Progressão da Lesão Miocárdica após Ablação por Radiofrequência em Crianças em Idade Escolar / Myocardial Injury Progression after Radiofrequency Ablation in School-Age Children

Resumo Fundamento As últimas décadas têm assistido ao rápido desenvolvimento do tratamento invasivo de arritmias por procedimentos de ablação por cateter. Apesar da sua segurança e eficácia bem estabelecida em adultos, até o momento, há poucos dados nos cenários pediátricos. Uma das principais preocupações é a possível expansão da cicatriz do procedimento de ablação nessa população e suas consequências ao longo dos anos. Objetivos Este estudo teve como objetivo analisar o risco da progressão da lesão miocárdica após ablação por cateter de radiofrequência em pacientes pediátricos. Métodos Este é um estudo retrospectivo de 20 pacientes pediátricos com tratamento prévio de arritmia supraventricular com ablação, submetidos à ressonância magnética cardíaca e angiografia coronária para avaliação de fibrose miocárdica e da integridade das artérias coronárias durante o acompanhamento. Resultados A idade mediana no procedimento de ablação foi 15,1 anos (Q1 12,9, Q3 16,6) e 21 anos (Q1 20, Q3 23) quando a ressonância magnética cardíaca foi realizada. Quatorze dos pacientes eram mulheres. Taquicardia por reentrada nodal e síndrome de Wolf-Parkinson-White foram os principais diagnósticos (19 pacientes), com um paciente com taquicardia atrial. Três pacientes apresentaram fibrose miocárdica ventricular, mas com um volume inferior a 0,6 cm 3 . Nenhum deles desenvolveu disfunção ventricular e nenhum paciente apresentou lesões coronarianos na angiografia. Conclusão A ablação por cateter de radiofrequência não mostrou aumentar o risco de progressão de lesão miocárdica ou de lesões na artéria coronária.

Abstract Background The past decades have seen the rapid development of the invasive treatment of arrhythmias by catheter ablation procedures. Despite its safety and efficacy being well-established in adults, to date there has been little data in pediatric scenarios. One of the main concerns is the possible expansion of the ablation procedure scar in this population and its consequences over the years. Objectives This study aimed to analyze the risk of myocardial injury progression after radiofrequency catheter ablation in pediatric patients. Methods This is a retrospective study of 20 pediatric patients with previous ablation for treatment of supraventricular arrhythmia that underwent cardiac magnetic resonance and coronary angiography for evaluation of myocardial fibrosis and the integrity of the coronary arteries during follow-up. Results The median age at ablation procedure was 15.1 years (Q1 12.9, Q3 16.6) and 21 years (Q1 20, Q3 23) when the cardiac magnetic resonance was performed. Fourteen of them were women. Nodal reentry tachycardia and Wolf-Parkinson-White Syndrome were the main diagnosis (19 patients), with one patient with atrial tachycardia. Three patients had ventricular myocardial fibrosis, but with a volume < 0.6 cm 3 . None of them developed ventricular dysfunction and no patient had coronary lesions on angiography. Conclusion Radiofrequency catheter ablation did not show to increase the risk of myocardial injury progression or coronary artery lesions.

Favorable Safety Experience of Local Dental Anesthesia in ICD Recipients with Cardiac Channelopathies

Abstract Background Dental anesthetic management in implantable cardioverter defibrillator (ICD) recipients with cardiac channelopathies (CCh) can be challenging due to the potential risk of life-threatening arrhythmias and appropriate ICD therapies during procedural time. Objectives The present study assessed the hypothesis that the use of local dental anesthesia with 2% lidocaine with 1:100,000 epinephrine or without a vasoconstrictor can be safe in selected ICD and CCh patients, not resulting in life-threatening events (LTE). Methods Restorative dental treatment under local dental anesthesia was made in two sessions, with a wash-out period of 7 days (cross-over trial), conducting with a 28h - Holter monitoring, and 12-lead electrocardiography, digital sphygmomanometry, and anxiety scale assessments in 3 time periods. Statistical analysis carried out the paired Student's t test and the Wilcoxon signed-rank test. In all cases, a significance level of 5% was adopted. All patients were in stable condition with no recent events before dental care. Results Twenty-four consecutive procedures were performed in 12 patients (9 women, 3 men) with CCh and ICD: 7 (58.3%) had long QT syndrome (LQTS), 4 (33.3%) Brugada syndrome (BrS), and 1 (8.3%) Catecholaminergic polymorphic ventricular tachycardia (CPVT). Holter analysis showed no increased heart rate (HR) or sustained arrhythmias. Blood pressure (BP), electrocardiographic changes and anxiety measurement showed no statistically significant differences. No LTE occurred during dental treatment, regardless of the type of anesthesia. Conclusion Lidocaine administration, with or without epinephrine, can be safely used in selected CCh-ICD patients without LTE. These preliminary findings need to be confirmed in a larger population with ICD and CCh.

Trombo Atrial Esquerdo e Contraste Espontâneo Denso no Uso de Anticoagulante Oral de Ação Direta em Fibrilação Atrial: Visão de Centro Referenciado / Left Atrial Thrombus and Dense Spontaneous Contrast in Direct Oral Anticoagulant Therapy of Atrial Fibrillation: Insights from a Reference Center

Resumo Fundamento No tratamento da fibrilação atrial (FA), a arritmia sustentada mais frequente, com ablação por cateter (ABL) ou cardioversão elétrica (CVE), o período periprocedimento é uma das fases mais críticas. Atualmente, o uso de novos anticoagulantes orais de ação direta (DOAC) é cada vez mais frequente, no entanto, no mundo real, ainda existem poucos dados de estudos sobre a incidência de trombo no átrio esquerdo (TrAE) ou contraste espontâneo denso (CE) no ecocardiograma transesofágico (ETE). Objetivo Analisar a prevalência de TrAE, por ETE, em pacientes em uso de DOAC submetidos à CVE/ABL. Secundariamente: avaliar a associação de comorbidades com a presença de trombos e CE. Métodos Estudo de coorte retrospectivo, unicêntrico, com pacientes do Ambulatório de Arritmia (InCor-HCFMUSP). Foram selecionados e analisados dados clínicos e ecocardiográficos no prontuário da instituição de pacientes com indicação de procedimentos e em uso de DOACs. Considerado um nível de significância de 5%. Resultados Foram incluídos 354 pacientes, no total de 400 procedimentos, de março de 2012-março de 2018. TrAE foi encontrado em 11 pacientes (2,8%), associado com idade avançada (p=0,007) e CHA2DS2-VASc maior (p<0,001). Foi encontrado CE no AE no procedimento antes da ETE em 29 pacientes (7,3%), com menor FEVE (p <0,038) e maior dimensão do AE (p <0,0001). Conclusão A incidência de TrAE e CE em pacientes em uso de DOAC no contexto de CVE/ABL de FA, embora pequena, não é desprezível. Pacientes com escore CHA2DS2-VASc maior, principalmente mais idosos e com diâmetro do AE maior, são mais propensos a esses achados ecocardiográficos.

Abstract Background In the treatment of atrial fibrillation (AF), the most frequently sustained arrhythmia, with catheter ablation (CA) or electrical cardioversion (ECV), the periprocedural period is one of the most critical phases. Currently, the use of new direct action oral anticoagulants (DOAC) is increasingly frequent; however, in the real world, there are still few data on studies on the thrombus incidence in the left atrium (TrLA) or dense spontaneous contrast (DSC) on transesophageal echocardiogram (TEE). Objective To evaluate the prevalence of events and association with risk factors in patients using DOACs. Primary objective: to analyze the prevalence of thrombus in the LA by TEE in patients using DOAC undergoing ECV/CA. Second, evaluate the association of comorbidities with the presence of thrombi and DSC. Methods Retrospective cohort, single-center study with patients followed at the Arrhythmia Outpatient Unit (InCor-HCFMUSP). Patients indicated for procedures and using DOACs were selected, and their clinical/echocardiographic data were analyzed. A significance level of 5% was considered. Results 354 patients were included, a total of 400 procedures, from March 2012-March 2018. Thrombus in the LA was found in 11 patients (2.8%), associated with advanced age (p=0.007) and higher CHA2DS2-VASc (p<0.001) score. DSC in the LA before TEE was found in 29 patients (7.3%), with lower LVEF (p<0.038) and greater LA dimension (p<0.0001). Conclusion The incidence of LA thrombus and DSC in patients using DOC in the context of AF ECV/CA, although small, is not negligible. Patients with higher CHA2DS2-VASc scores, especially older and with larger LA diameter, are more prone to these echocardiographic findings.

Arterial stiffness and atrial fibrillation: A review

ABSTRACT Arterial stiffness has been investigated as part of the physiopathology of arterial hypertension since the 1970s. Its role in increasing the "pulsatile load" imposed over the Left Ventricle (LV) has been intensely studied recently and has helped in understanding the mechanisms of Atrial Fibrillation (AF) in hypertensive patients. This paper aims to review the main evidence on this issue and establish possible mechanisms involved in the development of AF in patients with arterial stiffness. A PubMed search was performed, and selected articles were searched for references focusing on this topic. In the long term, lower blood pressure levels allow for arterial wall remodeling, leading to a lower stiffness index. To this day, however, there are no available treatments that directly promote the lowering of arterial wall stiffness. Most classes of anti-hypertensive drugs ‒ with stronger evidence for beta-blockers and diuretics ‒ could be effective in reducing arterial stiffness. There is strong evidence demonstrating an association between arterial stiffness and AF. New studies focusing on arterial stiffness and pre-fibrillatory stages would strengthen this causality relation.

Prognosis of chronic Chagas heart disease and other pending clinical challenges

In this chapter, the main prognostic markers of Chagas heart disease are addressed, with an emphasis on the most recent findings and questions, establishing the basis for a broad discussion of recommendations and new approaches to managing Chagas cardiopathy. The main biological and genetic markers and the contribution of the electrocardiogram, echocardiogram and cardiac magnetic resonance are presented. We also discuss the most recent therapeutic proposals for heart failure, thromboembolism and arrhythmias, as well as current experience in heart transplantation in patients suffering from severe Chagas cardiomyopathy. The clinical and epidemiological challenges introduced by acute Chagas disease due to oral contamination are discussed. In addition, we highlight the importance of ageing and comorbidities in influencing the outcome of chronic Chagas heart disease. Finally, we discuss the importance of public policies, the vital role of funding agencies, universities, the scientific community and health professionals, and the application of new technologies in finding solutions for better management of Chagas heart disease.

A Remodelação do Sistema Nervoso Autônomo Cardíaco pode Desempenhar um Papel na Fibrilação Atrial: Um Estudo do Sistema Nervoso Autônomo e Receptores Miocárdicos / Cardiac Autonomic Nervous System Remodeling May Play a Role in Atrial Fibrillation: A Study of the Autonomic Nervous System and Myocardial Receptors

Resumo Fundamento Alterações do substrato elétrico e anatômico do coração são fatores que originam e perpetuam a fibrilação atrial (FA), porém, os mecanismos envolvidos não foram totalmente elucidados ainda. Objetivo: Avaliar o papel do remodelamento do sistema nervoso cardíaco intrínseco (SNCI), incluindo fibras nervosas e receptores muscarínicos e β-adrenérgicos, na FA permanente humana. Métodos Foram avaliadas 4 amostras em átrios de 13 corações obtidos em necrópsias de pacientes com doença cardíaca e FA permanente, e em 13 controles com as mesmas doenças, porém, sem FA. Utilizando imunoperoxidase e histomorfometria, quantificamos a densidade das fibras do SNCI, bem como a porcentagem positiva de miocárdio para receptores β-adrenérgicos 1, 2 e 3, receptor quinase 5 acoplado à proteína G (GRK-5), e receptores muscarínicos 1 a 5. Os resultados foram comparados usando ANOVA e ANOVA hierarquizada e ajustados pelo volume do átrio esquerdo e, para avaliação da expressão de receptores β e GRK-5, pelo uso de β-bloqueadores. Adotamos como significativo α = 0,05. Resultados Houve aumento na densidade das fibras ( p <0,01), especialmente nas fibras simpáticas ( p =0,02). Quanto aos receptores muscarínicos, só houve diferença nos M1, que estavam aumentados (5,87±4,52 vs 2,85±2,40; p =0,03). Quanto aos componentes do sistema adrenérgicos analisados, houve expressão aumentada de β-3 (37,41 vs 34,18, p =0,04) e GRK-5 (51,16 vs 47,66; p<0,01). O uso de β-bloqueadores não teve impacto na expressão de receptores beta. Conclusão O aumento na inervação do SNCI e a alteração na expressão de receptores em regiões suscetíveis de desencadear FA podem ter um papel na fibrilação atrial permanente.

Abstract Background The primary factors that originate and perpetuate atrial fibrillation (AF) are electrical and anatomical substrate alterations. However, the central mechanisms governing AF perpetuation have not been elucidated yet, which is reflected on the modest results of the treatment in patients with long persistent AF. Objective To evaluate if human intrinsic cardiac autonomic nervous system (ICANS) remodeling, including nervous system fibers and muscarinic and β-adrenergic receptors, play a role in permanent AF. Methods Heart necropsy samples from thirteen patients with heart disease and permanent AF and thirteen controls without AF were used. By using immunoperoxidase and histomorphometry quantification, we identified the following: the density of all fibers of the ICANS, sympathetic and parasympathetic fibers; and the percentage of myocardium positive for β-adrenergic receptors 1, 2 and 3; G protein-coupled receptor kinase-5 (GRK-5); and muscarinic receptors M1 to M5. The results were compared using ANOVA and nested ANOVA and were adjusted according to the left atrium volume for all variables, and β-blocker use to evaluate the expression of β-receptors and GRK-5. Results There was an overall increase in the density of fibers of the ICANS (p=0.006), especially in atrial sympathetic nerve fibers (p=0.017). Only M1 muscarinic receptors were increased (5.87 vs 2.35, p=0.032). For adrenergic receptors, the results were positive for increased expression of β-3 (37.41 vs 34.18, p=0.039) and GRK-5 (51.16 vs 47.66; p<0.001). β-blocker use had no impact on β-receptor expression. Conclusion Increased ICANS innervation and remodeling receptor expression in regions prone to triggering AF may play a role in permanent AF.

Tireotoxicose induzida pela amiodarona - revisão de literatura e atualização clínica / Amiodarone-induced thyrotoxicosis - literature review & clinical update

Resumo A amiodarona é amplamente utilizada no tratamento de arritmias atriais e ventriculares, porém devido sua alta concentração de iodo, o uso crônico da droga pode induzir distúrbios tireoidianos. A tireotoxicose induzida pela amiodarona (TIA) pode descompensar e exacerbar anormalidades cardíacas subjacentes, provocando aumento da morbidade e mortalidade, principalmente em pacientes com fração de ejeção do ventrículo esquerdo <30%. Os casos de TIA são classificados em dois subtipos que direcionam a conduta terapêutica. Os riscos e benefícios de manter a amiodarona devem ser avaliados de maneira individualizada, e a decisão de continuar ou suspender a droga deve ser tomada conjuntamente por cardiologistas e endocrinologistas. O tratamento de TIA tipo 1 é semelhante ao do hipertireoidismo espontâneo, sendo indicado o uso de drogas antitireoidianas (metimazol e propiltiouracil) em doses elevadas. A TIA tipo 1 mostra-se mais complicada, pois apresenta proporcionalmente maiores números de recorrências ou até mesmo a não remissão do quadro, sendo recomendado o tratamento definitivo (tireoidectomia total ou radioiodo). TIA tipo 2 é geralmente autolimitada, mas devido a elevada mortalidade associada a tireotoxicose em pacientes cardiopatas, o tratamento deve ser instituído para que o eutireoidismo seja atingido mais rapidamente. Em casos bem definidos de TIA tipo 2, o tratamento com corticosteroides é mais efetivo do que o tratamento com drogas antitireoidianas. Em casos graves, independentemente do subtipo, a restauração imediata do eutiroidismo por meio da tireoidectomia total deve ser considerada antes que o paciente evolua com piora clínica excessiva, pois a demora na indicação da cirurgia está associada ao aumento da mortalidade.

Abstract Amiodarone is widely used in treating atrial and ventricular arrhythmias; however, due to its high iodine concentration, the chronic use of the drug can induce thyroid disorders. Amiodarone-induced thyrotoxicosis (AIT) can decompensate and exacerbate underlying cardiac abnormalities, leading to increased morbidity and mortality, especially in patients with left ventricular ejection fraction <30%. AIT cases are classified into two subtypes that guide therapeutic management. The risks and benefits of maintaining the amiodarone must be evaluated individually, and the therapeutic decision should be taken jointly by cardiologists and endocrinologists. Type 1 AIT treatment is similar to that of spontaneous hyperthyroidism, using antithyroid drugs (methimazole and propylthiouracil) at high doses. Type 1 AIT is more complicated since it has proportionally higher recurrences or even non-remission, and definitive treatment is recommended (total thyroidectomy or radioiodine). Type 2 AIT is generally self-limited, yet due to the high mortality associated with thyrotoxicosis in cardiac patients, the treatment should be implemented for faster achievement of euthyroidism. Furthermore, in well-defined cases of type 2 AIT, the treatment with corticosteroids is more effective than treatment with antithyroid drugs. In severe cases, regardless of subtype, immediate restoration of euthyroidism through total thyroidectomy should be considered before the patient progresses to excessive clinical deterioration, as delayed surgery indication is associated with increased mortality.

Catheter Ablation in Neonate with Heart Failure Due to Incessant Atrioventricular Reentrant Tachycardia

Abstract The atrioventricular (AV) reentrant tachycardia (AVRT) is the most common cause of supraventricular tachycardia (SVT) in the young pediatric population. Some newborns might present with congestive heart failure and require interventional treatment. Catheter ablation in small infants (<6 months and <5 kg) is still poorly performed and controversial due to high complications rate in this group of patients.1 We report a case of a 28 days old infant (3,5 kg) with a drug-refractory left accessory pathway mediated tachycardia and severe hemodynamic compromise, who underwent catheter ablation. Radiofrequency ablation should be part of the therapeutic arsenal in a context of drug-resistant supraventricular tachycardia with hemodynamic compromise, despite the greater risks of complications in this special population.

Peculiaridade dos pacientes com arritmias hereditárias na pandemia pela COVID-19 / Peculiar aspects of patients with Inherited arrhythmias during the COVID-19 pandemic

Resumo Desde dezembro de 2019, observamos o rápido avanço da síndrome respiratória aguda grave causada pelo coronavírus 2019 (SARS-CoV-2). O impacto da evolução clínica de uma infecção respiratória é pouco conhecido em pacientes portadores de arritmias hereditárias, devido à baixa prevalência dessas doenças. Os pacientes que apresentam quadros infecciosos podem exacerbar arritmias primárias ocultas ou bem controladas, por diversos fatores, tais como febre, distúrbios eletrolíticos, interações medicamentosas, estresse adrenérgico e, eventualmente, o próprio dano miocárdico do paciente séptico. O objetivo desta revisão é destacar os principais desafios que podemos encontrar durante a pandemia pela Covid 19, especificamente nos pacientes com arritmias hereditárias, com destaque para a síndrome do QT longo congênito (SQTL), a síndrome de Brugada (SBr), a taquicardia ventricular polimórfica catecolaminérgica (TVPC) e a cardiomiopatia arritmogênica do ventrículo direito.

Abstract Since December 2019 we have observed the rapid advance of the severe acute respiratory syndrome caused by the new coronavirus (SARS-CoV-2). The impact of the clinical course of a respiratory infection is little known in patients with hereditary arrhythmias, due to the low prevalence of these diseases. Patients who present with infectious conditions may exacerbate hidden or well-controlled primary arrhythmias, due to several factors, such as fever, electrolyte disturbances, drug interactions, adrenergic stress and, eventually, the septic patient's own myocardial damage. The aim of this review is to highlight the main challenges we may encounter during the Covid 19 pandemic, specifically in patients with hereditary arrhythmias, with emphasis on the congenital long QT syndrome (LQTS), Brugada syndrome (SBr), ventricular tachycardia polymorphic catecholaminergic (CPVT) and arrhythmogenic right ventricular cardiomyopathy.