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Introduction: The echocardiographic diagnosis criteria for arrhythmogenic right ventricular cardiomyopathy (ARVC) are highly specific but sensitivity is low, especially in the early stages of the disease. The role of echocardiographic strain in ARVC has not been fully elucidated, although prior studies suggest that it can improve the detection of subtle functional abnormalities. The purposes of the study were to determine whether these advanced measures of right ventricular (RV) dysfunction on echocardiogram, including RV strain, increase diagnostic value for ARVC disease detection and to evaluate the association of echocardiographic parameters with arrhythmic outcomes. Methods: The study included 28 patients from the Heart Institute of São Paulo ARVC cohort with a definite diagnosis of ARVC established according to the 2010 Task Force Criteria. All patients were submitted to ECHO’s advanced techniques including RV strain, and the parameters were compared to prior conventional visual ECHO and CMR. Results: In total, 28 patients were enrolled in order to perform ECHO’s advanced techniques. A total of 2/28 (7%) patients died due to a cardiovascular cause, 2/28 (7%) underwent heart transplantation, and 14/28 (50%) patients developed sustained ventricular arrhythmic events. Among ECHO’s parameters, RV dilatation, measured by RVDd (p = 0.018) and RVOT PSAX (p = 0.044), was significantly associated with arrhythmic outcomes. RV free wall longitudinal strain < 14.35% in absolute value was associated with arrhythmic outcomes (p = 0.033). Conclusion: Our data suggest that ECHO’s advanced techniques improve ARVC detection and that abnormal RV strain can be associated with arrhythmic risk stratification. Further studies are necessary to better demonstrate these findings and contribute to risk stratification in ARVC, in addition to other well-known risk markers.

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.

Acute and subacute cardiotoxicity are characterized by prolongation of the corrected QT interval (QTc) and other measures derived from the QTc interval, such as QTc dispersion (QTdc) and transmural dispersion of repolarization (DTpTe). Although anthracyclines prolong the QTc interval, it is unclear whether breast cancer patients who undergo the ACT chemotherapy regimen of anthracycline (doxorubicin: A), cyclophosphamide (C) and taxane (T) may present with QTc, QTdc and DTpTe prolongation.Twenty-three consecutive patients with breast cancer were followed prospectively during ACT chemotherapy and were analyzed according to their QT measurements. QTc, QTdc and DTpTe measurements were determined by a 12-lead electrocardiogram (EKG) prior to chemotherapy (baseline), immediately after the first phase of anthracycline and cyclophosphamide (AC) treatment, and immediately after T treatment. Serum troponin and B-type natriuretic peptide (BNP) levels were also measured.Compared to baseline values, the QTc interval was significantly prolonged after the AC phase (439.7 ± 33.2 ms vs. 472.5 ± 36.3 ms, p = 0.001) and after T treatment (439.7 ± 33.2 ms vs. 467.9 ± 42.6 ms, p < 0.001). Troponin levels were elevated after the AC phase (23.0 pg/mL [min-max: 6.0-85.0] vs. 6.0 pg/mL [min-max: 6.0-22.0], p < 0.001) and after T treatment (25.0 pg/mL [min-max: 6.0-80.0] vs. 6.0 pg/mL [min-max: 6.0-22.0], p < 0.001) compared to baseline values.In this prospective study of patients with non-metastatic breast cancer who underwent ACT chemotherapy, significant QTc prolongation and an elevation in serum troponin levels were observed.

Background: Sudden death is the leading cause of death in Chagas disease (CD), even in patients with preserved ejection fraction (EF), suggesting that destabilizing factors of the arrhythmogenic substrate (autonomic modulation) contribute to its occurrence. Objective: To determine baroreflex sensitivity (BRS) in patients with undetermined CD (GI), arrhythmogenic CD with nonsustained ventricular tachycardia (NSVT) (GII) and CD with spontaneous sustained ventricular tachycardia (STV) (GIII), to evaluate its association with the occurrence and complexity of arrhythmias. Method: Forty-two patients with CD underwent ECG and continuous and noninvasive BP monitoring (TASK force monitor). The following were determined: BRS (phenylephrine method); heart rate variability (HRV) on 24-h Holter; and EF (echocardiogram). Results: GIII had lower BRS (6.09 ms/mm Hg) as compared to GII (11.84) and GI (15.23). The difference was significant between GI and GIII (p = 0.01). Correlating BRS with the density of ventricular extrasystoles (VE), low VE density ( 10/h) had preserved BRS (p = 0.003). Patients with depressed BRS had higher VE density (p = 0.01), regardless of the EF. The BRS was the only variable related to the occurrence of SVT (p = 0.028). Conclusion: The BRS is preserved in undetermined CD. The BRS impairment increases as disease progresses, being more severe in patients with more complex ventricular arrhythmias. The degree of autonomic dysfunction did not correlate with EF, but with the density and complexity of ventricular arrhythmias.

FUNDAMENTO: A utilização de anestésicos locais associados a vasoconstritores para tratamento odontológico de rotina de pacientes cardiopatas ainda gera controvérsia, em razão do risco de efeitos cardiovasculares adversos. OBJETIVO: Avaliar e comparar os efeitos hemodinâmicos do uso de anestésico local com vasoconstritor não-adrenérgico em pacientes portadores de arritmias ventriculares, em relação ao uso de anestésico sem vasoconstritor. MÉTODOS: Um estudo prospectivo randomizado avaliou 33 pacientes com sorologia positiva para doença de Chagas' e 32 pacientes com doença arterial coronariana, portadores de arritmia ventricular complexa ao Holter (>10 EV/h e TVNS), 21 do sexo feminino, idade de 54,73 + 7,94 anos, submetidos a tratamento odontológico de rotina com anestesia pterigomandibular. Esses pacientes foram divididos em dois grupos: no grupo I, utilizou-se prilocaína a 3% associada a felipressina 0,03 UI/ml, e no grupo II, lidocaína a 2% sem vasoconstritor. Avaliaram-se o número e a complexidade de extra-sístoles, a freqüência cardíaca e a pressão arterial sistêmica dos pacientes no dia anterior, uma hora antes, durante o procedimento odontológico e uma hora após. RESULTADOS: Não foram observadas alterações hemodinâmicas, nem aumento do número e da complexidade da arritmia ventricular, relacionados ao anestésico utilizado, em ambos os grupos. CONCLUSÃO: Os resultados sugerem que prilocaína a 3% associada a felipressina 0,03 UI/ml pode ser utilizada com segurança em pacientes chagásicos e coronarianos, com arritmia ventricular complexa.BACKGROUND: The routine use of local anesthetics associated to vasoconstrictors for the dental treatment of patients with cardiopathies is still controversial, due to the risk of adverse cardiovascular effects. OBJECTIVE: To evaluate and compare the hemodynamic effects of the use of local anesthetics with a non-adrenergic vasoconstrictor in patients with ventricular arrhythmia, when compared to the use of anesthetics without vasoconstrictor. METHODS: A prospective randomized study evaluated 33 patients with positive serology for Chagas' disease and 32 patients with coronary artery disease that presented complex ventricular arrhythmia at Holter monitoring (>10 EV/h and NSVT), of which 21 were females, aged 54.73 + 7.94 years, submitted to routine dental treatment with pterygomandibular anesthesia. These patients were divided in two groups: group I received prilocaine 3% associated with felypressin 0.03 IU/ml and group II received lidocaine 2% without vasoconstrictor. The number and complexity of extrasystoles were analyzed, as well as the heart rate and systemic arterial pressure of the patients on the day before, one hour before, during the procedure and one hour after the dental procedure. RESULTS: No hemodynamic alterations or increase in the number and complexity of the ventricular arrhythmia related to the anesthetic used in the dental procedure were observed in either group. CONCLUSION: The results suggest that prilocaine 3% associated to a felypressin 0.03 IU/ml can be safely used in patients with Chagas' disease or coronariopathy with complex ventricular arrhythmia.

OBJETIVO: Estudar a prevalência de síncope neurocardiogênica em pacientes com síncope inexplicada e extra-sístoles ventriculares (EV), com morfologia de via de saída de ventrículo direito (VSVD) sem cardiopatia estrutural aparente. MÉTODOS: Noventa pacientes (66 mulheres, idade média de 40,2 ± 16,95 anos) com EV monomórficas com origem na VSVD foram avaliados prospectivamente. Cinqüenta e quatro pacientes apresentavam síncopes ou pré-síncopes associadas ou não a palpitações; 27 apresentavam palpitações sem pré-síncope ou síncope, e 9 eram assintomáticos. Todos foram submetidos a ecocardiograma, ECG de alta resolução, ressonância magnética cardíaca e teste de esforço para afastar cardiopatia estrutural e taquicardia ventricular adrenérgico-dependente, e a monitorização com Holter e monitor de eventos sintomáticos para correlacionar os sintomas com a arritmia. A investigação de suscetibilidade a síncope neurocardiogênica foi avaliada pelo teste de inclinação (TI). Os grupos foram comparados quanto a sexo, idade, freqüência e complexidade das extra-sístoles, com e sem esforço físico, resultado do TI e evolução clínica. RESULTADOS: No grupo com síncope e pré-síncope, o TI foi positivo em 38% dos casos e nos grupos com palpitações e assintomáticos, em 11% (p = 0,0257). Após orientação e tratamento da síncope neurocardiogênica, 85% dos pacientes com síncope e pré-sincope e TI positivo permaneceram assintomáticos durante seguimento médio de 40 meses. Dois pacientes com síncope e TI negativos apresentaram taquicardia ventricular sustentada espontânea durante a evolução clínica. CONCLUSÃO: A prevalência de síncope neurocardiogênica em pacientes com EV idiopáticas de VSVD é alta. Pacientes com síncope recorrente inexplicada e EV idiopáticas devem ser mantidos sob investigação.OBJECTIVE: Study the prevalence of neurocardiogenic etiology in patients with unexplained syncope and ventricular premature beats, with right ventricle outflow tract morphology (RVOT) and no apparent structural cardiopathy. METHODS: Ninety patients (66 women, mean age 40.2±16.95 years of age) with monomorphic premature beats originated at RVOT were evaluated prospectively. Fifty-four patients reported syncopes or near-syncopes associated to palpitations or not; twenty-seven presented palpitations with no pre-syncope or syncope, and nine were asymptomatic. All patients were submitted to echocardiogram, high resolution ECG and cardiac MRI to rule out structural cardiopathy, to exertion test to rule out adrenergic dependent ventricular tachycardia, and ECG prolonged outpatient monitoring (Holter and symptomatic events monitor) to correlate symptoms and ventricular arrhythmias. Investigation on the susceptibility to neurocardiogenic syncope was evaluated by Tilt Table Test (TTT). Groups were compared regarding gender, age, premature beats frequency and complexity, at exertion or not, TTT results and clinical course. RESULTS: In the syncope and pre-syncope groups, TTT was positive for 38% of cases, and in groups with palpitations and assymptomatics, it was positive for 11% (p = 0.0257). After recommendations and treatment of neurocardiogenic syncope, 85% of syncope and pre-syncope patients and positive TTT was asymptomatic along the 40-month follow-up. Two patients with syncope and negative TTT presented spontaneous, sustained ventricular tachycardia during clinic course. CONCLUSION: The prevalence of neurocardiogenic syncope in patients with idiopathic RVOT premature beats is high. Patients with recurrent, unexplained syncope and idiopathic VE must be kept under investigation.

Abstract Compound heterozygosity has been described in inherited arrhythmias, and usually associated with a more severe phenotype. Reports of this occurrence in Brugada syndrome patients are still rare. We report a study of genotype-phenotype correlation after the identification of new variants by genetic testing. We describe the case of an affected child with a combination of two different likely pathogenic SCN5A variants, presenting sinus node dysfunction, flutter and atrial fibrillation, prolonged HV interval, spontaneous type 1 Brugada pattern in the prepubescent age and familiar history of sudden death.

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 Emotional distress is related to recurrence of syncope compromising patient's quality of life (QoL). The aim of this study was to determine if weekly sessions of psychotherapy reduce recurrence of events and improve QoL by SF-36 among patients with refractory vasovagal syncope. A randomised controlled pilot trial including 10 patients with recurrent vasovagal syncope and positive tilt table test was conducted. Known cardiac disease and ongoing psychotherapeutic interventions were the main exclusion criteria. All patients received standard of care treatment. Additionally, after randomisation, half of the patients underwent weekly sessions of psychotherapy for 12 months. Analysis of recurrence of events and QoL showed no significant change in the control group but, in the intervention group, there was a significant reduction in the rate of near-syncope episodes per month (5.7 ± 1.4 × 1.7 ± 1.0; P

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

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

ObjectiveMutations in the Lamin A/C(LMNA) gene are commonly associated with cardiac manifestations, such as dilated cardiomyopathy (DCM) and conduction system disease. However, the overall spectrum and penetrance of rare LMNA variants are unknown. The present study described the presence of LMNAvariants in patients with “lone atrial fibrillation (AF)” as their sole clinical presentation.MethodsOne-hundred and one consecutive patients with “lone AF” criteria were initially screened by genetic testing. Genetic variants were classified according to the American College of Genetic and Genomic criteria. All subjects were evaluated through clinical and familial history, ECG, 24-h Holter monitoring, echocardiogram, cardiac magnetic resonance, treatment response, and the present relatives of LMNA carriers. In addition, whole-exome data from 49,960 UK Biobank (UKB) participants were analyzed to describe the overall penetrance of rare LMNA missense and loss of function (LOF) variants.ResultsThree missense variants in LMNA were identified in probands with AF as their first and unique clinical manifestation. Other five first-degree relatives, after the screening, also presented LMNA gene variants. Among 49,960 analyzed UKB participants, 331 carried rare LMNA missense or LOF variant. Participants who carried a rare LMNA variant were significantly associated with higher odds of arrhythmic events and of an abnormal ECG in the per-protocol ECG exam (p = 0.03 and p = 0.05, respectively).ConclusionAlthough a rare occurrence, our findings emphasize the possibility of an initial presentation of apparently “lone AF” in LMNA gene variant carriers.

BackgroundWarfarin is the most common oral anticoagulant drug, especially in low-income and emerging countries, because of the high cost of direct oral anticoagulant (DOACs), or when warfarin is the only proven therapy (mechanical prosthetic valve and kidney dysfunction). The quality of warfarin therapy is directly associated with dose management. Evidence shows that pharmaceutical care achieves a better quality of therapy with warfarin. However, there are no studies showing this intervention in a specific patient group with poor quality of anticoagulation in a long period after the end of the follow-up by a pharmacist. Thus, the aim of this study was to evaluate whether the quality of warfarin therapy driven by a pharmacist remains stable in the long term after the end of follow up with a pharmacist, in AF patients with poor quality of anticoagulation.MethodsThis is a prospective study, which evaluated about 2,620 patients and selected 262 patients with AF and poor quality of anticoagulation therapy with warfarin (TTR

Background Brugada syndrome and long‐QT syndrome may account for at least one third of unexplained sudden cardiac deaths. Dental care in patients with cardiac channelopathies is challenging because of the potential risk of life‐threatening events. We hypothesized that the use of local dental anesthesia with lidocaine with and without epinephrine is safe and does not result in life‐threatening arrhythmias in patients with channelopathies. Methods and Results We performed a randomized, double‐blind pilot trial comparing the use of 2% lidocaine without a vasoconstrictor and with 1:100 000 epinephrine in 2 sessions of restorative dental treatment with a washout period of 7 days (crossover trial). Twenty‐eight–hour Holter monitoring was performed, and 12‐lead electrocardiography, digital sphygmomanometry, and anxiety scale assessments were also conducted at 3 time points. Fifty‐six dental procedures were performed in 28 patients (18 women, 10 men) with cardiac channelopathies: 16 (57.1%) had long‐QT syndrome, and 12 (42.9%) had Brugada syndrome; 11 (39.3%) of patients had an implantable defibrillator. The mean age was 45.9±15.9 years. The maximum heart rate increased after the use of epinephrine during the anesthesia period from 82.1 to 85.8 beats per minute (P=0.008). In patients with long‐QT syndrome, the median corrected QT was higher, from 450.1 to 465.4 ms (P=0.009) at the end of anesthesia in patients in whom epinephrine was used. The other measurements showed no statistically significant differences. No life‐threatening arrhythmias occurred during dental treatment. Conclusions The use of local dental anesthesia with lidocaine, regardless of the use of a vasoconstrictor, did not result in life‐threatening arrhythmias and appears to be safe in stable patients with cardiac channelopathies. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT03182777.

Thromboembolic events are associated with high mortality and morbidity indexes. In this context, warfarin is the most widely prescribed oral anticoagulant agent for preventing and treating these events. This medication has a narrow therapeutic range and, consequently, patients usually have difficulty in achieving and maintaining stable target therapeutics. Some studies on the literature about oral anticoagulant management showed that pharmacists could improve the efficiency of anticoagulant therapy. However, the majority of these studies included general patients retrospectively. The aim of this study was to prospectively evaluate a pharmacist’s warfarin management in patients with poor quality of anticoagulation therapy (Time in the Therapeutic Range- TTR < 50%). We included 268 patients with atrial fibrillation (AF) and without stable dose of warfarin (TTR < 50%, based on the last three values of International Normalized Ratio-INR). We followed them up for 12 weeks, INR values were evaluated and, when necessary, the dose adjustments were performed. During the first four visits, patient’s INR was measured every 7 days. Then, if INR was within the target therapeutic range (INR: 2–3), the patient was asked to return in 30 days. However, if INR was out the therapeutic target, the patient was asked to return in 7 days. Adherence evaluation was measured through questionnaires and by counting the pills taken. Comparison between basal TTR (which was calculated based on the three last INR values before prospective phase) and TTR of 4 weeks (calculated by considering the INR tests from visits 0 to 4, in the prospective phase of the study) and basal TTR and TTR of 12 weeks (calculated based on the INR tests from visits 0 to 12, in the prospective phase of the study) revealed significant statistical differences (0.144 ± 0.010 vs. 0.382 ± 0.016; and 0.144 ± 0.010 vs. 0.543 ± 0.014, p < 0.001, respectively). We also observed that the mean TTR of 1 year before (retrospective phase) was lower than TTR value after 12 weeks of pharmacist-driven treatment (prospective phase) (0.320 ± 0.015; 0.540 ± 0.015, p < 0.001). In conclusion, pharmaceutical care was able to improve TTR values in patients with AF and poor quality of anticoagulation with warfarin.

FUNDAMENTO: Ablação por radiofrequência (ARF) em crianças consiste em uma prática cada vez mais frequente. OBJETIVO: Avaliar, em nossa instituição, os resultados da ARF em crianças com idade abaixo de 15 anos. MÉTODOS: Foram analisadas 125 crianças submetidas à ARF entre maio de 1991 a maio de 2010. RESULTADOS: Sessenta e sete (53,6%) crianças eram do sexo masculino, com idade entre 44 dias e 15 anos (média de 8,6 ± 3,3 anos) e peso mediano de 31 kg. Cardiopatia esteve presente em 21 (16,8%) pacientes. A ARF de vias acessórias (VA) foi o procedimento mais comum (62 crianças - 49,6%). A ARF de taquicardias por reentrada nodal (TRN) foi a segunda arritmia mais frequente, em 27 (21,6%), seguida de taquicardias atriais (TA), em 16 (12,8%) e de taquicardias ventriculares (TV) em 8 (6,4%) crianças. Os critérios de sucesso foram alcançados em 86,9%, 96,1%, 80% e 62,5% dos pacientes submetidos à ARF de VA, TRN, TA e TV, respectivamente. Os bloqueios atrioventriculares transitórios (BAVT) ocorreram durante a ARF em 4 (3,2%) e BRD em 7 (5,6%) crianças. Vinte e cinco crianças foram submetidos à nova ARF por insucesso inicial ou recorrência. Durante o seguimento médio de 5,5 ± 3,4 anos, 107 (88,4%) persistiram sem recorrência. Não houve diferença estatística em relação aos resultados e à idade em que o paciente se submeteu ao procedimento. Nenhuma criança apresentou BAVT persistente ou necessitou de marca-passo definitivo. CONCLUSÃO: A ablação por cateter é uma alternativa terapêutica segura e eficiente em crianças com taquicardias recorrentes refratárias ao tratamento clínico.BACKGROUND: Radiofrequency ablation (RFA) in children is an increasingly common practice. OBJECTIVE: To evaluate, in our institution, the results of RFA in children younger than 15 years. METHODS: A total of 125 children submitted to RFA between May 1991 and May 2010 were analyzed. RESULTS: Sixty-seven (53.6%) children were males, aged between 44 days and 15 years (mean 8.6 ± 3.3 years) with median weight of 31 kg. Heart disease was present in 21 (16.8%) patients. The RFA of accessory pathways (AP) was the most common procedure (62 children - 49.6%). The RFA of nodal reentrant tachycardia (NRT) was the second most common arrhythmia in 27 (21.6%), followed by atrial tachycardia (AT) in 16 (12.8%) and ventricular tachycardias (VT) in 8 (6.4%) children. The success criteria were achieved in 86.9%, 96.1%, 80% and 62.5% of patients undergoing RFA of AP, NRT, AT and VT, respectively. Transient AVB occurred during RFA in 4 (3.2%) and LBBB in 7 (5.6%) children. Twenty-five children underwent a new RFA due to initial failure or recurrence. During the mean follow up of 5.5 ± 3.4 years, 107 (88.4%) remained without recurrence. There was no statistical difference regarding the results and the age at which the patient underwent the procedure. No child had persistent AVB or required a permanent pacemaker. CONCLUSION: Catheter ablation is a safe and effective alternative therapy in children with recurrent tachycardias refractory to medical treatment.

FUNDAMENTO: A maioria dos trabalhos tem descrito preditores de recorrência de fibrilação atrial após ablação por cateter, com tempos de seguimento relativamente curtos. OBJETIVO: Avaliar retrospectivamente, em longo prazo, os preditores de recorrência de fibrilação atrial paroxística (FA) em pacientes submetidos ao isolamento das veias pulmonares, após um único procedimento. MÉTODOS: Foram estudados 139 pacientes (102 homens com idade média de 55 ± 12 anos) submetidos à ablação por radiofreqüência, por meio das técnicas ostial ou extra-ostial de abordagem do átrio esquerdo, associadas ou não à ablação do istmo cavo-tricuspídeo (ICT). Variáveis pré, intra e pós-ablação foram avaliadas por análise uni e multivariada, para determinar os preditores de recorrência da FA após um procedimento. RESULTADOS: Após um seguimento de 33 ± 12 meses, observou-se que maior tempo de história de FA, uso de mais antiarrítmicos e recorrência de FA num período de sessenta dias pós-procedimento aumentaram o risco de recorrência de FA em longo prazo. Por sua vez, a associação de flutter atrial e a ablação concomitante do ICT reduziram o risco de recorrência. CONCLUSÃO: Variáveis clínicas como tempo de história de FA e maior quantidade de antiarrítmicos já utilizadas influenciam os resultados da ablação por cateter. Em pacientes com flutter atrial associado, a realização concomitante de linha de bloqueio no ICT reduziu significativamente a recorrência de fibrilação atrial em longo prazo.BACKGROUND: Most of the studies on this subject have reported predictors of recurrence of atrial fibrillation after catheter ablation with relatively short follow-up periods. OBJECTIVE: To retrospectively evaluate predictors of long-term recurrence of paroxysmal atrial fibrillation (AF) in patients undergoing pulmonary vein isolation following one single procedure. METHODS: The authors studied a total of 139 patients (102 men; mean age of 55 ± 12 years) undergoing radiofrequency ablation using the ostial or extra-ostial techniques for left atrial approach, combined or not with cavotricuspid isthmus ablation (CTI). Pre, intra and post-ablation variables were evaluated using univariate and multivariate analyses to determine the predictors of recurrence of AF after one procedure. RESULTS: After a 33 ± 12-month follow-up, we observed that a longer time of history of AF, use of more antiarrhythmic drugs, and recurrence of AF within 60 days post-procedure increased the risk of long-term recurrence of AF. On the other hand, the association of atrial flutter and concomitant CTI ablation reduced the risk of recurrence of AF. CONCLUSION: Clinical variables such as time of history of AF and a larger number of antiarrhythmic drugs already used influenced the outcomes of catheter ablation. In patients with associated atrial flutter, simultaneous CTI block significantly reduced the long-term recurrence of atrial fibrillation.

OBJETIVO: Determinar a efetividade do isolamento cirúrgico da parede posterior do átrio esquerdo envolvendo os óstios das veias pulmonares, no tratamento da fibrilação atrial de etiologia reumática. MÉTODOS: Estudo prospectivo e randomizado envolvendo portadores de valvopatia mitral reumática, fibrilação atrial persistente com duração > a 6 meses, idade < a 60 anos e diâmetro atrial esquerdo < a 65 mm. Os pacientes foram distribuídos aleatoriamente em dois grupos: tratamento cirúrgico valvar (grupo controle) e tratamento cirúrgico valvar associado ao isolamento da parede posterior do átrio esquerdo mediante técnica de "corte e sutura" (grupo tratado). RESULTADOS: Foram operados 29 indivíduos, sendo que 27 (13 do grupo controle e 14 do grupo tratado), foram acompanhados regularmente. Os pacientes dos dois grupos não diferiram em relação às suas características basais. O tempo de seguimento médio foi de 11,5 meses no grupo controle e de 10,3 meses no grupo tratado. As freqüências cumulativas de pacientes livres de fibrilação atrial foram significativamente maiores no grupo tratado tanto na fase peri-operatória (p= 0,0035) quanto na fase tardia (p= 0,0430). CONCLUSÃO: O isolamento cirúrgico da parede posterior do átrio esquerdo envolvendo os óstios das veias pulmonares é uma forma efetiva de tratamento da fibrilação atrial na valvopatia mitral reumática.OBJECTIVE: To determine the effectiveness of surgical isolation of the left atrial posterior wall encompassing the ostia of the pulmonary veins for the treatment of atrial fibrillation of rheumatic etiology. METHODS: Prospective and randomized study of patients with rheumatic mitral valve disease, persistent atrial fibrillation for 6 months or longer, age < 60 years, and left atrial diameter < 65 mm. The patients were randomly distributed into 2 groups as follows: surgical valvular treatment (control group) and surgical valvular treatment associated with isolation of the left atrial posterior wall according to the "cut-and-sew" technique (treated group). RESULTS: Twenty-nine individuals were operated upon, 27 of whom (13 in the control group and 14 in the treated group) were regularly followed up. The patients of both groups did not differ in regard to their basal characteristics. The mean follow-up time was 11.5 months in the control group and 10.3 months in the treated group. The cumulative frequencies of the patients without atrial fibrillation were significantly greater in the treated group both in the perioperative (P=0.0035) and late (P=0.0430) phases. CONCLUSION: Surgical isolation of the left atrial posterior wall encompassing the ostia of the pulmonary veins is an effective form of treating atrial fibrillation in rheumatic mitral valve disease.

AbstractBackground:Cardiac resynchronization therapy (CRT) is the recommended treatment by leading global guidelines. However, 30%-40% of selected patients are non-responders.Objective:To develop an echocardiographic model to predict cardiac death or transplantation (Tx) 1 year after CRT.Method:Observational, prospective study, with the inclusion of 116 patients, aged 64.89 ± 11.18 years, 69.8% male, 68,1% in NYHA FC III and 31,9% in FC IV, 71.55% with left bundle-branch block, and median ejection fraction (EF) of 29%. Evaluations were made in the pre‑implantation period and 6-12 months after that, and correlated with cardiac mortality/Tx at the end of follow-up. Cox and logistic regression analyses were performed with ROC and Kaplan-Meier curves. The model was internally validated by bootstrapping.Results:There were 29 (25%) deaths/Tx during follow-up of 34.09 ± 17.9 months. Cardiac mortality/Tx was 16.3%. In the multivariate Cox model, EF < 30%, grade III/IV diastolic dysfunction and grade III mitral regurgitation at 6‑12 months were independently related to increased cardiac mortality or Tx, with hazard ratios of 3.1, 4.63 and 7.11, respectively. The area under the ROC curve was 0.78.Conclusion:EF lower than 30%, severe diastolic dysfunction and severe mitral regurgitation indicate poor prognosis 1 year after CRT. The combination of two of those variables indicate the need for other treatment options.

Abstract Background: 30-40% of cardiac resynchronization therapy cases do not achieve favorable outcomes. Objective: This study aimed to develop predictive models for the combined endpoint of cardiac death and transplantation (Tx) at different stages of cardiac resynchronization therapy (CRT). Methods: Prospective observational study of 116 patients aged 64.8 ± 11.1 years, 68.1% of whom had functional class (FC) III and 31.9% had ambulatory class IV. Clinical, electrocardiographic and echocardiographic variables were assessed by using Cox regression and Kaplan-Meier curves. Results: The cardiac mortality/Tx rate was 16.3% during the follow-up period of 34.0 ± 17.9 months. Prior to implantation, right ventricular dysfunction (RVD), ejection fraction < 25% and use of high doses of diuretics (HDD) increased the risk of cardiac death and Tx by 3.9-, 4.8-, and 5.9-fold, respectively. In the first year after CRT, RVD, HDD and hospitalization due to congestive heart failure increased the risk of death at hazard ratios of 3.5, 5.3, and 12.5, respectively. In the second year after CRT, RVD and FC III/IV were significant risk factors of mortality in the multivariate Cox model. The accuracy rates of the models were 84.6% at preimplantation, 93% in the first year after CRT, and 90.5% in the second year after CRT. The models were validated by bootstrapping. Conclusion: We developed predictive models of cardiac death and Tx at different stages of CRT based on the analysis of simple and easily obtainable clinical and echocardiographic variables. The models showed good accuracy and adjustment, were validated internally, and are useful in the selection, monitoring and counseling of patients indicated for CRT.

Sao raríssimos os casos descritos na literatura de miocardiopatia dilatada (MD) comprovadamente induzida por taquicardia ventricular (TV) incessante (