Incidence of Atrial Tachyarrhythmias in Patients With Early Repolarization Syndrome

Abstract

SummaryAtrial tachyarrhythmias (ATAs) occur in a significant proportion of Brugada syndrome (BrS) patients and are often an important cause of inappropriate shocks. The aim of this retrospective study was to evaluate the incidence of ATAs and ATA-induced inappropriate shocks in early repolarization syndrome (ERS) patients as compared to BrS patients.We analyzed data from 20 consecutive patients who were diagnosed with ERS and compared them with patients diagnosed with BrS (n = 31). Clinical and ICD interrogation data were collected and analyzed for all events with ICD shocks.Three patients had a history of atrial fibrillation (AF) prior to ICD implantation. One patient had AV reentrant tachycardia and was successfully ablated before ICD implantation. ATAs were newly diagnosed in 4 patients with no prior history of AF. There were no significant differences in gender, age, or left atrial diameter between ATA development. Four (20%) of 20 consecutive patients received inappropriate ICD shocks for ATAs. One suffered from repeat inappropriate shocks triggered by paroxysmal AF and received catheter ablation for AF.ATAs were not infrequent in patients with ERS and seemed to be related to inappropriate ICD therapy. Careful ICD programming is required to reduce ATA-related inappropriate ICD shock in patients with ERS. (Int Heart J 2017; 58: 43-49) Key words: Early repolarization syndrome, Brugada syndrome, Sudden cardiac death E arly repolarization syndrome (ERS) has recently been uncovered as an important cause of sudden cardiac death (SCD) or life-threatening arrhythmias in patients with structurally normal hearts.1-3) Several basic studies reported that transmural or epicardial dispersion of action potentials in the early repolarization phase is responsible for the electrocardiographic phenotype of the ST segment and J wave elevation, suggesting a common electrophysiologic background between Brugada syndrome (BrS) and ERS. 4,5) A significant proportion of patients with BrS develop atrial tachyarrhythmias (ATAs), which are often an important cause of inappropriate shock. [6][7][8][9] There are many similarities between BrS and ERS in clinical and electrocardiographic characteristics.5) As the dysfunction of cardiac ion channels is not limited to the ventricular myocardium, it may be possible that electrical abnormalities coexist in the atrial and ventricular myocardium of patients with ERS. Gain or loss-of-function mutations in atrial ion channels may lead to shortening or prolongation of atrial action potential durations, resulting in increased dispersion of atrial repolarization or intra-atrial conduction time in patients with ERS. The aim of this retrospective study was to evaluate the incidence of ATAs and ATAinduced inappropriate shock in patients with ERS as compared to those with BrS.

Clinical and Functional Genetic Characterization of the Role of Cardiac Calcium Channel Variants in the Early Repolarization Syndrome

“…Besides, we found three patients (18.8%) present with AF, a higher prevalence than in the general population. Watanabe et al reported that AF is found in 23% of their cases with ERS, and AF has been reported in 15% of ERS patients in the investigation of Hwang et al and 22% in the research of Kamakura et al, implying high overlapping between AF and ERS (29)(30)(31). A report also demonstrates that ERP is more common in patients younger than 60 years with lone AF than healthy controls and declares that ERP may indicate susceptibility to AF (32).…”

A Slower Heart Rate and Therapeutic Hypothermia Unmasked Early Repolarization Syndrome in a Ventricular Fibrillation Survivor

“…Several ERS cases who survived from an aborted death or VF have been reported. 15) However, to the best of our knowledge, there have been no reports in which the detailed and serial changes in the J-wave amplitude and morphology during therapeutic hypothermia and occurrences of VF were recorded. Therapeutic hypothermia can lead to VF due to an exacerbation of J-waves.…”

Evaluation of atrial electromechanical delay and left atrial phasic function in individuals with electrocardiographic early repolarization pattern

“…It has been reported that several genetic mutations detected in individuals with ERP may also be associated with AF (21,22). These mutations expressed in both atria and ventricles may cause increased susceptibility to AF in addition to the phenotypic expression of ERP (23). Another example for the relationship between ERP and AF is the athlete's heart.…”