Ventricular flutter triggered by fever in a patient with Brugada syndrome

Brugada syndrome is a clinical-electrocardiographic entity predisposing to malignant ventricular arrhythmias. The typical arrhythmia is polymorphic ventricular tachycardia, which can potentially degenerate to ventricular fibrillation. Monomorphic ventricular tachycardia is uncommon. Our group is reporting the case of a 39-year-old man with known Brugada syndrome who developed ventricular flutter while febrile. Fever has previously been shown to unmask Brugada changes and to induce ventricular arrhythmias. The appearance of monomorphic ventricular tachycardia potentially attributable to sodium-channel dysfunction further confounds the mechanism of arrhythmogenesis in Brugada syndrome. This curious occurrence further underlines the likely complex nature of arrhythmogenesis in Brugada syndrome.     

An atypical case of Brugada syndrome

Polymorphic ventricular tachycardia and ventricular fibrillation are the most common arrhythmias in Brugada syndrome causing syncope or sudden death. Sustained monomorphic ventricular tachycardias are rare in this context. We report of a patient with syncopal episodes due to episodes of sustained ventricular tachycardia, where a Type-I Brugada pattern was revealed after pharmacological provocation with procainamide.     

Brugada syndrome presenting with sustained monomorphic ventricular tachycardia

Typically Brugada syndrome presents with either ventricular fibrillation or polymorphic ventricular tachycardia that may result in sudden death or syncope in patients without any structural heart disease. We report the case of a patient with Brugada syndrome who presented atypically with recurrent presyncope following physical exertion due to sustained monomorphic ventricular tachycardia, which appeared to be sensitive to both adenosine and catecholamine. He refused ICD implantation but remained asymptomatic on treatment with a beta-blocker.     

Syncopal monomorphic ventricular tachycardia with pleomorphism, sensitive to antitachycardia pacing in a patient with Brugada syndrome.

Polymorphic ventricular tachycardia and ventricular fibrillation are the most common arrhythmias in Brugada syndrome, causing syncope or sudden death. Sustained monomorphic ventricular tachycardias are rare in this context. We report the case of a 41-year-old man with repetitive syncopal episodes and an ajmaline-induced characteristic Brugada ECG pattern, in whom episodes of monomorphic ventricular tachycardia with pleomorphism and response to ventricular pacing were documented.     

Heterogeneity and cardiac arrhythmias: An overview

This lecture examines the hypothesis that amplification of spatial dispersion of repolarization in the form of transmural dispersion of repolarization (TDR) underlies the development of life-threatening ventricular arrhythmias associated with inherited ion channelopathies, including the long QT, short QT, and Brugada syndromes as well as catecholaminergic polymorphic ventricular tachycardia. In the long QT syndrome, amplification of TDR often is secondary to preferential prolongation of the action potential duration of M cells, whereas in Brugada syndrome, it is thought to be due to selective abbreviation of the action potential duration of right ventricular epicardium. In the short QT syndrome, preferential abbreviation of action potential duration of either endocardium or epicardium appears to be responsible for amplification of TDR. In catecholaminergic polymorphic ventricular tachycardia, reversal of the direction of activation of the ventricular wall is responsible for the increase in TDR. Thus, the long QT, short QT, Brugada, and catecholaminergic ventricular tachycardia syndromes are pathologies with very different phenotypes and etiologies. However, these syndromes share a common final pathway in their predisposition to sudden cardiac death.     

Spontaneous right ventricular outflow tract tachycardia in a patient with Brugada syndrome

We report the case of a 28-year-old man with no structural heart disease, who exhibited clearly augmented ST segment elevation in the right precordial leads, followed by induction of spontaneous right ventricular outflow tract tachycardia with intravenous administration of Class IA antiarrhythmic drugs. The electrophysiologic mechanism of this tachycardia was thought to be triggered activity due to delayed afterdepolarizations. Due to the existence of substrates that were similar to Brugada syndrome combined with right ventricular outflow tract tachycardia, this case may represent a subtype of Brugada syndrome.     

Sudden death and ion channel disease: pathophysiology and implications for management

The underlying aetiology of sudden arrhythmic death syndrome is predominantly inherited cardiac disease, and 'channelopathies' (cardiac ion channel disease) are the most common detectable cause of death. This heterogeneous group includes Brugada syndrome, long QT syndrome and catecholaminergic polymorphic ventricular tachycardia. Common features include variable penetrance, sudden death due to ventricular arrhythmias, and the absence of structural heart disease. The understanding of cardiac ion channel disease has been revolutionised by genetics. At present, genotype contributes to risk stratification in Brugada syndrome, long QT syndrome and catecholaminergic polymorphic ventricular tachycardia, and the future promises management tailored to the genetic diagnosis.     

Brugada and Long QT‐3 Syndromes: Two Phenotypes of the Sodium Channel Disease

Brugada and long QT‐3 syndromes are two allelic diseases caused by different mutations in SCN5A gene inherited by an autosomal dominant pattern with variable penetrance. Both of these syndromes are ion channel diseases of the heart manifest on surface electrocardiogram by ST‐segment elevation in the right precordial leads and prolonged QT_c interval, respectively, with predilection for polymorphic ventricular tachycardia and sudden death, which may be the first manifestation of the disease. Brugada syndrome usually manifests during adulthood with male preponderance, whereas long QT3 syndrome usually manifests in teenage years, although it can also manifest in adulthood. Class IA and IC antiarrhythmic drugs increase ST‐segment elevation and predilection for polymorphic ventricular tachycardia and ventricular fibrillation in Brugada syndrome, whereas these agents shorten the repolarization and QT_c interval, and thus may be beneficial in long QT‐3 syndrome. Beta‐blockade also increases the ST‐segment elevation in Brugada syndrome but decreases the dispersion of repolarization in long QT‐3 syndrome. Mexiletine, a class IB sodium channel blocker decreases QT_c interval as well as dispersion of repolarization in long QT‐3 syndrome but has no effect on Brugada syndrome. The only effective treatment available at this time for Brugada syndrome is implantable cardioverter defibrillator, although repeated episodes of polymorphic ventricular tachycardia can be treated with isoproterenol. In symptomatic patients of long QT‐3 syndrome in whom the torsade de pointes is bradycardia‐dependent or pause‐dependent, a pacemaker could be used to avoid bradycardia and pauses and an implantable cardioverter defibrillator is indicated where arrhythmia is not controlled with pacemaker and beta‐blockade. However, the combination of new devices with pacemaker and cardioverter‐defibrillator capabilities appear promising in these patients warranting further study.     

Brugada综合征患者的心电图及临床特点分析

目的分析Brugada综合征患者的心电图及临床特点。方法对我院近5年诊断的8例Brugada综合征住院患者的心电图及临床情况进行长期随访观察。结果8例Brugada综合征患者均为男性，年龄平均（40±13）岁。心电图Ⅰ型Brugada波者3例，Ⅱ型4例，Ⅲ型1例；Brugada波具有多变性，提高肋间描记右胸导联心电图可显现Brugada波或使其更明显。8例中4例有猝死家族史，5例有晕厥史，3例在住院期间发生室速／室颤，随访期间2例猝死。结论心电图Brugada波（尤其Ⅰ型）是诊断Brugada综合征的必要条件，明确诊断Brugada综合征尚需联合其他几项临床指标；Brugada综合征患者猝死的风险高，消除晕厥或室速／室颤的诱因是预防的关键。     

Exercise-induced ventricular tachycardia associated with J point ST-segment elevation in inferior leads in a patient without apparent heart disease: a variant form of Brugada syndrome?

Exercise-induced monomorphic ventricular tachycardia originating in the right ventricular outflow tract without evidence of structural heart disease can be idiopathic or can be the harbinger of structural abnormalities such as arrhythmogenic right ventricular dysplasia. Recently, the so-called variant Brugada syndrome has been reported in very few cases in the literature and is much less electrophysiologically defined in terms of its clinical significance. We present the case of a 21-year-old man with exercise-induced monomorphic ventricular tachycardia (left bundle-branch block/right axis deviation), without detectable structural heart disease, with evidence of J point and ST-segment elevation in electrocardiogram leads II, III, and aVF after intravenous administration of propafenone. This is followed by a brief discussion on the new concept of “variant Brugada syndrome,” drug-induced electrocardiographic changes, normal-variant repolarization abnormality, and idiopathic right ventricular outflow tract tachycardia.     

Brugada syndrome associated with supraventricular tachycardia

We report the case of a patient with Brugada syndrome and a history of palpitations who presented with an episode of syncope and developed supraventricular tachycardia in the electrophysiological study. The patient was treated with radiofrequency ablation for the supraventricular tachycardia and an implantable cardioverter defibrillator for the Brugada syndrome. At 18?months following implantation of the defibrillator an electrical storm with ventricular fibrillation episodes occurred followed by appropriate discharges of the defibrillator.     

Monomorphic ventricular tachycardia due to Brugada syndrome successfully treated by hydroquinidine therapy in a 3-year-old child

Mutations in the SCN5A gene can cause Brugada syndrome, a genetically inherited form of idiopathic ventricular fibrillation. We describe the case of a 3-year-old child with a structurally normal heart presenting with monomorphic ventricular tachycardia. Her electrocardiogram suggested a Brugada syndrome and the diagnosis was confirmed by the identification of a Brugada syndrome in her mother and in two other family members. Genetic study led to the identification of a c.2516T-->C SCN5A mutation. The child was treated with quinidine therapy without recurrence of arrhythmic events for a time period of 16 months.     

The Brugada syndrome: clinical,electrophysiologic and genetic aspects

This review deals with the clinical, basic and genetic aspects of a recently highlighted form of idiopathic ventricular fibrillation known as the Brugada syndrome. Our primary objective in this review is to identify the full scope of the syndrome and attempt to correlate the electrocardiographic manifestations of the Brugada syndrome with cellular and ionic heterogeneity known to exist within the heart under normal and pathophysiologic conditions so as to identify the cellular basis and thus potential diagnostic and therapeutic approaches. The available data suggest that the Brugada syndrome is a primary electrical disease resulting in abnormal electrophysiologic activity in right ventricular epicardium. Recent genetic data linking the Brugada syndrome to an ion channel gene mutation (SCN5A) provides further support for the hypothesis. The electrocardiographic manifestations of the Brugada syndrome show transient normalization in many patients, but can be unmasked using sodium channel blockers such as flecainide, ajmaline or procainamide, thus identifying patients at risk. The available data suggest that loss of the action potential dome in right ventricular epicardium but not endocardium underlies the ST segment elevation seen in the Brugada syndrome and that electrical heterogeneity within right ventricular epicardium leads to the development of closely coupled premature ventricular contractions via a phase 2 reentrant mechanism that then precipitates ventricular tachycardia/ventricular fibrillation (VT/VF). Currently, implantable cardiac defibrillator implantation is the only proven effective therapy in preventing sudden death in patients with the Brugada syndrome and is indicated in symptomatic patients and should be considered in asymptomatic patients in whom VT/VF is inducible at time of electrophysiologic study.     

Concurrent long QT and Brugada syndrome in a single patient]

We present a 61-year-old patient with previous cardiac arrest and frequent syncopal spells. ECG showed a typical Brugada pattern and a QTc interval of 425 ms. During programmed ventricular stimulation a self-limited syncopal polymorphic ventricular tachycardia was induced. On diagnosis of the Brugada syndrome an implantable cardioverter defibrillator was implanted. Two days later two episodes of polimorphic ventricular arrhythmia were converted by the device. The ECG at this time showed a prolonged QTc of 500 ms in addition to a typical Brugada pattern. Atenolol was started and after a 36-month follow-up the patient has remained asymptomatic without arrhythmic events. In conclusion, this patient has the Brugada syndrome and also fulfills the clinical and ECG characteristics of the Long QT syndrome. These findings suggest a genetic link between the two syndromes.     

Brugada syndrome with monomorphic ventricular tachycardia in a one-year-old child.

A one-year-old child with a structurally normal heart presented with monomorphic ventricular tachycardia. Electrocardiogram in sinus rhythm showed right bundle branch block with ST segment elevation suggesting a diagnosis of Brugada syndrome. At a later date, when the ST segment was isoelectric. intravenous procainamide caused ST elevation typical of Brugada syndrome.     

Brugada syndrome: an unusual cause of convulsive syncope

A patient who presented with a new apparent seizure was found to have abnormal electrocardiographic findings, with classic features of the Brugada syndrome. He had spontaneous episodes of nonsustained ventricular tachycardia, easily inducible ventricular fibrillation at electrophysiological study in the absence of structural heart disease, and a negative neurological evaluation. These findings suggested that sustained ventricular arrhythmias known to be associated with the Brugada syndrome and resultant cerebral hypoperfusion, rather than a primary seizure disorder, were responsible for the event. Patients with the Brugada syndrome often present with sudden death or with syncope resulting from ventricular arrhythmias. In consideration of its variability in presentation sometimes mimicking other disorders, primary care physicians and internists should be aware of its often transient electrocardiographic features.     

Brugada type 1 electrocardiographic pattern induced by severe hyponatremia

Brugada syndrome is characterized electrocardiographically by ST segment elevation in the right precordial leads, followed by a negative T wave unrelated to ischemia, electrolyte disturbance or drug effects and prone to rapid polymorphic ventricular tachycardia capable of degenerating into ventricular fibrillation. The ECG pattern may be dynamic and is often concealed. Sodium channel blockers, drugs, electrolyte imbalances, fever and several other clinical circumstances are recognized inducers of a Brugada type 1 ECG in susceptible patients. We describe a case of a Brugada type 1 ECG pattern induced by severe hyponatremia.     

Brugada Syndrome,Exercise, and Exercise Testing

There are few data on the risk of exercise and the role of exercise stress testing in Brugada syndrome. We sought to address this deficiency using a systematic literature review. We identified 98 English‐language articles possibly addressing exercise in Brugada syndrome by searching PubMed and Google Scholar from January 1990 through November 2013 using the keywords “Brugada syndrome,” “exercise,” “exercise testing,” and “syncope” alone and in combinations. Abstracts were reviewed, and those articles pertaining to Brugada syndrome and exercise were reviewed in full. We identified 18 articles reporting on Brugada syndrome and exercise. This pool included 2 large studies of 93 and 50 Brugada subjects undergoing exercise testing, plus 16 case reports. There were no reports of exercise‐related sudden death, but there were 4 cases of syncope after exercise. We identified 166 Brugada patients who underwent exercise testing. During exercise testing, there were 2 reports of ventricular tachycardia and 1 report of multiple ventricular extrasystoles. ST‐segment elevation increased (ST augmentation) during the early recovery phase of exercise in 57% of patients. Exercise unmasked a Brugada electrocardiographic pattern in 5 patients. Exercise is associated with syncope and ST augmentation after exercise and may be helpful in unmasking Brugada syndrome. There are insufficient data on the risks of exercise in Brugada syndrome to make recommendations for exercise, but the observations that exercise can worsen the ST abnormalities in Brugada and produce ventricular arrhythmias suggest that patients with Brugada syndrome should be restricted from vigorous exercise.     

Successful use of quinine in the treatment of electrical storm in a child with Brugada syndrome

A 10-year-old girl developed life-threatening recurrent polymorphic ventricular tachycardia following surgical closure of a simple secundum atrial septal defect. Post hoc analysis of a Holter recording suggested Brugada syndrome. After managing the acute phase, a dual chamber defibrillator was implanted. One week later she experienced VF storm, needing 96 appropriate shocks within a few hours. Quinidine, by virtue of its I(to) blocking property, is the only drug reported to be useful in managing VF storm in Brugada syndrome. Nonavailability of quinidine led us to try its diastereomer, intravenous quinine, which succeeded in controlling the ventricular tachycardia. Arrhythmia storm in the setting of ion channelopathy can be difficult to manage, and sometimes requires innovative therapies.