다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Since its introduction as a clinical entity in 1992, the Brugada syndrome has progressed from being a rare disease to one that is second only to automobile accidents as a cause of death among young adults in some countries Electrocardiographically characterized by a distinct ST-segment elevation in the right precordial leads, the syndrome is associated with a high risk for sudden cardiac death in young and otherwise healthy adults, and less frequently in infants and children Patients with a spontaneously appearing Brugada ECG have a high risk for sudden arrhythmic death secondary to ventricular tachycardia/fibrillation The ECG manifestations of Brugada syndrome are often dynamic or concealed and may be unmasked or modulated by sodium channel blockers, a febrile state, vagotonic agents, α-adrenergic agonists, β-adrenergic blockers, tricyclic or tetracyclic antidepressants, a combination of glucose and insulin, hypo- and hyperkalemia, hypercalcemia, and alcohol and cocaine toxicity In recent years, an exponential rise in the number of reported cases and a striking proliferation of articles defining the clinical, genetic, cellular, ionic, and molecular aspects of the disease have occurred The report of the first consensus conference, published in 2002, focused on diagnostic criteria The present report, which emanated from the second consensus conference held in September 2003, elaborates further on the diagnostic criteria and examines risk stratification schemes and device and pharmacological approaches to therapy on the basis of the available clinical and basic science data

Brugada Syndrome: Report of the Second Consensus Conference Endorsed by the Heart Rhythm Society and the European Heart Rhythm Association

Ventricular fibrillation causes more than 300,000 sudden deaths each year in the USA alone. In approximately 5-12% of these cases, there are no demonstrable cardiac or non-cardiac causes to account for the episode, which is therefore classified as idiopathic ventricular fibrillation (IVF). A distinct group of IVF patients has been found to present with a characteristic electrocardiographic pattern. Because of the small size of most pedigrees and the high incidence of sudden death, however, molecular genetic studies of IVF have not yet been done. Because IVF causes cardiac rhythm disturbance, we investigated whether malfunction of ion channels could cause the disorder by studying mutations in the cardiac sodium channel gene SCN5A. We have now identified a missense mutation, a splice-donor mutation, and a frameshift mutation in the coding region of SCN5A in three IVF families. We show that sodium channels with the missense mutation recover from inactivation more rapidly than normal and that the frameshift mutation causes the sodium channel to be non-functional. Our results indicate that mutations in cardiac ion-channel genes contribute to the risk of developing IVF.

Genetic basis and molecular mechanism for idiopathic ventricular fibrillation

The single most common cause of the withdrawal or restriction of the use of marketed drugs has been QT-interval prolongation associated with polymorphic ventricular tachycardia, or torsade de pointes, a condition that can be fatal. This review summarizes the current knowledge about molecular and clinical predictors of drug-induced QT-interval prolongation and torsade de pointes and discusses how new molecular predictors of drug action might be incorporated into drug-development programs and clinical practice. A general approach to drugs suspected of causing this problem is presented.

/pdf/drug-induced-prolongation-of-the-qt-interval-4t6t033bam.pdf

Drug-induced prolongation of the QT interval.

HRS/EHRA/APHRS expert consensus statement on the diagnosis and management of patients with inherited primary arrhythmia syndromes: document endorsed by HRS, EHRA, and APHRS in May 2013 and by ACCF, AHA, PACES, and AEPC in June 2013.

Background: The Brugada Electrocardiographic Indices Registry is a comprehensive data registry composed of patients with Brugada patterns on the electrocardiogram (ECG). The aim is to test the hypotheses that (i) ECG indices combining both depolarization and repolarization abnormalities
 can better predict spontaneous ventricular arrhythmias than existing ECG markers in Brugada syndrome and (ii) that serial ECG measurements will provide additional information for risk stratification, especially in asymptomatic patients.Methods: Patients with both Brugada pattern
 ECGs and Brugada syndrome are eligible for inclusion in this registry. Baseline characteristics and ECG variables reflecting depolarization and repolarization will be determined. The primary outcome is spontaneous ventricular tachycardia/ventricular fibrillation or sudden cardiac death. Secondary
 outcomes are inducible ventricular tachycardia/ventricular fibrillation and syncope.Results: As of November 15, 2019, 39 investigators from 32 cities in 18 countries had joined this registry. As of December 15, 2019, 1383 cases had been enrolled.Conclusions: The Brugada
 Electrocardiographic Indices Registry will evaluate the disease life course, risk factors, and prognosis in a large series of Brugada patients. It will therefore provide insights for improving risk stratification.

An Open Invitation to Join the International Brugada Electrocardiographic Indices Registry

https://www.heartrhythmjournal.com/article/S1547-5271(11)00274-8/pdf

Instability of type 1 Brugada wave: A more sensitive ECG predictor of cardiac events?

Short QT Syndrome is a recently recognized inherited channelopathy responsible for sudden cardiac death (SCD) in individuals with a structurally normal heart. It is characterized by abnormally short QTc interval (<360 msec) on the electrocardiogram seen in conjunction with a family history of atrial and/or ventricular fibrillation. It is a genetically heterogeneous disease with mutations in five different genes encoding cardiac ion channels linked to familial or sporadic cases. Based on the chronology of discovery, gain-of-function mutations in KCNH2, KCNQ1, and KCNJ2 have been labeled SQT1, SQT2 and SQT3, respectively. In addition, loss-of-function mutations in two calcium channel genes CACNA1C and CACNB2B have been linked to a new clinical entity characterized by a SQTS and Brugada syndrome phenotype. These have been designated as SQT4 and SQT5, respectively. SCD is a common presenting symptom and has been reported as early as the first year of life, suggesting that SQTS may be responsible for some cases of sudden infant death. Amplified transmural dispersion of repolarization along with abbreviation of the refractory period is thought to underlie the cellular basis for arrhythmogenesis in SQTS. Implantation of an implantable cardioverter defibrillator is recommended for both primary and secondary prevention of SCD. Data regarding a pharmacologic approach to therapy are limited, but quinidine has been identified as being of benefit. This chapter provides an overview of the available literature.

Short QT Syndrome: Clinical Presentation, Molecular, Genetic, Cellular, and Ionic Basis

See article by Frey et al. [8] (pages 254–264) in this issue. 

Hypertrophic cardiomyopathy is a terrible disease [1]. It is associated with negative hemodynamic changes leading to pulmonary congestion and low output, and with severe ventricular arrhythmias that in many cases are lethal. We have learned a good deal about the electrophysiology of this disease [2]. Unlike ischemic heart disease that predisposes to conduction block and reentrant arrhythmias on that basis, the lesion of hypertrophy involves repolarization [3]. Hypertrophied cells have long and non-uniform repolarization times. This dispersion of action potential duration is a milieu in which early afterdepolarizations can generate sustained and highly disorganized ventricular arrhythmias, manifest on the surface ECG as polymorphous ventricular tachycardia that quickly degenerates into ventricular fibrillation. As hypertrophy progresses, the situation is further complicated by fibrosis and irregular cell connection that increases the potential for transmyocardial reentry and arrhythmogenesis. Hypertrophied cells, already manifesting marked potassium channel abnormalities, are highly sensitive to metabolic conditions such as hypokalemia, or QT prolonging drugs that further prolong refractoriness, compounding the potential for polymorphic ventricular tachycardia [3,4]. Thus, in patients with hypertrophic disease, in particular the familial form, sudden and unexpected death is a heavy liability.

Unfortunately, we have not yet developed efficient methods to predict which patients are uniquely susceptible to this problem, nor have we available highly effective or safe …

Gan-Xin Yan

Papers

An Open Invitation to Join the International Brugada Electrocardiographic Indices Registry

Instability of type 1 Brugada wave: A more sensitive ECG predictor of cardiac events?

Short QT Syndrome: Clinical Presentation, Molecular, Genetic, Cellular, and Ionic Basis

Familial hypertrophic cardiomyopathy: cornering the rat

Mexiletine: a treatment for all cause acquired qt interval prolongation