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1.
Int Heart J ; 62(2): 320-328, 2021 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-33731538

RESUMO

Second-generation cryoballoon (CB) ablation is effective in achieving pulmonary vein (PV) isolation (PVI) in atrial fibrillation (AF) patients. The "crosstalk" (CST) phenomenon has been reported to reduce unnecessary applications during CB ablation. Nevertheless, it is unclear under what conditions the CST phenomenon occurs.To seek the predictors of the CST phenomenon during CB-guided PVI, CST phenomenon in achieving ipsilateral superior PVI during inferior PV ablation was analyzed in AF patients who underwent de novo ablation using CB. CB occlusion status and nadir balloon temperature (NT) were compared in these patients, and all ablated superior PVs were categorized into three groups according to the necessity of the touch up ablation and effectiveness of the phenomenon.Of 1082 superior PVs, 16, 40, and 1026 were classified into the CST success, CST failure, and control groups (unnecessary CST), respectively. The proportion of superior PVs ablated with complete occlusion using the CB was significantly higher in the CST success group than in the other two groups. The proportion of superior PVs ablated with NT ≤ -46°C was higher in the CST success group than in the CST failure group. The CST phenomenon was always observed if CB ablation of the superior PVs was performed with both complete occlusion and NT ≤ -46°C and was almost always ineffective if it did not meet these two criteria (sensitivity, 100%; specificity, 93%).Successful CST ablation was highly predicted if complete PV occlusion and NT ≤ -46°C during CB ablation of the superior PVs were achieved.


Assuntos
Fibrilação Atrial/cirurgia , Criocirurgia/métodos , Sistema de Condução Cardíaco/fisiopatologia , Veias Pulmonares/cirurgia , Idoso , Fibrilação Atrial/fisiopatologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
2.
Ann Thorac Surg ; 111(4): e295-e296, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33419566

RESUMO

Cardiac sympathetic denervation (CSD) for refractory ventricular tachycardia (VT) has been shown to decrease VT recurrence and defibrillator shocks in patients with ischemic and nonischemic cardiomyopathy. Here and in the accompanying Video, we demonstrate the technique for minimally invasive CSD, highlight important technical points, and report surgical outcomes. CSD is accomplished through bilateral resection of the inferior one-third to one-half of the stellate ganglion en bloc with T2-T4 sympathectomy. Despite the high potential for perioperative risk, most patients do not have serious complications. We find that surgical CSD can be performed safely in an attempt to liberate patients from refractory VT.


Assuntos
Ganglionectomia/métodos , Sistema de Condução Cardíaco/fisiopatologia , Frequência Cardíaca/fisiologia , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Taquicardia Ventricular/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Taquicardia Ventricular/fisiopatologia , Vértebras Torácicas
3.
Int Heart J ; 62(1): 78-86, 2021 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-33390564

RESUMO

Left bundle branch pacing (LBBP) has been adopted as a new pacing therapy whether in routine pacing or patients with heart failure, but the criteria for a completely captured LBBP are too complicated and have a low success rate in routine clinical practice.Consecutive patients with pacing therapy indications were enrolled. Left bundle branch area pacing (LBBAP) was conducted, and the presence of LBB potential, paced QRS duration, stimulus to left ventricular activation time (Stim-LVAT), and LBB potential to left ventricular activation time (LBB po-LVAT) were determined and utilized to characterize LBBAP modalities. Pacing parameters and safety were assessed at 6-month follow-up. LBBAP succeeded in 95.6% of patients (103/106) who completed the 6-month follow-up. Complete LBBP was achieved in 21 (20%) patients, characterized with a short Stim-LVAT equal to LBB po-LVAT. Incomplete LBBP was achieved in 58 (56%) patients with a short Stim-LVAT equal to LBB po-LVAT at a high pacing output and a relatively longer Stim-LVAT at a low pacing output. Deep septal pacing (DSP) characterized with no LBB potential and a longer Stim-LVAT (83.3 ± 7.7 ms) than that in LBBP (71.37 ± 7.1 ms, P < 0.01 versus DSP) was observed in 24 (23%) patients. Complete LBBP had a longer total procedure time and longer fluoroscopic time than the other two groups.This study describes the similarities and differences in electrophysiological characteristics and the possible mechanisms of the different types of LBBAP, classified into 3 modalities in routine clinical practice, each with narrow paced QRS duration and stable parameters, indicating LBBAP can be a near-physiological pacing modality.


Assuntos
Bloqueio de Ramo/terapia , Estimulação Cardíaca Artificial/métodos , Sistema de Condução Cardíaco/fisiopatologia , Insuficiência Cardíaca/terapia , Idoso , Idoso de 80 Anos ou mais , Bloqueio de Ramo/fisiopatologia , Eletrofisiologia Cardíaca/métodos , Ecocardiografia/métodos , Eletrocardiografia/métodos , Fenômenos Eletrofisiológicos , Feminino , Seguimentos , Insuficiência Cardíaca/fisiopatologia , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Estudos Prospectivos , Septo Interventricular/fisiopatologia
4.
Int Heart J ; 62(1): 72-77, 2021 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-33455989

RESUMO

Atrioventricular nodal reentry tachycardia (AVNRT) is the most common regular supraventricular tachycardia (SVT). Slow pathway modification (SPM) is the accepted first line treatment with reported success rates around 95%. Information regarding possible predictors of AVNRT recurrence is scarce.Out of 4170 consecutive patients with SPM in our department from 1993-2018, we identified 78 patients (1.9%) receiving > 1 SPM (69% female, median age 50 years) with a recurrence of AVNRT after a successful SPM. We matched these patients for age, gender and number of radiofrequency applications during first SPM with 78 patients who received one successful SPM in our center without AVNRT recurrence. Both groups were analyzed for possible predictors of a recurrence of AVNRT during long-term follow-up. The recurrence group contained a significantly lower proportion of patients with an occurrence of junctional beats during SPM (69% versus 89%, P = 0.006). Moreover, significantly more cases of previously diagnosed atrial fibrillation/tachycardia (AF/AT; 21% versus 5%, P = 0.007) and inducible AF/AT during electrophysiology study (23% versus 6%, P = 0.006) were present in the recurrence group. While more than half of patients had a recurrence within the first year, in 20% symptoms reappeared ≥ 4 years after ablation.In a small percentage of patients, AVNRT recurs after an initially successful ablation. Interestingly, these patients had significantly fewer junctional beats during ablation and a higher rate of other (inducible) arrhythmias. AVNRT recurrence spanned a considerable timeframe and should remain a differential diagnosis, even years after ablation.


Assuntos
Nó Atrioventricular/fisiopatologia , Fascículo Atrioventricular/cirurgia , Ablação por Cateter/métodos , Taquicardia por Reentrada no Nó Atrioventricular/fisiopatologia , Adulto , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/fisiopatologia , Fibrilação Atrial/cirurgia , Nó Atrioventricular/cirurgia , Fascículo Atrioventricular/fisiopatologia , Eletrofisiologia Cardíaca/métodos , Eletrofisiologia Cardíaca/estatística & dados numéricos , Estudos de Casos e Controles , Diagnóstico Diferencial , Eletrocardiografia/métodos , Feminino , Seguimentos , Sistema de Condução Cardíaco/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Estudos Retrospectivos , Taquicardia por Reentrada no Nó Atrioventricular/diagnóstico , Taquicardia por Reentrada no Nó Atrioventricular/cirurgia , Taquicardia Supraventricular/classificação , Taquicardia Supraventricular/fisiopatologia , Resultado do Tratamento
5.
Am J Physiol Heart Circ Physiol ; 320(2): H713-H724, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33337966

RESUMO

The complex pathophysiology of atrial fibrillation (AF) is governed by multiple risk factors in ways that are still elusive. Basic electrophysiological properties, including atrial effective refractory period (AERP) and conduction velocity, are major factors determining the susceptibility of the atrial myocardium to AF. Although there is a great need for affordable animal models in this field of research, in vivo rodent studies are limited by technical challenges. Recently, we introduced an implantable system for long-term assessment of AF susceptibility in ambulatory rats. However, technical considerations did not allow us to perform concomitant supraventricular electrophysiology measurements. Here, we designed a novel quadripolar electrode specifically adapted for comprehensive atrial studies in ambulatory rats. Electrodes were fabricated from medical-grade silicone, four platinum-iridium poles, and stainless-steel fixating pins. Initial quality validation was performed ex vivo, followed by implantation in adult rats and repeated electrophysiological studies 1, 4, and 8 wk postimplantation. Capture threshold was stable. Baseline AERP values (38.1 ± 2.3 and 39.5 ± 2.0 using 70-ms and 120-ms S1-S1 cycle lengths, respectively) confirmed the expected absence of rate adaptation in the unanesthetized state and validated our prediction that markedly higher values reported under anesthesia are nonphysiological. Evaluation of AF substrate in parallel with electrophysiological parameters validated our recent finding of a gradual increase in AF susceptibility over time and demonstrated that this phenomenon is associated with an electrical remodeling process characterized by AERP shortening. Our findings indicate that the miniature quadripolar electrode is a potent new tool, which opens a window of opportunities for better utilization of rats in AF research.NEW & NOTEWORTHY Rodents are increasingly used in AF research. However, technical challenges restrict long-term supraventricular electrophysiology studies in these species. Here, we developed an implantable electrode adapted for such studies in the rat. Our findings indicate that this new tool is effective for long-term follow-up of critical parameters such as atrial refractoriness. Obtained data shed light on the normal electrophysiology and on the increased AF susceptibility that develops in rats with implanted atrial electrodes over time.


Assuntos
Fibrilação Atrial/etiologia , Estimulação Cardíaca Artificial , Eletrodos Implantados , Técnicas Eletrofisiológicas Cardíacas/instrumentação , Sistema de Condução Cardíaco/fisiopatologia , Frequência Cardíaca , Monitorização Ambulatorial/instrumentação , Marca-Passo Artificial , Potenciais de Ação , Animais , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/fisiopatologia , Modelos Animais de Doenças , Desenho de Equipamento , Masculino , Valor Preditivo dos Testes , Ratos Sprague-Dawley , Período Refratário Eletrofisiológico , Fatores de Tempo
6.
PLoS One ; 15(12): e0244254, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33347504

RESUMO

Changes in intracellular calcium levels in the sinus node modulate cardiac pacemaking (the calcium clock). Trimeric intracellular cation (TRIC) channels are counterion channels on the surface of the sarcoplasmic reticulum and compensate for calcium release from ryanodine receptors, which play a major role in calcium-induced calcium release (CICR) and the calcium clock. TRIC channels are expected to affect the calcium clock in the sinus node. However, their physiological importance in cardiac rhythm formation remains unclear. We evaluated the importance of TRIC channels on cardiac pacemaking using TRIC-A-null (TRIC-A-/-) as well as TRIC-B+/-mice. Although systolic blood pressure (SBP) was not significantly different between wild-type (WT), TRIC-B+/-, and TRIC-A-/-mice, heart rate (HR) was significantly lower in TRIC-A-/-mice than other lines. Interestingly, HR and SBP showed a positive correlation in WT and TRIC-B+/-mice, while no such correlation was observed in TRIC-A-/-mice, suggesting modification of the blood pressure regulatory system in these mice. Isoproterenol (0.3 mg/kg) increased the HR in WT mice (98.8 ±â€…15.1 bpm), whereas a decreased response in HR was observed in TRIC-A-/-mice (23.8 ±â€…5.8 bpm), suggesting decreased sympathetic responses in TRIC-A-/-mice. Electrocardiography revealed unstable R-R intervals in TRIC-A-/-mice. Furthermore, TRIC-A-/-mice sometimes showed sinus pauses, suggesting a significant role of TRIC-A channels in cardiac pacemaking. In isolated atrium contraction or action potential recording, TRIC-A-/-mice showed decreased response to a ß-adrenergic sympathetic nerve agonist (isoproterenol, 100 nM), indicating decreased sympathetic responses. In summary, TRIC-A-/-mice showed decreased cardiac pacemaking in the sinus node and attenuated responses to ß-adrenergic stimulation, indicating the involvement of TRIC-A channels in cardiac rhythm formation and decreased sympathetic responses.


Assuntos
Potenciais de Ação , Agonistas Adrenérgicos beta/farmacologia , Átrios do Coração/fisiopatologia , Sistema de Condução Cardíaco/fisiopatologia , Canais Iônicos/fisiologia , Retículo Sarcoplasmático/efeitos dos fármacos , Nó Sinoatrial/fisiopatologia , Animais , Átrios do Coração/efeitos dos fármacos , Camundongos , Camundongos Knockout , Nó Sinoatrial/efeitos dos fármacos
7.
Electromagn Biol Med ; 39(4): 433-436, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33016156

RESUMO

To help investigate the relationship between inflammatory and other symptoms of coronavirus and the protein-protein interactions (PPI) that occur between viral proteins and protein molecules of the host cell, I propose that the electrostatic discharge (ESD) exists including corona discharge to lead to ozone gas. I cite evidence in support of this hypothesis. I hope that the proposed will inspire new studies in finding effective treatments and vaccines for individuals with coronavirus disease in 2019. I suggest possible future studies that may lend more credibility to the proposed.


Assuntos
Betacoronavirus/fisiologia , Coronavirus/fisiologia , Modelos Biológicos , Eletricidade Estática , Betacoronavirus/química , Betacoronavirus/patogenicidade , Coronavirus/patogenicidade , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/fisiopatologia , Infecções por Coronavirus/virologia , Sistema de Condução Cardíaco/efeitos dos fármacos , Sistema de Condução Cardíaco/fisiopatologia , Interações entre Hospedeiro e Microrganismos/fisiologia , Humanos , Hidroxicloroquina/farmacologia , Ozônio/metabolismo , Ozônio/toxicidade , Perda de Ozônio , Pandemias , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/fisiopatologia , Pneumonia Viral/virologia , Domínios e Motivos de Interação entre Proteínas/fisiologia , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/fisiologia
8.
Pediatr Clin North Am ; 67(5): 801-810, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32888682

RESUMO

Syncope and palpitations are common complaints for patients presenting to their primary care provider. They represent symptoms that most often have a benign etiology but rarely can be the first warning sign of a serious condition, such as arrhythmias, structural heart disease, or noncardiac disease. The history, physical examination, and noninvasive testing can, in most cases, distinguish benign from pathologic causes. This article introduces syncope and palpitations, with emphasis on the differential diagnoses, initial presentation, diagnostic strategy, and various management strategies.


Assuntos
Arritmias Cardíacas/diagnóstico , Eletrocardiografia , Sistema de Condução Cardíaco/fisiopatologia , Frequência Cardíaca/fisiologia , Síncope/diagnóstico , Arritmias Cardíacas/fisiopatologia , Criança , Diagnóstico Diferencial , Humanos , Síncope/fisiopatologia
11.
Circ Arrhythm Electrophysiol ; 13(8): e007952, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32628863

RESUMO

Artificial intelligence (AI) and machine learning (ML) in medicine are currently areas of intense exploration, showing potential to automate human tasks and even perform tasks beyond human capabilities. Literacy and understanding of AI/ML methods are becoming increasingly important to researchers and clinicians. The first objective of this review is to provide the novice reader with literacy of AI/ML methods and provide a foundation for how one might conduct an ML study. We provide a technical overview of some of the most commonly used terms, techniques, and challenges in AI/ML studies, with reference to recent studies in cardiac electrophysiology to illustrate key points. The second objective of this review is to use examples from recent literature to discuss how AI and ML are changing clinical practice and research in cardiac electrophysiology, with emphasis on disease detection and diagnosis, prediction of patient outcomes, and novel characterization of disease. The final objective is to highlight important considerations and challenges for appropriate validation, adoption, and deployment of AI technologies into clinical practice.


Assuntos
Potenciais de Ação , Arritmias Cardíacas/diagnóstico , Inteligência Artificial , Diagnóstico por Computador , Eletrocardiografia , Técnicas Eletrofisiológicas Cardíacas , Sistema de Condução Cardíaco/fisiopatologia , Frequência Cardíaca , Aprendizado de Máquina , Processamento de Sinais Assistido por Computador , Arritmias Cardíacas/fisiopatologia , Arritmias Cardíacas/terapia , Aprendizado Profundo , Humanos , Valor Preditivo dos Testes , Prognóstico , Reprodutibilidade dos Testes
12.
Int J Cardiovasc Imaging ; 36(11): 2209-2219, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32613382

RESUMO

Chagas' disease (CD), caused by the parasite Trypanosoma cruzi, is the leading cause of cardiac disability from infectious diseases in Central and South America. The disease progresses through an extended, asymptomatic form characterized by latency without clinical manifestations into a symptomatic form with cardiac and gastro-intestinal manifestations. In the terminal phase, chronic Chagas' myocarditis results in extensive myocardial fibrosis, chamber enlargement with aneurysms and ventricular tachycardia (VT). Cardiac magnetic resonance imaging (CMR) has proven useful in characterizing myocardial fibrosis (MF). Sub-epicardial and mid-wall fibrosis are less common patterns of MF in CHD than transmural scar, which resembles myocardial infarction. Commonly involved areas of MF include the left ventricular apex and basal infero-lateral wall, suggesting a role for watershed ischemia in the pathophysiology of MF. Electrophysiology studies have helped refine the relationship between MF and VT in this setting. This article reviews the patterns of MF in CHD and correlate these patterns with electrogram patterns to predict risk of ventricular arrhythmias and sudden death.


Assuntos
Potenciais de Ação , Cardiomiopatia Chagásica/diagnóstico por imagem , Técnicas Eletrofisiológicas Cardíacas , Sistema de Condução Cardíaco/fisiopatologia , Frequência Cardíaca , Imagem por Ressonância Magnética , Miocárdio/patologia , Taquicardia Ventricular/diagnóstico , Cardiomiopatia Chagásica/parasitologia , Cardiomiopatia Chagásica/patologia , Cardiomiopatia Chagásica/fisiopatologia , Progressão da Doença , Fibrose , Sistema de Condução Cardíaco/parasitologia , Humanos , Valor Preditivo dos Testes , Taquicardia Ventricular/parasitologia , Taquicardia Ventricular/fisiopatologia
13.
Ann Epidemiol ; 46: 5-11, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32532371

RESUMO

PURPOSE: Metabolic syndrome has a high prevalence in the United States. P-wave duration is a valuable indicator for atrial electrical conduction. Abnormalities in atrial electrical conduction can predispose to atrial fibrillation. Our objective was to estimate the effect of metabolic syndrome on P-wave duration in a nationally representative sample. METHODS: We included 6499 adults who participated in the National Health and Nutrition Examination Survey III (1988-1994). We estimated the effect of metabolic syndrome and its components on P-wave duration after adjusting for confounders such as demographic and lifestyle variables. We stratified the analyses by gender. RESULTS: Irrespective of gender, participants with metabolic syndrome had a longer P-wave duration than that of those without it. In addition, we observed a positive linear dose-response relation between metabolic syndrome components and P-wave duration. CONCLUSIONS: Patients with metabolic syndrome had a longer P-wave duration. They might have been at a higher risk for atrial fibrillation and mortality; they need to be periodically checked by their health care providers. However, the results of this study should be confirmed in prospective studies.


Assuntos
Eletrocardiografia/métodos , Sistema de Condução Cardíaco/fisiopatologia , Síndrome Metabólica/epidemiologia , Obesidade/epidemiologia , Adulto , Idoso , Fibrilação Atrial/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Síndrome Metabólica/complicações , Síndrome Metabólica/fisiopatologia , Pessoa de Meia-Idade , Inquéritos Nutricionais , Obesidade/complicações , Obesidade/fisiopatologia , Prevalência , Estados Unidos/epidemiologia
14.
Circ Arrhythm Electrophysiol ; 13(7): e008262, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32538133

RESUMO

BACKGROUND: To facilitate ablation of ventricular tachycardia (VT), an automated localization system to identify the site of origin of left ventricular activation in real time using the 12-lead ECG was developed. The objective of this study was to prospectively assess its accuracy. METHODS: The automated site of origin localization system consists of 3 steps: (1) localization of ventricular segment based on population templates, (2) population-based localization within a segment, and (3) patient-specific site localization. Localization error was assessed by the distance between the known reference site and the estimated site. RESULTS: In 19 patients undergoing 21 catheter ablation procedures of scar-related VT, site of origin localization accuracy was estimated using 552 left ventricular endocardial pacing sites pooled together and 25 VT-exit sites identified by contact mapping. For the 25 VT-exit sites, localization error of the population-based localization steps was within 10 mm. Patient-specific site localization achieved accuracy of within 3.5 mm after including up to 11 pacing (training) sites. Using 3 remotes (67.8±17.0 mm from the reference VT-exit site), and then 5 close pacing sites, resulted in localization error of 7.2±4.1 mm for the 25 identified VT-exit sites. In 2 emulated clinical procedure with 2 induced VTs, the site of origin localization system achieved accuracy within 4 mm. CONCLUSIONS: In this prospective validation study, the automated localization system achieved estimated accuracy within 10 mm and could thus provide clinical utility.


Assuntos
Potenciais de Ação , Eletrocardiografia , Sistema de Condução Cardíaco/fisiopatologia , Frequência Cardíaca , Taquicardia Ventricular/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Automação , Ablação por Cateter , Técnicas Eletrofisiológicas Cardíacas , Feminino , Sistema de Condução Cardíaco/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Reprodutibilidade dos Testes , Processamento de Sinais Assistido por Computador , Taquicardia Ventricular/fisiopatologia , Taquicardia Ventricular/cirurgia , Fatores de Tempo
15.
Kardiologiia ; 60(5): 4-8, 2020 May 04.
Artigo em Russo | MEDLINE | ID: mdl-32515698

RESUMO

The beginning of 2020 was characterized by the development of a new coronavirus pandemic (COVID-19). Information about the epidemiology, etiology, pathogenesis, clinical and laboratory diagnostics, as well as prevention and therapy for this disease is constantly being expanded and reviewed. The COVID-19 pandemic creates the need for the emergence of new conditions of specialized care for patients with heart rhythm and conduction disorders [1]. These recommendations are intended for general practitioners, internists, cardiologists, electrophysiologists/arrhythmologists, cardiovascular surgeons, functional diagnostics doctors, anesthesiologists-resuscitators, laboratory diagnostics specialists, health care organizers in the system of organizations and healthcare institutions that provide specialized care to patients with heart rhythm and conduction disorders.


Assuntos
Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/terapia , Doença do Sistema de Condução Cardíaco/diagnóstico , Doença do Sistema de Condução Cardíaco/terapia , Infecções por Coronavirus/epidemiologia , Pneumonia Viral/epidemiologia , Betacoronavirus , Sistema de Condução Cardíaco/fisiopatologia , Humanos , Pandemias
16.
Heart Rhythm ; 17(9): 1434-1438, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32535142

RESUMO

BACKGROUND: Myriad manifestations of cardiovascular involvement have been described in patients with coronavirus disease 2019 (COVID-19), but there have been no reports of COVID-19 affecting the cardiac conduction system. The PR interval on the electrocardiogram (ECG) normally shortens with increasing heart rate (HR). The case of a patient with COVID-19 manifesting Mobitz type 1 atrioventricular (AV) block that normalized as the patient's condition improved prompted us to investigate PR interval behavior in patients with COVID-19. OBJECTIVE: The purpose of this study was to characterize PR interval behavior in hospitalized patients with COVID-19 and to correlate that behavior with clinical outcomes. METHODS: This study was a cross-sectional cohort analysis of confirmed COVID-19 cases (March 26, 2020, to April 25, 2020). We reviewed pre-COVID-19 and COVID-19 ECGs to characterize AV conduction by calculating the PR interval to HR (PR:HR) slope. Clinical endpoints were death or need for endotracheal intubation. RESULTS: ECGs from 75 patients (246 pre-COVID-19 ECGs and 246 COVID-19 ECGs) were analyzed for PR:HR slope. Of these patients, 38 (50.7%) showed the expected PR interval shortening with increasing HR (negative PR:HR slope), whereas 37 (49.3%) showed either no change (8 with PR:HR slope = 0) or paradoxical PR interval prolongation (29 with positive PR:HR slope) with increasing HR. Patients without PR interval shortening were more likely to die (11/37 [29.7%] vs 3/38 [7.9%]; P = .019) or require endotracheal intubation (16/37 [43.2%] vs 8/38 [21.1%]; P = .05) compared to patients with PR interval shortening. CONCLUSION: Half of patients with COVID-19 showed abnormal PR interval behavior (paradoxical prolongation or lack of shortening) with increasing HR. This finding was associated with increased risk of death and need for endotracheal intubation.


Assuntos
Arritmias Cardíacas/epidemiologia , Betacoronavirus , Infecções por Coronavirus/complicações , Infecções por Coronavirus/fisiopatologia , Sistema de Condução Cardíaco/fisiopatologia , Frequência Cardíaca/fisiologia , Pneumonia Viral/complicações , Pneumonia Viral/fisiopatologia , Idoso , Arritmias Cardíacas/diagnóstico , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pandemias , Estudos Retrospectivos
17.
High Blood Press Cardiovasc Prev ; 27(5): 341-347, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32451990

RESUMO

Atrial fibrillation (AF) is the most common cardiac arrhythmia. Pharmacologic and non-pharmacologic rhythm control strategies impact on AF-related symptoms, while leaving largely unaffected the risk of stroke. Moreover, up to 20% of AF patients are asymptomatic during paroxysmal relapses of arrhythmia, thus underlying the need for early markers to identify at-risk patients and prevent cerebrovascular accidents. Indeed, non-invasive assessment of pre-clinical substrate changes that predispose to AF could provide early identification of at-risk patients and allow for tailored care paths. ECG-derived P wave analysis is a simple-to-use and inexpensive tool that has been successfully employed to detect AF-associated structural and functional atrial changes. Beyond standard electrocardiographic techniques, high resolution signal averaged electrocardiography (SAECG), by recording microvolt amplitude atrial signals, allows more accurate analysis of the P wave and possibly AF risk stratification. This review focuses on the evidence that support P wave analysis to assess AF substrates, predict arrhythmia relapses and guide rhythm-control interventions.


Assuntos
Potenciais de Ação , Fibrilação Atrial/diagnóstico , Eletrocardiografia , Sistema de Condução Cardíaco/fisiopatologia , Frequência Cardíaca , Potenciais de Ação/efeitos dos fármacos , Antiarrítmicos/uso terapêutico , Fibrilação Atrial/fisiopatologia , Fibrilação Atrial/terapia , Estimulação Cardíaca Artificial , Ablação por Cateter , Sistema de Condução Cardíaco/cirurgia , Frequência Cardíaca/efeitos dos fármacos , Humanos , Valor Preditivo dos Testes , Recidiva , Processamento de Sinais Assistido por Computador , Fatores de Tempo , Resultado do Tratamento
18.
Ideggyogy Sz ; 73(3-4): 121-127, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-32364339

RESUMO

Background and purpose: To evaluate P-wave dispersion before and after antiepileptic drug (AED) treatment as well as to investigate the risk of ventricular repolarization using the Tpeak-Tend (Tp-e) interval and Tp-e/QT ratio in patients with epileptic disorder. Methods: A total of 63 patients receiving AED therapy and 35 healthy adults were included. ECG recordings were obtained before and 3 months after anti-epileptic treatment among patients with epilepsy. For both groups, Tp-e and Tp-e/QT ratio were measured using a 12-lead ECG device. Results: Tp-e interval, Tpe/QT and Tp-e/QTc ratios were found to be higher in the patient group than in the control group (p<0.05, for all), while QTmax ratio was significantly lower in the patient group. After 3 months of AED therapy, significant increases in QT max, QTc max, QTcd, Tp-e, Tp-e/QT, and Tp-e/QTc were found among the patients (p<0.05). When the arrhythmic effects of the drugs before and after treatment were compared, especially in the valproic acid group, there were significant increases in Tp-e interval, Tp-e/QT and Tp-e/QTc values after three months of treatment (p<0.05). Carbamazepine and levetiracetam groups were not statistically significant in terms of pre- and post-treatment values. Conclusion: It was concluded that an arrhythmogenic environment may be associated with the disease, and patients who received AED monotherapy may need to be followed up more closely for arrhythmia.


Assuntos
Anticonvulsivantes/uso terapêutico , Arritmias Cardíacas/diagnóstico , Carbamazepina/uso terapêutico , Epilepsia/tratamento farmacológico , Sistema de Condução Cardíaco/efeitos dos fármacos , Ventrículos do Coração/efeitos dos fármacos , Levetiracetam/uso terapêutico , Ácido Valproico/uso terapêutico , Adulto , Arritmias Cardíacas/fisiopatologia , Estudos de Casos e Controles , Eletrocardiografia/métodos , Sistema de Condução Cardíaco/fisiopatologia , Ventrículos do Coração/fisiopatologia , Humanos
19.
Circ Arrhythm Electrophysiol ; 13(6): e008186, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32434448

RESUMO

BACKGROUND: Repolarization alternans (RA) has been implicated in the pathogenesis of ventricular arrhythmias and sudden cardiac death. METHODS: We have developed a real-time, closed-loop system to record and analyze RA from multiple intracardiac leads, and deliver dynamically R-wave triggered pacing stimuli during the absolute refractory period. We have evaluated the ability of this system to control RA and reduce arrhythmia susceptibility, in vivo. RESULTS: R-wave triggered pacing can induce RA, the magnitude of which can be modulated by varying the amplitude, pulse width, and size of the pacing vector. Using a swine model (n=9), we demonstrate that to induce a 1 µV change in the alternans voltage on the body surface, coronary sinus and left ventricle leads, requires a delivered charge of 0.04±0.02, 0.05±0.025, and 0.06±0.033 µC, respectively, while to induce a one unit change of the Kscore, requires a delivered charge of 0.93±0.73, 0.32±0.29, and 0.33±0.37 µC, respectively. For all body surface and intracardiac leads, both Δ(alternans voltage) and ΔKscore between baseline and R-wave triggered paced beats increases consistently with an increase in the pacing pulse amplitude, pulse width, and vector spacing. Additionally, we show that the proposed method can be used to suppress spontaneously occurring alternans (n=7), in the presence of myocardial ischemia. Suppression of RA by pacing during the absolute refractory period results in a significant reduction in arrhythmia susceptibility, evidenced by a lower Srank score during programmed ventricular stimulation compared with baseline before ischemia. CONCLUSIONS: We have developed and evaluated a novel closed-loop method to dynamically modulate RA in a swine model. Our data suggest that suppression of RA directly reduces arrhythmia susceptibility and reinforces the concept that RA plays a critical role in the pathophysiology of arrhythmogenesis.


Assuntos
Potenciais de Ação , Arritmias Cardíacas/prevenção & controle , Estimulação Cardíaca Artificial/métodos , Sistema de Condução Cardíaco/fisiopatologia , Período Refratário Eletrofisiológico , Animais , Arritmias Cardíacas/etiologia , Arritmias Cardíacas/fisiopatologia , Modelos Animais de Doenças , Frequência Cardíaca , Isquemia Miocárdica/complicações , Isquemia Miocárdica/fisiopatologia , Sus scrofa , Fatores de Tempo
20.
Circ Arrhythm Electrophysiol ; 13(6): e008733, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32423252

RESUMO

In the past year, there have been numerous advances in our understanding of arrhythmia mechanisms, diagnosis, and new therapies. We have seen advances in basic cardiac electrophysiology with data suggesting that secretoneurin may be a biomarker for patients at risk of ventricular arrhythmias, and we have learned of the potential role of an NPR-C (natriuretic peptide receptor-C) in atrial fibrosis and the role of an atrial specific 2-pore potassium channel TASK-1 as a therapeutic target for atrial fibrillation. We have seen studies demonstrating the role of sensory neurons in sleep apnea-related atrial fibrillation and the association between bariatric surgery and atrial fibrillation ablation outcomes. Artificial intelligence applied to electrocardiography has yielded estimates of age, sex, and overall health. We have seen new tools for collection of patient-centered outcomes following catheter ablation. There have been significant advances in the ability to identify ventricular tachycardia termination sites through high-density mapping of deceleration zones. We have learned that right ventricular dysfunction may be a predictor of survival benefit after implantable cardioverter-defibrillator implantation in patients with nonischemic cardiomyopathy. We have seen further insights into the role of His bundle pacing on improving outcomes. As our understanding of cardiac laminopathies advances, we may have new tools to predict arrhythmic event rates in gene carriers. Finally, we have seen numerous advances in the treatment of arrhythmias in patients with congenital heart disease.


Assuntos
Arritmias Cardíacas , Sistema de Condução Cardíaco , Potenciais de Ação , Animais , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/mortalidade , Arritmias Cardíacas/fisiopatologia , Arritmias Cardíacas/terapia , Estimulação Cardíaca Artificial , Ablação por Cateter , Criocirurgia , Desfibriladores Implantáveis , Cardioversão Elétrica/instrumentação , Eletrocardiografia , Técnicas Eletrofisiológicas Cardíacas , Predisposição Genética para Doença , Sistema de Condução Cardíaco/fisiopatologia , Sistema de Condução Cardíaco/cirurgia , Frequência Cardíaca , Humanos , Marca-Passo Artificial , Fatores de Risco , Resultado do Tratamento
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