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BACKGROUND: Few small-sample studies have quantified the T-wave alternans (TWA) value by 24-hour ambulatory recordings or exercise stress tests in patients with long QT syndrome (LQTS). The cutoff point of TWA ≥47 µV was based on patients with myocardial infarction. In our study, we aimed to (1) evaluate the association of TWA with life-threatening arrhythmic events (LAEs); (2) compare the predictive model of LAEs according to the TWA value measured by 24-hour ambulatory recordings and exercise stress tests; and (3) propose a cutoff point for the high risk of LAEs in patients with LQTS. METHODS AND RESULTS: The study cohort included 110 patients with LQTS referred to our hospital, and the primary outcome was LAEs. Thirty-one patients with LQTS (31/110 [28.2%]) developed LAEs during the following 24 (12-47) months. Peak TWA value quantified from 12 leads by 24-hour ambulatory recordings in patients with LQTS with LAEs (LQTS-LAEs group) was significantly higher than LQTS without LAEs (LQTS-non-LAEs group) (64.0 [42.0-86.0] µV versus 43.0 [36.0-53.0] µV; P<0.01). There was no statistical difference in TWA value measured by exercise stress tests between the 2 groups (69.0 [54.5-127.5] µV versus 68.5 [53.3-99.8] µV; P=0.871). The new cutoff point of the peak TWA value measured by 24-hour ambulatory recordings was 55.5 µV, with a sensitivity of 75.0% and a specificity of 78.6%. A univariate Cox regression analysis revealed that TWA value ≥55.5 µV was a strong predictor of LAEs (hazard ratio [HR], 4.5 [2.1-9.6]; P<0.001]. A multivariate Cox regression analysis indicated that TWA value ≥55.5 µV remained significant (HR, 2.7 [1.1-6.8]; P=0.034). CONCLUSIONS: Peak TWA measured by 24-hour ambulatory recordings was a more favorable risk stratification marker than exercise stress tests for patients with LQTS.
Assuntos
Eletrocardiografia Ambulatorial , Teste de Esforço , Síndrome do QT Longo , Humanos , Feminino , Síndrome do QT Longo/diagnóstico , Síndrome do QT Longo/fisiopatologia , Masculino , Teste de Esforço/métodos , Medição de Risco/métodos , Adulto , Eletrocardiografia Ambulatorial/métodos , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Fatores de Risco , Adulto Jovem , Prognóstico , Fatores de Tempo , Estudos Retrospectivos , Frequência Cardíaca/fisiologiaRESUMO
Background: Arrhythmogenic cardiomyopathy/dysplasia (ACM) is an inheritable heart disease closely related to gene variations induced heart fibrofatty replacement, which increases the risk of arrhythmia events and even sudden cardiac death. In this study, we reported a 10-year-old patient with a novel mutation diagnosed with ACM. Case presentation: We present the case of a 10-year-old patient admitted with recurrent palpitation, whose electrocardiogram suggested the existence of right ventricle origin premature ventricular contractions and ε wave. Furthermore, echocardiography showed an enlarged right ventricle corrected to a body surface area of 29.57â mm/m2. The diagnosis of ACM was clear. Further gene sequencing revealed a novel heterozygous missense mutation of CDH2 (cadherin-2) c.547C > G (p. P183A) that potentially increases ACM risk by affecting adherens junctions of the intercalated discs. Conclusions: This is the first case of CDH2 mutation (c.547C > G, p. P183A) related ACM in the Chinese population. Compared to previously reported mutations inducing ACM by affecting desmosome function, the newly reported CDH2 variation revealed a novel potential mechanism that induces ACM by disturbing cell-cell adhesion.
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Drawing on Wigfield and Eccles's motivational theory, which is acclaimed for explaining individual behavioral intentions, this study investigated the extent to which different forms of motivation (i.e., self-efficacy, task value, and intrinsic and extrinsic motivations) predicted student behavioral feedback engagement (i.e., action on teacher feedback and feedback seeking) in English learning. The participants were 276 male and female students who were enrolled in a second-year full-time English language and literature program at two Chinese universities. Multiple regression analyses showed that task value emerged as the only motivational variable that significantly predicted both students' action on teacher feedback and feedback seeking. Intrinsic motivation significantly predicted action on teacher feedback, whereas extrinsic motivation and self-efficacy significantly predicted feedback seeking. Pedagogical implications for endeavors to support students in their engagement with feedback in learning English as a foreign language in China are discussed.
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Studies show that parental educational expectations (PEEs) serve as an intermediary variable between family background and children's educational attainment. This paper re-examines the relationship between PEEs and children's higher educational attainment using data from the China Family Panel Studies (CFPS) 2010-2018. To address potential endogenous problems in the previous papers, we use the average College Enrolment Opportunity Index (CEOI) when the children were 10-12 years old as an instrumental variable for PEEs. The results revealed that: (1) In addition to the indirect intermediary effects, the PEEs also had a direct impact on children's higher educational attainment independent of family background; (2) the magnitude of the effect was much larger (almost three times) than previous estimates after solving endogenous problems; (3) there was no significant gender difference in the effect of PEEs. In addition, we also found that PEEs had a greater impact on middle- and low-income families. Therefore, we argue that against the background of the "Double Reduction" policy, parents should change their conception of education and raise their expectations for their children and encourage them to strive for higher educational achievements.
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In spite of much recent theorizing about teacher provision of feedback, relatively fewer studies look at the dynamic relationships between teacher feedback practices, student feedback experience, and their learning outcomes in higher education settings. To fill this gap, this study looked at 308 university students' perceived teacher feedback practices and their feedback experiences in an English Studies course context at a key and non-key university, and explored how teacher feedback, student feedback motivation and feedback behavior were associated with students' course satisfaction and course exam performance. Results showed that students from the key university reported a higher level of teacher feedback use as well as student feedback motivation and behavior. Structural equation modeling (SEM) suggested that in the case of the non-key university, student feedback behavior significantly predicted course satisfaction and course exam results; teacher feedback also indirectly influenced course satisfaction and course exam results. In the case of the key university, while teacher feedback and student feedback behavior each had significant influence on course satisfaction, student feedback behavior showed no direct significant effect on course exam results, and teacher feedback also showed no significant indirect influence on course exam results.