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Query: UMLS:C0018799 (heart disease)
 34,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This review deals with the clinical, basic and genetic aspects of recently highlighted form of idiopathic ventricular fibrillation known as the Brugada syndrome. The available data suggest that the Brugada syndrome is a primary electrical disease resulting in abnormal electrophysiological activity in the right ventricular epicardium. Diagnosis is based on the presence of an ST elevation in the anteroseptal territory and a right branch block. No underlying dysarrhythmic condition or arrhythmogenic heart disease can be detected. The available data suggest that less of the action potential dome in the 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. Brugada syndrome is a recently discovered hereditary condition with a probably underestimated prevalence. Systematic family studies have demonstrated an autosomal dominant inheritance. The characteristic electrocardiographic anomalies can be transitory and may be unmasked by sensitization tests. The only currently treatment is the implantable defibrillator programmed to prevent sudden death by ventricular fibrillation and it is indicated in symptomatic patients and should be considered in asymptomatic patients in whom ventricular tachycardia/ventricular fibrillation is inducible by electrophysiologic study.
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PMID:[The Brugada syndrome. A predicted sudden juvenile death]. 1071 41

We present the case of a 13-year-old boy with an episode of aborted sudden death, absence of structural heart disease, and a characteristic ECG pattern of right bundle branch block with persistent ST-segment elevation in the right precordial leads, in whom a monomorphic sustained ventricular tachycardia developed spontaneously after the administration of ajmaline. This effect may be related to an increased inhomogeneity of repolarization mediated by the drug and demonstrates the arrhythmogenic potential of Class I antiarrhythmic drugs in patients with Brugada syndrome.
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PMID:Spontaneous sustained monomorphic ventricular tachycardia after administration of ajmaline in a patient with Brugada syndrome. 1075 Jan 26

The authors present a patient with a specific ECG pattern and a history of syncope and malignant ventricular arrhythmias. Patients without demonstrable structural heart disease and an ECG pattern of RBBB and ST segment elevation in leads V1 through V3 are at risk for sudden cardiac death. They demonstrate the role of cardiac electrophysiology study including programmed ventricular stimulation and pharmacological testing in evaluation of patients with possible Brugada syndrome. The authors emphasize the role of implantable cardioverter defibrillator (ICD) therapy in treatment of patients with Brugada syndrome.
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PMID:[Right bundle branch block and ST-segment elevation in right precordial leads: a marker for sudden cardiac death]. 1076 45

Recent advances of nonpharmacological therapy such as catheter ablation and implantable cardioverter defibrillator and lessons from the Cardiac Arrhythmia Suppression Trial(CAST) have changed the strategy for ventricular arrhythmias. The safety and efficacy of radiofrequency catheter ablation of symptomatic sustained monomorphic ventricular tachycardia without structural heart disease has made ablation the firstline curative therapy. In idiopathic ventricular fibrillation such as Brugada syndrome, an implantable cardioverter defibrillator is the most effective treatment to prevent sudden cardiac death. In patients with asymptomatic ventricular tachyarrhythmias in heart failure, class I antiarrhythmic drugs should be avoided due to proarrhythmic and negative inotropic effects that may be responsible for increased mortality in some trials. In such patients, amiodarone and beta-blocker may reduce sudden cardiac death. For patients with sustained ventricular tachycardia or ventricular fibrillation in heart failure, amiodarone or implantable cardioverter defibrillator should be considered. In comparison with amiodarone, implantable cardioverter defibrillator markedly reduced sudden death in ventricular tachycardia and ventricular fibrillation survivors in Antiarrhythmics Versus Implantable Defibriltors(AVID). Although better patient selection and clarification of mapping criteria improved the successful ablation rate in patients with structural heart disease, candidates of ablation are few. In patients with extensive structural heart disease, multiple ventricular tachycardias are often present. Catheter ablation of a single ventricular tachycardia may be only palliative. Therefore, implantable cardioverter defibrillator is the most effective treatment to prevent sudden cardiac death, with amiodarone and ablation as the adjunctive therapy to prevent frequent ventricular tachycardia. Furthermore, an implantable cardioverter defibrillator improved survival in selected patients with depressed ventricular function after myocardial infarction, who also have nonsustained and inducible sustained ventricular tachycardia in Multicenter Automatic Defibrillator Implantation Trial(MADIT) and Multicenter Unsustained Tachycardia Trial(MUSTT).
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PMID:[Long-term outcome of pharmacological and nonpharmacological treatment for ventricular arrhythmias]. 1083 74

About 10-20% of patients dying suddenly or resuscitated from ventricular fibrillation do not have demonstrable heart disease. These people are often young and tragically in some cases sudden death is the first and only clinical event. One of the three main electrophysiological diagnoses to be considered in these situations is the Brugada syndrome. A case of Brugada syndrome is described, together with an example of the classic electrocardiographic manifestations and a discussion of the possible aetiology, diagnosis and management of this condition.
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PMID:Brugada syndrome--the missed epidemic. 1110 50

Life-threatening ventricular arrhythmias in the athlete nearly always occur in the presence of structural heart disease. In the last few years, 2 new causes of life-threatening arrhythmias have been described in patients with normal hearts-that of the Brugada syndrome and that of commotio cordis. Non-life-threatening premature ventricular beats and even nonsustained ventricular tachycardia are not rare, and although usually benign, can be secondary to cardiomyopathies. Athletes with symptoms of syncope, especially if exertional, warrant a complete evaluation. The treatment of athletes and other individuals with life-threatening ventricular arrhythmias has been revolutionized by the implantable cardioverter defibrillator, a device that affords excellent protection from sudden death. Defining those athletes who would benefit from the implantable defibrillator is not always clear. Furthermore, participation in competitive athletics for athletes with life-threatening arrhythmias or structural heart disease known to put the athlete at risk for life-threatening arrhythmias is usually prohibited.
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PMID:Ventricular arrhythmias in the athlete. 1112 16

We describe a 45-year-old Taiwanese man with specific features of Brugada syndrome but no clinical features of structural heart disease. He was successfully treated with an implantable cardioverter-defibrillator. His electrocardiogram (ECG) patterns changed intermittently. Alpha-adrenoceptor stimulation and beta-adrenoceptor blockade augmented the characteristic ST-segment elevation, whereas alpha-adrenoceptor blockade and beta-adrenoceptor stimulation mitigated the ST-segment elevation. Intravenous procainamide administration did not aggravate ST-segment elevation when ECG had shown coved ST elevation in the right precordial leads. Molecular study did not reveal the same mutations in the cardiac sodium channel gene (SCN5A) as previously reported in Brugada syndrome. This case demonstrates the genetic heterogeneity of SCN5A in Brugada syndrome.
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PMID:Brugada syndrome without mutation of the cardiac sodium channel gene in a Taiwanese patient. 1115 78

A 56-year-old woman without structural heart disease had an ECG typical of Brugada syndrome. Syncope occurred due to monomorphic VT with left bundle branch block (LBBB) morphology. At electrophysiological study, VT with the same morphology was inducible.
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PMID:Brugada syndrome: a case report of monomorphic ventricular tachycardia. 1122 55

The Brugada syndrome is an arrhythmic syndrome characterized by a right bundle branch block pattern and ST segment elevation in the right precordial leads of the electrocardiogram in conjunction with a high incidence of sudden death secondary to ventricular tachyarrhythmias. No evidence of structural heart disease is noted during diagnostic evaluation of these patients. In 25% of families, there appears to be an autosomal dominant mode of transmission with variable expression of the abnormal gene. Mutations have been identified in the gene that encodes the alpha subunit of the sodium channel (SCN5A) on chromosome 3. This genetic defect causes a reduction in the density of the sodium current and explains the worsening of the above electrocardiographic abnormalities when patients are treated with sodium channel blocking antiarrhythmic agents, which further diminish the already reduced sodium current. The prognosis is poor with up to a 10% per year mortality. Antiarrhythmic drugs including beta-blockers and amiodarone have no benefit in prolonging survival. The treatment of choice is the insertion of an implantable cardioverter-defibrillator.
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PMID:The Brugada syndrome: clinical, genetic, cellular, and molecular abnormalities. 1134 71

Advances in the treatment and prevention of heart disease have led to consistently declining morbidity and mortality rates over the past 30 years. Despite these advances, therapy remains largely palliative. The development of curative therapies is limited by our lack of knowledge of the basic mechanisms of disease. In the next decade, we will probably change many of these current approaches from treating the crisis to preventing the disease. Molecular biology and genetics have elucidated several basic pathways. It is hoped that targeted therapies will prevent or arrest many of these cardiac diseases, in particular, arrhythmias and sudden death. With the discovery of the genes causing familial diseases like long QT, hypertrophic cardiomyopathy, and Brugada syndrome, we have identified several substrates responsible for triggering malignant arrhythmias.
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PMID:Genetic aspects of arrhythmias. 1137 43


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