Inherited arrhythmia syndrome predisposing to sudden cardiac death

Abstract

Inherited arrhythmia (IA) is one of the main causes of sudden cardiac death (SCD) in young people, and is reported to be more prevalent as a cause of SCD in Asia compared to western countries. IA is a group of genetic disorders caused by mutations in gene encoding cardiac ion channels, leading to electrophysiological characteristics that often occur in the absence of structural abnormalities. Channelopathies, such as long QT syndrome (LQTS) and Brugada syndrome (BrS), have a potential risk of life threatening ventricular tachyarrhythmias that predispose into SCD, although early prediction and prevention for the risk remains challenging. Recent advances in genetic testing enable physicians to facilitate risk stratification as well as precise diagnosis for IA despite of ongoing debates for the implications. Herein, we will provide an epidemiological data, a pathophysiological overview, and the current clinical approach focusing on IAs related to SCD. In addition, we will review the general issues arising from genetic testing for IAs.

Impact of Dietary Factors on Brugada Syndrome and Long QT Syndrome

“…LQTS is usually diagnosed by measuring the QT interval on the ECG and it can include adrenalin and isoproterenol test. Moreover, epinephrine test is able to unmask the prolongation of the QT intervals in patients with ‘concealed LQTS’ [ 15 ]. The ECG may result normal at rest but based on the subtype, ECG abnormalities can be triggered by physical stress, emotional stress, dietary changes, certain drugs, or during sleep or at rest [ 16 , 17 ], and it has also been associated with metabolic syndromes and eating disorders [ 13 ].…”

Metabolic Syndrome, Gamma-Glutamyl Transferase, and Risk of Sudden Cardiac Death

“…The underlying causes of SCD include coronary artery disease, primary myocardial or electrical disorders such as hypertrophic cardiomyopathy and Brugada syndrome, and valvular heart disease [ 3 , 8 ]. Metabolic syndrome, which is characterized by abdominal obesity, dyslipidemia, an elevated fasting glucose, and high blood pressure, is an established risk factor for coronary artery disease and SCD [ 9 , 10 ].…”

European Heart Rhythm Association (EHRA)/Heart Rhythm Society (HRS)/Asia Pacific Heart Rhythm Society (APHRS)/Latin American Heart Rhythm Society (LAHRS) Expert Consensus Statement on the state of genetic testing for cardiac diseases

“…173 Symptomatic patients are typically males presenting in their fourth decade of life. 174,175 Brugada syndrome may be involved in ∼18-28% of unexplained sudden deaths/arrests. 176,177 According to the 2013 HRS/EHRA/APHRS expert consensus statement, 15 BrS is diagnosed in patients with ST-segment elevation with type I morphology ≥2 mm in ≥1 lead among the right precordial leads V1, V2 positioned in the 4th intercostal space (standard ECG)…”

“…The prevalence of BrS is estimated to be 1 in 2000 worldwide, with higher prevalence in Asia 173 . Symptomatic patients are typically males presenting in their fourth decade of life 174,175 . Brugada syndrome may be involved in ∼18–28% of unexplained sudden deaths/arrests 176,177 …”