Clinical frontiers in electrocardiographic early repolarization syndrome： does a good guy turn bad now？

Early repolarization pattern （ERP） is a common electrocardiographic （ECG） variant, characterized by J point elevation manifested either as QRS slurring （at the transition from the QRS segment to the ST segment） or notching （a positive deflection inscribed on terminal S wave）, ST-segment elevation with upper concavity and prominent T waves in at least two contiguous leads, The prevalence of ERP in normal population varies from 1% to 13%, depending on the age （predominant in young adults）, the race （highest amongst black oooulation）,

Heart rate profile during exercise in patients with early repolarization

Background Both early repolarization and altered heart rate profile are associated with sudden death. In this study, we aimed to demonstrate an association between early repolarization and heart rate profile during exercise.Methods A total of 84 subjects were included in the study. Comparable 44 subjects with early repolarization and 40 subjects with normal electrocardiogram underwent exercise stress testing. Resting heart rate, maximum heart rate, heart rate increment and decrement were analyzed.Results Both groups were comparable for baseline characteristics including resting heart rate. Maximum heart rate, heart rate increment and heart rate decrment of the subjects in early repolarization group had significantly decreased maximum heart rate, heart rate increment and heart rate decrement compared to control group （all P〈0.05）. The lower heart rate increment （〈106 beats/min） and heart rate decrement （〈95 beats/min） were significantly associated with the presence of early repolarization. After adjustment for age and sex, the multiple-adjusted OR of the risk of presence of early repolarization was 2.98 （95% CI 1.21-7.34） （P=0.018） and 7.73 （95% CI 2.84-21.03） （P 〈0.001） for the lower heart rate increment and heart rate decrement compared to higher levels, respectively.Conclusions Subjects with early repolarization have altered heart rate profile during exercise compared to control subjects. This can be related to sudden death.

J Wave Syndromes： A Decade of Progress

Objective： The objective was to provide a brief history of J wave molecular, ionic, cellular mechanisms, and clinical features. We will clinical research for J wave syndromes. syndromes and to summarize our current understanding of their also discuss the existing debates and further direction in basic and Data Sources： The publications on key words of＂J wave syndromes＂, ＂early repolarization syndrome （ERS）＂, ＂Brugada syndrome （BrS）＂ and ＂ST-segment elevation myocardial infarction （STEMI）＂ were comprehensively reviewed through search of the PubMed literatures without restriction on the publication date. Study Selection： Original articles, reviews and other literatures concerning J wave syndromes, ERS, BrS and STEMI were selected. Results： J wave syndromes were firstly defined by Yah et al. in a Chinese journal a decade ago, which represent a spectrum of variable phenotypes characterized by appearance of prominent electrocardiographic J wave including ERS, BrS and ventricular fibrillation （VF） associated with hypothermia and acute STEMI. J wave syndromes can be inherited or acquired and are mechanistically linked to amplification of the transient outward current （I ）-mediated J waves that can lead to phase 2 reentry capable of initiating VF. Conclusions： J wave syndromes are a group of newly highlighted clinical entities that share similar molecular, ionic and cellular mechanism and marked by amplified J wave on the electrocardiogram and a risk of VF. The clinical challenge ahead is to identify the patients with J wave syndromes who are at risk for sudden cardiac death and determine the alternative therapeutic strategies to reduce mortality.