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Early repolarization syndrome (ERS) is defined as occurring in patients with early repolarization pattern who have survived idiopathic ventricular fibrillation with clinical evaluation unrevealing for other explanations. The pathophysiologic basis of the ERS is currently uncertain. The objective of the present study was to examine the electrophysiological mechanism of ERS utilizing induced pluripotent stem cells (iPSCs) and CRISPR/Cas9 genome editing. Whole genome sequencing was used to identify the DPP6 (c.2561T > C/p.L854P) variant in four families with sudden cardiac arrest induced by ERS. Cardiomyocytes were generated from iPSCs from a 14-year-old boy in the four families with ERS and an unrelated healthy control subject. Patch clamp recordings revealed more significant prolongation of the action potential duration (APD) and increased transient outward potassium current (Ito) (103.97 ± 18.73 pA/pF vs 44.36 ± 16.54 pA/pF at +70 mV, P < 0.05) in ERS cardiomyocytes compared with control cardiomyocytes. Of note, the selective correction of the causal variant in iPSC-derived cardiomyocytes using CRISPR/Cas9 gene editing normalized the Ito, whereas prolongation of the APD remained unchanged. ERS cardiomyocytes carrying DPP6 mutation increased Ito and lengthen APD, which maybe lay the electrophysiological foundation of ERS.
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BACKGROUND: Atrial fibrillation (AF) is a prevalent arrhythmic condition resulting in increased stroke risk and is associated with high mortality. Electrolyte imbalance can increase the risk of AF, where the relationship between AF and serum electrolytes remains unclear. METHODS: A total of 15,792 individuals were included in the observational study, with incident AF ascertainment in the Atherosclerosis Risk in Communities (ARIC) study. The Cox regression models were applied to calculate the hazard ratio (HR) and 95% confidence interval (CI) for AF based on different serum electrolyte levels. Mendelian randomization (MR) analyses were performed to examine the causal association. RESULTS: In observational study, after a median 19.7 years of follow-up, a total of 2551 developed AF. After full adjustment, participants with serum potassium below the 5th percentile had a higher risk of AF relative to participants in the middle quintile. Serum magnesium was also inversely associated with the risk of AF. An increased incidence of AF was identified in individuals with higher serum phosphate percentiles. Serum calcium levels were not related to AF risk. Moreover, MR analysis indicated that genetically predicted serum electrolyte levels were not causally associated with AF risk. The odds ratio for AF were 0.999 for potassium, 1.044 for magnesium, 0.728 for phosphate, and 0.979 for calcium, respectively. CONCLUSIONS: Serum electrolyte disorders such as hypokalemia, hypomagnesemia and hyperphosphatemia were associated with an increased risk of AF and may also serve to be prognostic factors. However, the present study did not support serum electrolytes as causal mediators for AF development.
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Fibrilação Atrial , Humanos , Fibrilação Atrial/epidemiologia , Fibrilação Atrial/genética , Fatores de Risco , Magnésio , Análise da Randomização Mendeliana , Cálcio , Potássio , Fosfatos , Eletrólitos , Estudo de Associação Genômica Ampla/métodosRESUMO
BACKGROUND: Mutations in human ether-à-go-go-related gene (hERG) potassium channels are closely associated with long QT syndrome (LQTS). Previous studies have demonstrated that macrolide antibiotics increase the risk of cardiovascular diseases. To date, the mechanisms underlying acquired LQTS remain elusive. METHODS: A novel hERG mutation I1025N was identified in an azithromycin-treated patient with acquired long QT syndrome via Sanger sequencing. The mutant I1025N plasmid was transfected into HEK-293 cells, which were subsequently incubated with azithromycin. The effect of azithromycin and mutant I1025N on the hERG channel was evaluated via western blot, immunofluorescence, and electrophysiology techniques. RESULTS: The protein expression of the mature hERG protein was down-regulated, whereas that of the immature hERG protein was up-regulated in mutant I1025N HEK-293 cells. Azithromycin administration resulted in a negative effect on the maturation of the hERG protein. Additionally, the I1025N mutation exerted an inhibitory effect on hERG channel current. Moreover, azithromycin inhibited hERG channel current in a concentration-dependent manner. The I1025N mutation and azithromycin synergistically decreased hERG channel expression and hERG current. However, the I1025N mutation and azithromycin did not alter channel gating dynamics. CONCLUSIONS: These findings suggest that hERG gene mutations might be involved in the genetic susceptibility mechanism underlying acquired LQTS induced by azithromycin.
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Azitromicina , Síndrome do QT Longo , Humanos , Azitromicina/efeitos adversos , Células HEK293 , Antibacterianos/efeitos adversos , Síndrome do QT Longo/induzido quimicamente , Síndrome do QT Longo/genética , MutaçãoRESUMO
Introduction: Chronic total occlusion (CTO) of coronary arteries constitutes a substantial clinical challenge and has historically been managed through medical management and coronary artery bypass grafting (CABG). However, with the advancement in interventional technology, the success rate of percutaneous treatment has been significantly improved, and percutaneous coronary intervention (PCI) has emerged as a primary mode of treatment for CTOs, demonstrating remarkable clinical efficacy. The objective of this systematic review and meta-analysis is to evaluate and contrast the outcomes of PCI and CABG in patients with CTO. Methods and Results: A systematic search was conducted in the databases of PubMed, Embase, and Web of Science. The primary endpoints evaluated in this meta-analysis were the occurrence of major adverse cardiac events (MACE) and all-cause mortality. Secondary endpoints included myocardial infarction (MI), cardiac death, and the need for repeat revascularization. Nine studies, encompassing a total of 8,674 patients, were found to meet the criteria for inclusion and had a mean follow-up duration of 4.3 years. The results of the meta-analysis revealed that compared to CABG, PCI was associated with a lower incidence of all-cause mortality (RR: 0.78, 95% CI: 0.66-0.92; P = 0.003) and cardiac death (RR: 0.55; 95% CI: 0.31-0.96; P < 0.05), but an increased risk of myocardial infarction (MI) (RR: 1.96; 95%CI: 1.07-3.62; P < 0.05) and repeat revascularization (RR: 7.13; 95% CI: 5.69-8.94; P < 0.00001). There was no statistically significant difference in MACE (RR: 1.11; 95% CI: 0.69-1.81; P = 0.66) between the PCI and CABG groups. Conclusion: In the present meta-analysis comparing PCI and CABG in patients with chronic total occlusion of the coronary arteries, the results indicated that PCI was superior to CABG in reducing all-cause mortality and cardiac death but inferior in decreasing myocardial infarction and repeat revascularization. There was no statistically significant difference in MACE between the two groups.
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Doença da Artéria Coronariana , Oclusão Coronária , Infarto do Miocárdio , Intervenção Coronária Percutânea , Humanos , Vasos Coronários/cirurgia , Intervenção Coronária Percutânea/efeitos adversos , Ponte de Artéria Coronária/efeitos adversos , Resultado do Tratamento , Morte , Doença da Artéria Coronariana/cirurgia , Doença da Artéria Coronariana/complicações , Fatores de Risco , Oclusão Coronária/terapiaRESUMO
BACKGROUND: Growing evidence suggests that compromised lung health may be linked to cardiovascular disease. However, little is known about its association with sudden cardiac death (SCD). OBJECTIVES: We aimed to assess the link between impaired lung function, airflow obstruction and risk of SCD by race and gender in four US communities. METHODS: A total of 14 708 Atherosclerosis Risk in Communities (ARIC) study participants who underwent spirometry and were asked about lung health (1987-1989) were followed. The main outcome was physician-adjudicated SCD. Fine-Gray proportional subdistribution hazard models with Firth's penalised partial likelihood correction were used to estimate the HRs. RESULTS: Over a median follow-up of 25.4 years, 706 (4.8%) subjects experienced SCD. The incidence of SCD was inversely associated with FEV1 in each of the four race and gender groups and across all smoking status categories. After adjusting for multiple measured confounders, HRs of SCD comparing the lowest with the highest quintile of FEV1 were 2.62 (95% CI 1.62 to 4.26) for white males, 1.80 (95% CI 1.03 to 3.15) for white females, 2.07 (95% CI 1.05 to 4.11) for black males and 2.62 (95% CI 1.21 to 5.65) for black females. The above associations were consistently observed among the never smokers. Moderate to very severe airflow obstruction was associated with increased risk of SCD. Addition of FEV1 significantly improved the predictive power for SCD. CONCLUSIONS: Impaired lung function and airflow obstruction were associated with increased risk of SCD in general population. Additional research to elucidate the underlying mechanisms is warranted.
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Pneumopatias , Doença Pulmonar Obstrutiva Crônica , Morte Súbita Cardíaca/epidemiologia , Morte Súbita Cardíaca/etiologia , Feminino , Humanos , Pulmão , Masculino , Estudos Prospectivos , Fatores de RiscoRESUMO
BACKGROUND: Several studies have demonstrated that cardiovascular risk factors play a role in the etiology of breast cancer. However, the combined effect of cardiovascular risk factors on the risk of breast cancer is still uncertain. METHODS: Data from the Atherosclerosis Risk in Communities (ARIC) study, a prospective cohort of middle-aged women, were used to investigate the association of individual and combined cardiovascular risk factors with breast cancer. Cox proportional hazards models were applied to calculate the hazard ratio (HR) and 95% confidence intervals (CI). RESULTS: A total of 7501 women were included. During a mean follow-up of 19.7 years, 576 women were diagnosed with breast cancer. White women and premenopausal status were independently associated with increased risk of breast cancer. Of the individual cardiovascular risk factors, only obesity was independently associated with an increased risk of breast cancer (HR 1.29, 95% CI 1.04-1.61). Compared with women without cardiovascular risk factors, women having three or greater, but not those with fewer than three cardiovascular risk factors, had a significantly higher risk of developing breast cancer (HR 1.27, 95% CI 1.06-1.53). Subgroup analyses indicated that women with three or greater cardiovascular risk factors had higher risk of breast cancer among postmenopausal Black women, but not among premenopausal Black and White women. CONCLUSIONS: Combinations of cardiovascular risk factors are associated with increased risk of breast cancer in middle-aged women, especially in postmenopausal Black women. Joint interventions to modify cardiovascular risk factors could be used to prevent breast cancer in these higher-risk individuals.
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Neoplasias da Mama , Doenças Cardiovasculares , Neoplasias da Mama/diagnóstico , Doenças Cardiovasculares/epidemiologia , Estudos de Coortes , Feminino , Fatores de Risco de Doenças Cardíacas , Humanos , Incidência , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Prospectivos , Fatores de RiscoRESUMO
BACKGROUND: Lung function is constantly changing over the life course. Although the relation of cross-sectional lung function measure and adverse outcomes has been reported, data on longitudinal change and subsequent cardiovascular (CV) events risks are scarce. Therefore, this study is to determine the association of longitudinal change in lung function and subsequent cardiovascular risks. METHODS: This study analyzed the data from four prospective cohorts. Subjects with at least two lung function tests were included. We calculated the rate of forced respiratory volume in 1 s (FEV1) and forced vital capacity (FVC) decline for each subject and categorized them into quartiles. The primary outcome was CV events, defined as a composite of coronary heart disease (CHD), chronic heart failure (CHF), stroke, and any CV death. Cox proportional hazards regression and restricted cubic spline models were applied. RESULTS: The final sample comprised 12,899 participants (mean age 48.58 years; 43.61% male). Following an average of 14.79 (10.69) years, 3950 CV events occurred. Compared with the highest FEV1 quartile (Q4), the multivariable HRs for the lowest (Q1), 2nd (Q2), and 3rd quartiles (Q3) were 1.33 (95%CI 1.19, 1.49), 1.30 (1.16, 1.46), and 1.07 (0.95, 1.21), respectively. Likewise, compared with the reference quartile (Q4), the group that experienced a faster decline in FVC had higher HRs for CV events (1.06 [95%CI 0.94-1.20] for Q3, 1.15 [1.02-1.30] for Q2, and 1.28 [1.14-1.44] for Q1). The association remained robust across a series of sensitivity analyses and nearly all subgroups but was more evident in subjects < 60 years. CONCLUSIONS: We observed a monotonic increase in risks of CV events with a faster decline in FEV1 and FVC. These findings emphasize the value of periodic evaluation of lung function and open new opportunities for disease prevention.
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Insuficiência Cardíaca , Estudos Transversais , Feminino , Volume Expiratório Forçado , Humanos , Estudos Longitudinais , Pulmão , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Capacidade VitalRESUMO
Previous studies demonstrated that variants in dipeptidyl aminopeptidase-like protein-6 (DPP6) are involved in idiopathic ventricular fibrillation. However, its role in early repolarization syndrome (ERS) remains largely elusive. The aim of this study is to determine whether the novel DPP6-L747P variant is associated with ERS, and explore the underlying mechanisms. In our study, whole genome sequencing was used to identify a genetic variant in 4 Chinese families with sudden cardiac arrest induced by ERS. Then, wild-type (WT) DPP6 or mutant (c.2240Tâ¯>â¯C/p.L747P) DPP6 were respectively expressed in HEK293â¯cells, co-expressed with KV4.3 and KChIP2. Western blotting, immunofluorescence, and whole-cell patch clamp experiments were performed to reveal possible underlying mechanisms. A novel missense variant (c.2240Tâ¯>â¯C/p.L747P) in DPP6 was identified in the 4 families. Both DPP6-WT and DPP6-L747P were mainly located on the cell membrane. Compared with DPP6-WT, the intensity of DPP6 protein bands was downregulated in DPP6-L747P. Functional experiments showed that macroscopic currents exhibited an increase in DPP6-L747P, and the current intensity of DPP6-L747P was increased more than that of DPP6-WT (63.1 ± 8.2 pA/pF vs.86.5 ± 15.1 pA/pF at +50 mV, Pâ¯<â¯0.05). Compared with DPP6-WT, the slope of the activation curve of DPP6-L747P was slightly decreased (15.49⯱â¯0.56â¯mV vs. 13.88⯱â¯0.54â¯mV, Pâ¯<â¯0.05), the slope of the inactivation curve was increased (13.65⯱â¯1.57â¯mV, vs. 24.44⯱â¯2.79â¯mV, Pâ¯<â¯0.05) and the recovery time constant was significantly reduced (216.81⯱â¯18.59â¯ms vs. 102.11⯱â¯32.03â¯ms, Pâ¯<â¯0.05). In conclusion, we identified a novel missense variant (c.2240Tâ¯>â¯C/p. L747P) in DPP6 in 4 Chinese families with sudden cardiac arrest induced by ERS. Patch clamp experiments revealed that this variant could generate a gain of function of Ito and affect the potassium current. These results demonstrated that changes caused by the variant may be the underlying mechanisms of malignant arrhythmias in the individuals with ERS.
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Arritmias Cardíacas/genética , Povo Asiático/genética , Dipeptidil Peptidases e Tripeptidil Peptidases/genética , Mutação de Sentido Incorreto/genética , Proteínas do Tecido Nervoso/genética , Canais de Potássio/genética , Adolescente , Linhagem Celular , Membrana Celular/genética , Morte Súbita Cardíaca , Regulação para Baixo/genética , Família , Feminino , Células HEK293 , Humanos , MasculinoRESUMO
BACKGROUND: Early repolarization pattern (ERP) was associated with sudden cardiac death in recent studies. However, the associations between ERP and coronary artery disease (CAD), and ERP and cardiac death caused by acute myocardial infarction (MI) remains unclear. METHODS: We retrospectively enrolled consecutive 1,545 CAD patients and 908 non-CAD subjects as control group which were confirmed by coronary angiograph. The CAD patients include stable CAD, acute MI patients, and old MI patients. Multivariate logistic regression was employed to evaluate the relationship between ERP and CAD, and ERP and cardiac death caused by acute MI. RESULTS: Of the 1,545 CAD subjects, there were 1,029 stable CAD patients, 404 acute MI patients, and 112 old MI patients. The incidence of ERP was much higher among patients with CAD than without CAD subjects (20.1% vs. 6.2%, p < .001) after adjusting for major cardiovascular risk factors. No significant correlation was observed between lead region of ERP on 12-lead ECG and single abnormal artery. Of the 404 acute MI patients, 342 patients survived and 62 patients died. Incidence of ERP was higher in non-survivor than survivor patients with acute MI (24.2% vs. 17.5%, p = .006) after adjustment for major cardiovascular risk factors. CONCLUSION: The incidence of ERP was higher in CAD patients than subjects without CAD and in non-survivor patients than survivor patients with acute MI. The lead region of ERP on 12-lead ECG was not associated with single abnormal coronary artery.
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Doença da Artéria Coronariana/complicações , Doença da Artéria Coronariana/diagnóstico , Morte Súbita Cardíaca/etiologia , Eletrocardiografia/métodos , Infarto do Miocárdio/complicações , Doença Aguda , Estudos de Casos e Controles , China/epidemiologia , Doença da Artéria Coronariana/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/fisiopatologia , Estudos Retrospectivos , Medição de RiscoRESUMO
BACKGROUND: Acromegaly is highly associated with thyroid disorders. However, the clinical characteristics of thyroid nodules in individuals with acromegaly who present with thyroid diseases have not been completely elucidated. METHODS: Overall, 134 consecutive participants with growth hormone (GH)-secreting adenoma (n = 67) and non-functioning (NF) pituitary adenoma (n = 67) were recruited from the outpatient and inpatient patient department of The First Affiliated Hospital, Jinan University from August 2015 to August 2017. Thyroid ultrasonography was performed using an ultrasound system. The cytopathological results of fine-needle aspiration biopsy were analyzed by a pathologist according to the Bethesda system. Twenty-one patients with GH-secreting adenoma and thyroid disease underwent transsphenoidal pituitary adenoma resection and were followed up for 1 year. RESULTS: The prevalence of thyroid disease increased in the GH-secreting adenoma group compared with that in the NF pituitary adenoma group. The number of hypoechoic, isoechogenic, heterogeneous, and vascular thyroid nodules increased in patients with GH-secreting adenoma plus thyroid disease compared with that in patients with NF pituitary adenoma plus thyroid disease. Finally, we found significant decreases in the morphology of solid nodules and significant increases in the morphology of cystic nodules after surgery compared with those before surgery in the cured group. Moreover, the numbers of heterogeneous and vascular thyroid nodules decreased significantly after surgery compared with those before surgery in the cured group. However, the characteristics of the thyroid nodules did not change after surgery compared with those before surgery in the non-cured group. CONCLUSIONS: The numbers of hypoechoic, isoechoic, heterogeneous, and vascular thyroid nodules increased in patients with GH-secreting adenomas. In these patients, surgery resulted in significant changes from solid to cystic nodules and also reduced the numbers of heterogeneous and vascular thyroid nodules.
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Adenoma/fisiopatologia , Adenoma Hipofisário Secretor de Hormônio do Crescimento/fisiopatologia , Hormônio do Crescimento Humano/metabolismo , Doenças da Glândula Tireoide/epidemiologia , Hormônios Tireóideos/metabolismo , Nódulo da Glândula Tireoide/patologia , Adenoma/metabolismo , Adulto , Idoso , Feminino , Seguimentos , Adenoma Hipofisário Secretor de Hormônio do Crescimento/metabolismo , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Taiwan/epidemiologia , Doenças da Glândula Tireoide/diagnóstico , Doenças da Glândula Tireoide/diagnóstico por imagem , Doenças da Glândula Tireoide/metabolismo , Nódulo da Glândula Tireoide/diagnóstico por imagem , Nódulo da Glândula Tireoide/metabolismo , Ultrassonografia , Adulto JovemRESUMO
BACKGROUND: Recent studies have revealed that mutation in KCNE1, ß-subunits of cardiac potassium channel, involved in ventricular fibrillation. Whereas its role in early repolarization syndrome (ERS) is less well understood. OBJECTIVE: To study whether mutant in KCNE1 is associated with ERS and explore the possible underlying molecular mechanisms. METHODS: Whole genome from four unrelated families with ERS was amplified and sequenced. Wild-type (WT) KCNE1 and/or KCNE1-S38G (S38G) were expressed in HEK293 cells with KCNQ1. Functional studies included whole-cell patch-clamp, western blot and immunofluorescence were performed to reveal the possible underlying mechanisms. RESULTS: The co-expression of KCNE1-S38G and KCNQ1 decreased tail current density of IKs but had little effect in modulation channel kinetics of IKs. Compared with KCNE1-WT, the expression and membrane location of KCNE1-S38G decreased. Co-expression of KCNE1-WT and KCNE1-S38G partially rescued the function of IKs channel. CONCLUSIONS: The S38G mutation induced a loss-of-function of IKs due to decreasing of KCNE1 protein expression and defecting in KCNE1 protein membrane trafficking. Our findings suggested that KCNE1 may be one of the possible modulatory genes associated to ERS.
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Mutação/genética , Canais de Potássio de Abertura Dependente da Tensão da Membrana/genética , Adulto , Idoso , Predisposição Genética para Doença , Células HEK293 , Humanos , Masculino , Moduladores de Transporte de Membrana/metabolismo , Pessoa de Meia-Idade , Linhagem , Potássio/metabolismoRESUMO
Recent reports show that an early repolarization pattern (ERP) is associated with a higher incidence of sudden cardiac death in patients with obstructive coronary artery disease (CAD). Sporadic case studies have pointed out that ERP might be related to obstructive CAD.In consecutive patients who had undergone coronary angiography, we investigated the relationship between ERP and obstructive CAD by evaluating its association with coronary artery stenosis.The study population consisted of 3785 patients (59.9% men; mean age 63.1 years) with or without obstructive CAD. Adjusting for major cardiovascular risk factors, ERP was significantly associated with obstructive CAD (adjusted odds ratio (OR): 2.24 [95% CI 1.70-2.95]) with an incremental predictive value (ROC AUC 0.76 versus 0.71, P = 0.02; NRI 55.3%, P < 0.001; IDI = 0.05, P = 0.008), specifically in subjects with low risk and intermediate risk. ERP also significantly improved the predictive value for multi-vessel disease (AUC: 0.77 versus 0.72, P = 0.02 for two-vessel disease; 0.79 versus 0.73, P = 0.04 for three-vessel disease). ERP was consistently associated with stenoses of 3 main coronary arteries.ERP is associated with significant increased risk for obstructive CAD.Further studies are warranted to confirm our results and to elucidate the specific pathogenic mechanisms.
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Angiografia Coronária/métodos , Doença da Artéria Coronariana , Estenose Coronária , Vasos Coronários , Morte Súbita Cardíaca , Eletrocardiografia , China/epidemiologia , Angiografia Coronária/estatística & dados numéricos , Doença da Artéria Coronariana/complicações , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/epidemiologia , Doença da Artéria Coronariana/fisiopatologia , Estenose Coronária/diagnóstico por imagem , Estenose Coronária/fisiopatologia , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/fisiopatologia , Morte Súbita Cardíaca/epidemiologia , Morte Súbita Cardíaca/etiologia , Morte Súbita Cardíaca/prevenção & controle , Eletrocardiografia/métodos , Eletrocardiografia/estatística & dados numéricos , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Medição de Risco/métodos , Fatores de Risco , Índice de Gravidade de DoençaRESUMO
BACKGROUND: Abnormal cardiac ion channels current, including transient outward potassium current (Ito ), is associated with early repolarization syndrome (ERS). Previous studies showed that mutations in SCN1Bß both to increase the Ito current and to decrease the sodium current. Yet its role in ERS remains unknown. OBJECTIVE: To determine the role of mutations in the SCN1Bß subunits in ERS. METHODS: We screened for mutations in the SCN1B genes from four families with ERS. Wild-type and mutant SCN1Bß genes were co-expressed with wild-type KCND3 in human embryonic kidney cells (HEK293). Whole-cell patch-clamp technique and co-immunoprecipitation were used to study the electrophysiological properties and explore the underlying mechanisms. RESULTS: S248R and R250T mutations in SCN1Bß were detected in 4 families' probands. Neither S248R nor R250T mutation had significant influence on the sodium channel current density (INa ) when co-expressed with SCN5A/WT. Co-expression of KCND3/WT and SCN1Bß/S248R or SCN1Bß/R250T increased the transient outward potassium current Ito by 27.44% and 199.89%, respectively (P < 0.05 and P < 0.01, respectively) when compared with SCN1Bß/WT. Electrophysiological properties showed that S248R and R250T mutations decreased the steady-state inactivation and recovery from inactivation of Ito channel. Co-immunoprecipitation study demonstrated an increased association between SCN1Bß mutations and Kv4.3 compared with SCN1Bß/WT (P < 0.05 and P < 0.01, respectively). CONCLUSION: The S248R and R250T mutations of SCN1Bß gene caused gain-of-function of Ito by associated with Kv4.3, which maybe underlie the ERS phenotype of the probands.
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Morte Súbita Cardíaca/patologia , Coração/fisiopatologia , Canais de Potássio Shal/genética , Subunidade beta-1 do Canal de Sódio Disparado por Voltagem/genética , Adulto , Idoso , Animais , Eletrofisiologia , Feminino , Predisposição Genética para Doença , Células HEK293 , Coração/diagnóstico por imagem , Humanos , Masculino , Potenciais da Membrana , Mutação/genética , Técnicas de Patch-Clamp , TransfecçãoRESUMO
BACKGROUND/AIMS: Early repolarization syndrome (ERS) has been recently recognized as early repolarization pattern with idiopathic ventricular fibrillation. However, the genetic background of ERS has not been fully understood. METHODS: A Chinese family with sudden cardiac death associated with ERS was investigated. Direct sequencing of ERS susceptibility genes was performed on the proband and family members. Whole-cell patch-clamp methods were used to characterize the mutant channel expressed in HEK 293 cells. RESULTS: One missense mutation (p. K801T) was found in the hERG (KCNH2 gene) by the direct sequencing of candidate genes. Whole cell voltage clamp studies of the K801T mutation in HEK 293 cells demonstrated a 1.5-fold increase in maximum steady state current (37.2±7.3 vs 20.3±4.4 pA/pF) that occurred at a 20 mV more positive potential compared to the wild type channels. The voltage dependence of inactivation was significantly shifted in the positive voltage direction (WT -59.5±1.4 vs K801T -44.3±1.2 mV). Kinetic analysis revealed slower inactivation rates of K801T, but faster rates of activation and deactivation. The hERG channel blockers tested inhibited K801T-hERG channel in concentration response, and the potencies of these drugs can be rank-ordered as follows: quinidine> disopyramide> sotalol> flecainide. CONCLUSION: Our study indicated that the K801T mutation caused the gain of function of hERG channels that may account for the clinical phenotype of ERS. Quinidine and disopyramide could improve the function of K801T-hERG mutant channel, and may be therapeutic options for patients with the K801T hERG mutation.
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Canal de Potássio ERG1/genética , Mutação de Sentido Incorreto , Fibrilação Ventricular/genética , Adulto , Morte Súbita Cardíaca/etiologia , Células HEK293 , Heterozigoto , Humanos , Masculino , Linhagem , Fibrilação Ventricular/complicaçõesRESUMO
BACKGROUND: A slower heart rate can exaggerate J-point elevation in a 12-lead ECG. This study examined the role of Holter monitoring in the diagnosis of early repolarisation pattern (ERP). METHODS: We examined 24-hour Holter recordings of 4000 consecutive patients seen at an outpatient clinic, and found 500 patients (12.5%) with ERP (based on J-point elevation magnitude maximum value≥0.1mV on the Holter recording). The highest magnitude of J-point elevation, R wave amplitude, the ratio between J-point elevation magnitude and R-wave amplitude on the same ECG lead (J/R ratio), QRS interval, and QT/QTc interval were measured on the Holter recording and on a surface 12-lead ECG of the 500 patients with ERP. The magnitude of J-point elevation, J/R ratio, and QT/QTc interval were compared between three groups: nighttime Holter recording, daytime Holter recording, and daytime surface 12-lead ECG. RESULTS: The magnitude of J-point elevation of the nighttime Holter (0.20±0.10mV) was higher than that of the daytime in Holter (0.12±0.07mV, p<0.001) and the 12-lead ECG (0.12±0.06mV, p<0.001). There was no statistical difference in magnitude of J-point elevation between daytime Holter and surface 12-lead ECG. While all 500 patients were diagnosed with ERP based on J-point elevation maximum value J-point on Holter monitoring, only 425 (85%) patients could be diagnosed with ERP based on the surface 12-lead ECG. The J-point elevation maximum value on the nighttime Holter was negatively correlated with heart rate (r=-0.15, p=0.0007) and QTc (r=-0.13, p=0.0043), and positively correlated with R wave amplitude (r=0.46, p<0.0001), J/R ratio (r=0.69, p<0.0001), and QRS interval (r=0.29, p<0.0001). CONCLUSIONS: The J-point elevation on nighttime Holter recording was higher than that on daytime Holter and daytime surface 12-lead ECG, and there was misdiagnosis of ERP based on daytime surface 12-lead ECG. Holter monitoring has a complementary role in the diagnosis of ERP, especially in patients with a suspected diagnosis of ERP based on daytime surface 12-lead ECG.
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Arritmias Cardíacas/diagnóstico , Diagnóstico Precoce , Eletrocardiografia Ambulatorial/métodos , Sistema de Condução Cardíaco/fisiopatologia , Frequência Cardíaca/fisiologia , Arritmias Cardíacas/fisiopatologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Fatores de TempoRESUMO
BACKGROUND AND PURPOSE: Chronic kidney disease may increase the risk for ischemic stroke or systemic embolism in patients with nonvalular atrial fibrillation (AF). We conducted a meta-analysis to summarize all published studies to investigate the link between chronic kidney disease and risk of thromboembolic events in AF. METHODS: We performed a literature search using MEDLINE (source PubMed, 1966 to July, 2014) and EMBASE (1980 to July 2014) with no restrictions. Pooled effect estimates were obtained by using random-effects meta-analysis. RESULTS: Eighteen studies involving 538 479 patients and 41 719 incident thromboembolic events were identified. From the pooled analysis, AF patients with estimated glomerular filtration rate <60 mL/min compared with those with estimated glomerular filtration rate ≥60 mL/min experienced a significantly increased risk for developing thromboembolic events (relative risk, 1.62 [95% confidence interval, 1.40-1.87; P<0.001]). The annual rate of thromboembolic events increased by 0.41% (95% confidence interval, 0.17%-0.65%) for a 10 mL/min decrease in renal function. Addition of renal impairment to CHADS2 slightly improved the stroke risk stratification. CONCLUSIONS: Impaired renal function is an independent predictor of stroke or systemic embolism in patients with nonvalvular AF. Consideration of renal function may improve stroke risk stratification in patients with AF.
Assuntos
Fibrilação Atrial/complicações , Insuficiência Renal Crônica/complicações , Acidente Vascular Cerebral/etiologia , Tromboembolia/etiologia , Taxa de Filtração Glomerular , Humanos , Insuficiência Renal Crônica/fisiopatologia , Fatores de Risco , Índice de Gravidade de DoençaRESUMO
OBJECTIVES: To investigate the effects and mechanisms of Nardostachys chinensis (NC) on spontaneous ventricular arrhythmias in rats with hyper-acute myocardial infarction (AMI). METHODS: Seventy-two rats were randomly divided into the control group (n = 24), metoprolol group (n = 24), and the NC group (n = 24). Premature ventricular contractions (PVCs), ventricular tachycardias (VTs), ventricular fibrillations (VFs), and blood pressure were monitored for 4 hours after coronary artery ligation. The connexin 43 (Cx43) expression in ventricular myocardium was measured by immunohistochemistry, Western blot, and real-time RT-PCR. RESULTS: Compared with the control, metoprolol and NC decreased the VF incidence (50% vs. 4.2%, P < 0.001, and 50% vs. 12.5%, P = 0.005, respectively). There was a steady decrease in the cumulative number of PVCs and VTs within 4 hours from ligating in 3 groups. Compared with the control, metoprolol and NC reduced the cumulative number of VTs and PVCs. Compared with control, metoprolol and NC decreased the infarct size of the left ventricular tissue (55.98% ± 6.20% vs. 39.13% ± 4.53%, P < 0.001, and 55.98% ± 6.20% vs. 42.39% ± 3.44%, P < 0.001, respectively). The results from immunohistochemistry, Western blot, and real-time RT-PCR showed that the protein expression of Cx43 in the control group was significantly lower than that in the metoprolol and NC groups in the infarcted zone. CONCLUSIONS: NC decreased the incidence of spontaneous ventricular arrhythmias (especially VF), reduced Cx43 degradation, and improved Cx43 redistribution in myocardial infarcted zone in rats with hyper-AMI. The data of the present study indicated that NC may be a promising drug in the future to prevent patients with AMI from lethal ventricular arrhythmias in prehospital setting.
Assuntos
Antiarrítmicos/uso terapêutico , Medicamentos de Ervas Chinesas/uso terapêutico , Infarto do Miocárdio/tratamento farmacológico , Nardostachys/química , Taquicardia Ventricular/prevenção & controle , Fibrilação Ventricular/prevenção & controle , Complexos Ventriculares Prematuros/prevenção & controle , Animais , Antiarrítmicos/administração & dosagem , Pressão Sanguínea/efeitos dos fármacos , Western Blotting , Conexina 43/metabolismo , Medicamentos de Ervas Chinesas/administração & dosagem , Eletrocardiografia , Feminino , Imuno-Histoquímica , Masculino , Metoprolol/administração & dosagem , Metoprolol/uso terapêutico , Infarto do Miocárdio/complicações , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo Real , Rizoma/química , Taquicardia Ventricular/etiologia , Taquicardia Ventricular/metabolismo , Taquicardia Ventricular/patologia , Fibrilação Ventricular/etiologia , Fibrilação Ventricular/metabolismo , Fibrilação Ventricular/patologia , Complexos Ventriculares Prematuros/etiologia , Complexos Ventriculares Prematuros/metabolismo , Complexos Ventriculares Prematuros/patologiaRESUMO
PURPOSE: Previous studies regarding the association between carrot intake and prostate cancer risk have reported inconsistent results. We conducted a meta-analysis to summarize evidence on this association and to quantify the potential dose-response relationship. METHOD: A systematic literature search of papers published in August 2013 was conducted using PubMed, EMBASE, Scopus, Web of Science, the Cochrane register, and the Chinese National Knowledge Infrastructure databases, and the references of the retrieved articles were screened. The summary risk estimates with 95% confidence intervals (CIs) for the highest versus the lowest intake of carrots were calculated. A dose-response meta-analysis was also conducted for the studies reporting categorical risk estimates for a series of exposure levels. RESULTS: We found a significantly decreased risk of prostate cancer associated with the intake of carrots (odds ratio 0.82, 95% CI 0.70-0.97). In addition, the dose-response meta-analysis indicated that for each serving per week, or 10 g per day increment of carrot intake, the risk estimate of prostate cancer was 0.95 (0.90-0.99) or 0.96 (0.94-0.99). There was no evidence of significant publication bias based on Begg's funnel plot (P = 1.000) or Egger's test (P = 0.804). CONCLUSION: Carrot intake might be inversely associated with prostate cancer risk. Because of the limited number of cohort studies and substantial heterogeneity observed between studies in this meta-analysis, further well-designed prospective studies are warranted to confirm the findings from our study.
Assuntos
Daucus carota , Dieta , Neoplasias da Próstata/epidemiologia , Bases de Dados Factuais , Humanos , Masculino , Estudos Observacionais como Assunto , Fatores de Risco , Sensibilidade e EspecificidadeRESUMO
AIMS: Cardiovascular health (CVH) has been proven to reduce cardiovascular disease burden and mortality, but data are lacking regarding cardiac arrhythmias. The aim of this study was to assess the association between CVH metrics and atrial fibrillation/flutter (AF), ventricular arrhythmias, and bradyarrhythmias. METHODS AND RESULTS: This study analysed data from the Atherosclerosis Risk in Communities (ARIC) cohort, with participants recruited from four different communities across the United States. Cardiovascular health metrics were scored at baseline (1987-89) following the American Heart Association's recommendations and categorized as poor, intermediate, or ideal. Arrhythmia episodes were diagnosed by International Classification of Diseases (ICD)-9 code. Adjusted associations were estimated using Cox models and event rates and population attributable fractions were calculated by CVH metrics category. The study population consisted of 13 078 participants, with 2548 AF, 1363 ventricular arrhythmias, and 706 bradyarrhythmias occurred. The adjusted hazard ratios (HRs) for ideal (vs. poor) CVH metrics were 0.59 [95% confidence interval (CI): 0.50-0.69] for AF, 0.38 (95% CI: 0.28-0.51) for ventricular arrhythmias, and 0.70 (95% CI: 0.51-0.97) for bradyarrhythmia. The risk of incident arrhythmias decreased steadily as the CVH metrics improved from 0 to 14 scores. The adjusted population attributable fractions were calculated to be 29.9% for AF, 54.4% for ventricular arrhythmias, and 21.9% for bradyarrhythmia, respectively. The association between CVH metrics and incident arrhythmias was also seen in people who remained free of coronary heart disease over the follow-up. CONCLUSION: Achieving ideal CVH metrics recommendations by AHA in midlife was associated with a lower risk of incident arrhythmias later in life.
Intermediate and ideal levels of cardiovascular health (CVH) metrics are associated with a markedly reduced risk of developing incident arrhythmias, including atrial fibrillation/flutter, ventricular arrhythmias, and bradyarrhythmia, independent of coronary heart disease. A majority of incident arrhythmias could be prevented if the risk profile of the entire population was optimized. These findings emphasize the significance of public health policies that improve CVH to reduce the social and economic burden of arrhythmias.
Assuntos
Fibrilação Atrial , Doenças Cardiovasculares , Sistema Cardiovascular , Humanos , Estados Unidos , Bradicardia , Fatores de Risco , Indicadores de Qualidade em Assistência à Saúde , Doenças Cardiovasculares/epidemiologia , Nível de SaúdeRESUMO
INTRODUCTION: The present study aimed to examine the correlation between serum cytokine levels and the incidence of coronary artery disease (CAD), a leading cause of mortality globally, which is known to have a strong association with inflammatory factors. The study further sought to determine the predictors of CAD to distinguish patients with coronary artery lesions from those suspected of having CAD. METHODS AND RESULTS: In this study, 487 patients who underwent coronary angiography as a result of suspected CAD but without acute myocardial infarction (AMI) were recruited. The serum levels of the cytokines interleukin (IL)-1ß, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-17, tumor necrosis factor-α, interferon (IFN)-α, and IFN-γ were measured using a multiplexed particle-based flow cytometric assay technique. The results of the study revealed that the levels of IL-4, IL-12p70, IL-17, IFN-α, and IFN-γ in the CAD group were significantly lower compared to those in the non-CAD group. Multivariate logistic regression analysis indicated that two serum cytokines (IL-4 and IL-17), one protective factor (high-density lipoprotein cholesterol [HDL-C]), and three risk factors (sex, smoking, and diabetes) were independently predictive of CAD. The receiver operating characteristic curve analysis showed that the combined use of these predictors in a multivariate model demonstrated good predictive performance for CAD, as evidenced by an area under the curve value of 0.826. CONCLUSION: The results of the study indicated that serum IL-4 and IL-17 levels serve as independent predictors of CAD. The risk prediction model established in the research, which integrates these serum cytokines (IL-4 and IL-17) with relevant clinical risk factors (gender, smoking, and diabetes) and the protective factor HDL-C, holds the potential to differentiate patients with CAD from those suspected of having CAD but without AMI.