-segment elevation in inferior leads). Although early repolarization syndrome is considered a benign entity, its arrhythmogenic potential still remains unknown. We report the case of a 39-year-old male with a family history of sudden death and an electrocardiogram consistent with early repolarization syndrome. Diagnostic dilemmas are discussed.     

ECG Repolarization Waves: Their Genesis and Clinical Implications

The electrocardiographic (ECG) manifestation of ventricular repolarization includes J (Osborn), T, and U waves. On the basis of biophysical principles of ECG recording, any wave on the body surface ECG represents a coincident voltage gradient generated by cellular electrical activity within the heart. The J wave is a deflection with a dome that appears on the ECG after the QRS complex. A transmural voltage gradient during initial ventricular repolarization, which results from the presence of a prominent action potential notch mediated by the transient outward potassium current (I_to) in epicardium but not endocardium, is responsible for the registration of the J wave on the ECG. Clinical entities that are associated with J waves (the J‐wave syndrome) include the early repolarization syndrome, the Brugada syndrome and idiopathic ventricular fibrillation related to a prominent J wave in the inferior leads. The T wave marks the final phase of ventricular repolarization and is a symbol of transmural dispersion of repolarization (TDR) in the ventricles. An excessively prolonged QT interval with enhanced TDR predisposes people to develop torsade de pointes. The malignant “R‐on‐T” phenomenon, i.e., an extrasystole that originates on the preceding T wave, is due to transmural propagation of phase 2 reentry or phase 2 early afterdepolarization. A pathological “U” wave as seen with hypokalemia is the consequence of electrical interaction among ventricular myocardial layers at action potential phase 3 of which repolarization slows. A physiological U wave is thought to be due to delayed repolarization of the Purkinje system.     

Right ventricular electrocardiographic leads for detection of Brugada syndrome in sudden unexplained death syndrome survivors and their relatives

BACKGROUND: Sudden unexplained death syndrome (SUDS) is a sudden death syndrome in previously healthy Southeast Asian young adults without any structural causes of death. Many SUDS survivors show electrocardiographic (ECG) evidence of RSR' and ST elevation in leads V1 to V3, which is similar to the ECG pattern in Brugada syndrome. However, in many cases transient normalization of the ECG does not make diagnosis with standard 12-lead ECG possible. HYPOTHESIS: To overcome this problem, we utilized the new right ventricular ECG leads to detect the Brugada syndrome in SUDS survivors. METHODS: The subject was a Thai male patient who presented with a SUDS-like syncopal attack. He had cardiac arrest due to idiopathic ventricular fibrillation. RESULTS: Post-resuscitation standard 12-lead ECG showed no diagnostic features of Brugada syndrome. However, ECG patterns of RSR' and ST elevations typical for Brugada syndrome could be detected at the higher intercostal space leads V1 to V3. We observed similar findings in 2 of the other 10 SUDS survivors and 4 of 23 healthy family members. CONCLUSIONS: Our data suggest that these new right ventricular leads ECG may be helpful in detecting Brugada syndrome in SUDS survivors and their relatives.     

Genetic, molecular and cellular mechanisms underlying the J wave syndromes

An early repolarization (ER) pattern in the ECG, distinguished by J-point elevation, slurring of the terminal part of the QRS and ST-segment elevation has long been recognized and considered to be a benign electrocardiographic manifestation. Experimental studies conducted over a decade ago suggested that some cases of ER may be associated with malignant arrhythmias. Validation of this hypothesis was provided by recent studies demonstrating that an ER pattern in the inferior or inferolateral leads is associated with increased risk for life-threatening arrhythmias, termed ER syndrome (ERS). Because accentuated J waves characterize both Brugada syndrome (BS) and ERS, these syndromes have been grouped under the term "J wave syndromes". ERS and BS share similar ECG characteristics, clinical outcomes and risk factors, as well as a common arrhythmic platform related to amplification of I(to)-mediated J waves. Although BS and ERS differ with respect to the magnitude and lead location of abnormal J wave manifestation, they can be considered to represent a continuous spectrum of phenotypic expression. Although most subjects exhibiting an ER pattern are at minimal to no risk, mounting evidence suggests that careful attention should be paid to subjects with "high risk" ER. The challenge ahead is to be able to identify those at risk for sudden cardiac death. Here I review the clinical and genetic aspects as well as the cellular and molecular mechanisms underlying the J wave syndromes.