RESUMO
BACKGROUND: Advanced atrioventricular block (AVB), that is, higher than second-degree Mobitz-1, is an abnormal finding in athletes. Despite intensive investigation, in several cases the pathogenesis remains unknown, but frequently pacemaker implantation is still indicated. Increasing evidence points to circulating anti-Ro/Sjögren syndrome-related antigen A (SSA) antibodies cross-reacting with L-type calcium channel and inhibiting the related current as an epidemiologically relevant and potentially reversible cause of isolated AVB in adults. The aim of the study was to determine the prevalence of anti-Ro/SSA-associated advanced AVBs in a large sample of young athletes. METHODS AND RESULTS: A total of 2536 consecutive athletes aged <40 years without a history of cardiac diseases/interventions were enrolled in a cross-sectional study. Resting and exercise electrocardiography was performed, and those presenting any AVB were further evaluated by 24-hour Holter ECG. Athletes with second-degree AVBs and their mothers underwent anti-Ro/SSA testing. Moreover, purified immunoglobulin G from subjects with anti-Ro/SSA-positive and anti-Ro/SSA-negative advanced AVB were tested on L-type calcium current and L-type-calcium channel expression using tSA201 cells. The global prevalence of advanced AVB in the overall sample was ≈0.1%, but the risk considerably increased (2%) when intensely trained postpubertal male subjects were selectively considered. While none of the athletes with advanced AVB showed heart abnormalities, in 100% of cases anti-Ro/SSA antibodies were detected. Ex vivo experiments showed that immunoglobulin G from anti-Ro/SSA-positive but not -negative subjects with advanced AVB acutely inhibit L-type calcium current and chronically downregulate L-type-calcium channel expression. CONCLUSIONS: Our study provides evidence that advanced AVB occurs in young athletes, in most cases associated with anti-Ro/SSA antibodies blocking L-type calcium channels. These findings may open new avenues for immunomodulating therapies to reduce the risk of life-threatening events in athletes, avoiding or delaying pacemaker implantation.
Assuntos
Anticorpos Antinucleares , Atletas , Bloqueio Atrioventricular , Canais de Cálcio Tipo L , Humanos , Masculino , Feminino , Adulto , Estudos Transversais , Bloqueio Atrioventricular/imunologia , Bloqueio Atrioventricular/epidemiologia , Bloqueio Atrioventricular/diagnóstico , Prevalência , Adulto Jovem , Canais de Cálcio Tipo L/imunologia , Anticorpos Antinucleares/sangue , Anticorpos Antinucleares/imunologia , Adolescente , Eletrocardiografia Ambulatorial , Ribonucleoproteínas/imunologiaRESUMO
BACKGROUND: During acute infections, the risk of malignant ventricular arrhythmias is increased, partly because of a higher propensity to develop QTc prolongation. Although it is generally believed that QTc changes almost exclusively result from concomitant treatment with QT-prolonging antimicrobials, direct effects of inflammatory cytokines on ventricular repolarization are increasingly recognized. We hypothesized that systemic inflammation per se can significantly prolong QTc during acute infections, via cytokine-mediated changes in K+ channel expression. METHODS: We evaluated (1) the frequency of QTc prolongation and its association with inflammatory markers, in patients with different types of acute infections, during active disease and remission; (2) the prevalence of acute infections in a cohort of consecutive patients with Torsades de Pointes; (3) the relationship between K+ channel mRNA levels in ventricles and peripheral blood mononuclear cells and their changes in patients with acute infection over time. RESULTS: In patients with acute infections, regardless of concomitant QT-prolonging antimicrobial treatments, QTc was significantly prolonged but rapidly normalized in parallel to CRP (C-reactive protein) and cytokine level reduction. Consistently in the Torsades de Pointes cohort, concomitant acute infections were highly prevalent (30%), despite only a minority (25%) of these cases were treated with QT-prolonging antimicrobials. KCNJ2 K+ channel expression in peripheral blood mononuclear cell, which strongly correlated to that in ventricles, inversely associated to CRP and IL (interleukin)-1 changes in acute infection patients. CONCLUSIONS: During acute infections, systemic inflammation rapidly induces cytokine-mediated ventricular electrical remodeling and significant QTc prolongation, regardless concomitant antimicrobial therapy. Although transient, these changes may significantly increase the risk of life-threatening ventricular arrhythmia in these patients. It is timely and warranted to transpose these findings to the current coronavirus disease 2019 (COVID-19) pandemic, in which both increased amounts of circulating cytokines and cardiac arrhythmias are demonstrated along with a frequent concomitant treatment with several QT-prolonging drugs. Graphic Abstract: A graphic abstract is available for this article.
Assuntos
Doenças Transmissíveis/metabolismo , Citocinas/metabolismo , Parada Cardíaca/metabolismo , Frequência Cardíaca , Ventrículos do Coração/metabolismo , Inflamação/metabolismo , Leucócitos Mononucleares/metabolismo , Canais de Potássio Corretores do Fluxo de Internalização/metabolismo , Torsades de Pointes/metabolismo , Potenciais de Ação , Doença Aguda , Adulto , Idoso , Idoso de 80 Anos ou mais , Anti-Infecciosos/efeitos adversos , Doenças Transmissíveis/tratamento farmacológico , Doenças Transmissíveis/epidemiologia , Doenças Transmissíveis/fisiopatologia , Feminino , Parada Cardíaca/epidemiologia , Parada Cardíaca/fisiopatologia , Frequência Cardíaca/efeitos dos fármacos , Ventrículos do Coração/efeitos dos fármacos , Ventrículos do Coração/fisiopatologia , Humanos , Inflamação/epidemiologia , Inflamação/fisiopatologia , Leucócitos Mononucleares/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Canais de Potássio Corretores do Fluxo de Internalização/genética , Prevalência , Fatores de Risco , Transdução de Sinais , Fatores de Tempo , Torsades de Pointes/epidemiologia , Torsades de Pointes/fisiopatologia , Adulto JovemRESUMO
Background Systemic inflammation is a strong predictor of atrial fibrillation. A key role for electrical remodeling is increasingly recognized, and experimental data suggest that inflammatory cytokines can directly affect connexins resulting in gap-junction dysfunction. We hypothesized that systemic inflammation, regardless of its origin, promotes atrial electric remodeling in vivo, as a result of cytokine-mediated changes in connexin expression. Methods and Results Fifty-four patients with different inflammatory diseases and elevated C-reactive protein were prospectively enrolled, and electrocardiographic P-wave dispersion indices, cytokine levels (interleukin-6, tumor necrosis factor-α, interleukin-1, interleukin-10), and connexin expression (connexin 40, connexin 43) were measured during active disease and after reducing C-reactive protein by >75%. Moreover, peripheral blood mononuclear cells and atrial tissue specimens from an additional sample of 12 patients undergoing cardiac surgery were evaluated for atrial and circulating mRNA levels of connexins. Finally, in vitro effects of interleukin-6 on connexin expression were studied in HL-1 mouse atrial myocytes. In patients with active inflammatory diseases, P-wave dispersion indices were increased but rapidly decreased within days when C-reactive protein normalizes and interleukin-6 levels decline. In inflammatory disease patients, both P-wave dispersion indices and interleukin-6 changes were inversely associated with circulating connexin levels, and a positive correlation between connexin expression in peripheral blood mononuclear cells and atrial tissue was demonstrated. Moreover, interleukin-6 significantly reduced connexin expression in HL-1 cells. Conclusions Our data suggest that regardless of specific etiology and organ localization, systemic inflammation, via interleukin-6 elevation, rapidly induces atrial electrical remodeling by down-regulating cardiac connexins. Although transient, these changes may significantly increase the risk for atrial fibrillation and related complications during active inflammatory processes.
Assuntos
Remodelamento Atrial/imunologia , Conexinas/genética , Inflamação/imunologia , Interleucina-6/imunologia , Miócitos Cardíacos/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Antibacterianos/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Artrite Reumatoide/imunologia , Remodelamento Atrial/genética , Proteína C-Reativa/imunologia , Procedimentos Cirúrgicos Cardíacos , Conexina 43/efeitos dos fármacos , Conexina 43/genética , Conexina 43/metabolismo , Conexinas/efeitos dos fármacos , Conexinas/metabolismo , Eletrocardiografia , Feminino , Regulação da Expressão Gênica , Átrios do Coração/citologia , Humanos , Infecções/tratamento farmacológico , Infecções/imunologia , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Inflamação/fisiopatologia , Interleucina-1/imunologia , Interleucina-10/imunologia , Interleucina-6/farmacologia , Masculino , Camundongos , Pessoa de Meia-Idade , RNA Mensageiro/metabolismo , Fator de Necrose Tumoral alfa/imunologia , Adulto Jovem , Proteína alfa-5 de Junções ComunicantesRESUMO
Background: Torsades de pointes (TdP) is a life-threatening ventricular tachycardia occurring in long QT-syndrome patients. It usually develops when multiple QT-prolonging factors are concomitantly present, more frequently drugs and electrolyte imbalances. Since proton-pump inhibitors (PPIs)-associated hypomagnesemia is an increasingly recognized adverse event, PPIs were recently included in the list of drugs with conditional risk of TdP, despite only few cases of TdP in PPI users have been reported so far. Objectives: Aim of the present study is to evaluate whether PPI-induced hypomagnesemia actually has a significant clinical impact on the risk of TdP in the general population. Methods: Forty-eight unselected patients who experienced TdP were consecutively enrolled (2008-2017). Shortly after the first TdP episode, in those patients who did not receive magnesium sulfate and/or potassium or calcium replacement therapy, serum electrolytes were measured and their relationship with PPI usage analyzed. Results: Many patients (28/48, 58%) were under current PPI treatment when TdP occurred. Among TdP patients in whom serum electrolyte determinations were obtained before replacement therapy (27/48), those taking PPIs had significantly lower serum magnesium levels than those who did not. Hypomagnesemia occurred in ~40% of patients receiving PPIs (6/14), in all cases after an extended treatment (>2 weeks). In patients taking PPIs the mean QT-prolonging risk factor number was significantly higher than in those who did not, a difference which was mainly driven by lower magnesium levels. Conclusions: In unselected TdP patients, PPI-induced hypomagnesemia was common and significantly contributed to their cumulative arrhythmic risk. By providing clinical support to current recommendations, our data confirm that more awareness is needed when a PPI is prescribed, specifically as regards the risk of life-threatening arrhythmias.
Assuntos
Crioglobulinemia/etiologia , Infecções por Parvoviridae/complicações , Vasculite/etiologia , Doença Aguda , Idoso , Anticorpos Antivirais/análise , Crioglobulinemia/sangue , Crioglobulinemia/diagnóstico , DNA Viral/análise , Humanos , Imunoglobulinas/sangue , Masculino , Infecções por Parvoviridae/diagnóstico , Infecções por Parvoviridae/virologia , Parvovirus B19 Humano/genética , Parvovirus B19 Humano/imunologia , Vasculite/diagnósticoRESUMO
OBJECTIVE: Increasing evidence indicates systemic inflammation as a new potential cause of acquired long QT syndrome (LQTS), via cytokine-mediated changes in cardiomyocyte ion channels. Torsade de pointes (TdP) is a life-threatening polymorphic ventricular tachycardia occurring in patients with LQTS, usually when multiple QT-prolonging factors are simultaneously present. Since classical risk factors cannot fully explain TdP events in a number of patients, we hypothesised that systemic inflammation may represent a currently overlooked risk factor contributing to TdP development in the general population. METHODS: Forty consecutive patients who experienced TdP (TdP cohort) were consecutively enrolled and circulating levels of C-reactive protein (CRP) and proinflammatory cytokines (interleukin-6 (IL-6), tumour necrosis factor alpha (TNFα), interleukin-1 (IL-1)) were compared with patients with active rheumatoid arthritis (RA), comorbidity or healthy controls. An additional 46 patients with different inflammatory conditions (acute infections, n=31; immune-mediated diseases, n=12; others, n=3) and elevated CRP (inflammatory cohort) were prospectively enrolled, and corrected QT (QTc) and cytokine levels were measured during active disease and after a CRP decrease of >75% subsequent to therapy. RESULTS: In the TdP cohort, 80% of patients showed elevated CRP levels (median: ~3 mg/dL), with a definite inflammatory disease identifiable in 18/40 cases (acute infections, n=12; immune-mediated diseases, n=5; others, n=1). In these subjects, IL-6, but not TNFα and IL-1, was ~15-20 times higher than in controls, and comparable to RA patients. In the inflammatory cohort, where QTc prolongation was common (mean values: 456.6±30.9 ms), CRP reduction was associated with IL-6 level decrease and significant QTc shortening (-22.3 ms). CONCLUSION: The data are first to show that systemic inflammation via elevated IL-6 levels may represent a novel QT-prolonging risk factor contributing to TdP occurrence in the presence of other classical risk factors. If confirmed, this could open new avenues in antiarrhythmic therapy.