Renal denervation for the treatment of ventricular arrhythmias: A systematic review and meta-analysis.

INTRODUCTION: Ventricular arrhythmias (VAs) are a major cause of morbidity and mortality in patients with heart disease. Recent studies evaluated the effect of renal denervation (RDN) on the occurrence of VAs. We conducted a systematic review and meta-analysis to determine the efficacy and safety of this procedure. METHODS AND RESULTS: A systematic search of the literature was performed to identify studies that evaluated the use of RDN for the management of VAs. Primary outcomes were reduction in the number of VAs and implantable cardioverter-defibrillator (ICD) therapies. Secondary outcomes were changes in blood pressure and renal function. Ten studies (152 patients) were included in the meta-analysis. RDN was associated with a reduction in the number of VAs, antitachycardia pacing, ICD shocks, and overall ICD therapies of 3.53 events/patient/month (95% confidence interval [CI] = -5.48 to -1.57), 2.86 events/patient/month (95% CI = -4.09 to -1.63), 2.04 events/patient/month (95% CI = -2.12 to -1.97), and 2.68 events/patient/month (95% CI = -3.58 to -1.78), respectively. Periprocedural adverse events occurred in 1.23% of patients and no significant changes were seen in blood pressure or renal function. CONCLUSIONS: In patients with refractory VAs, RDN was associated with a reduction in the number of VAs and ICD therapies, and was shown to be a safe procedure.

Predictive role of Selvester QRS score in patients undergoing transcatheter aortic valve replacement.

INTRODUCTION: Few data exist regarding the late clinical impact of the Selvester score prediction of myocardial fibrosis after transcatheter aortic valve replacement (TAVR). This study evaluated the predictive power of the Selvester score on survival in patients with aortic stenosis (AS) undergoing TAVR. METHODS AND RESULTS: Patients with severe AS who had preoperative electrocardiograms were included. Clinical follow-up was obtained retrospectively. The primary endpoint was all-cause mortality. Secondary endpoints were cardiovascular death and major adverse cardiac events (MACEs). Two-hundred twenty-eight patients were included (mean age, 81.5 ± 7.4 years; women, 58.3%). Deceased patients had a higher mean score (4.6 ± 3.2 vs. 1.4 ± 1.3; p < .001). At a mean follow-up of 36.2 ± 21.2 months, the Selvester score was independently associated with all-cause mortality (hazard ratio [HR], 1.65; 95% confidence interval [CI], 1.48-1.84; p < .001), cardiovascular death (HR, 1.59; 95% CI, 1.38-1.74; p < .001), and MACE (HR, 1.55; 95% CI, 1.30-1.68; p < .001). After 5 years, the mortality risk was incrementally related to the Selvester score. The involvement of the inferior wall of the left ventricle was a lower mortality risk factor (HR, 0.42; 95% CI, 0.18-0.98; p = .046). For a Selvester score of 3, the area under the curve showed 0.92, 0.94, and 0.86 (p < .001), respectively, for 1, 2, and 3 years. CONCLUSIONS: Elevated Selvester scores increase the risk of poor outcomes in patients with AS undergoing TAVR. The involvement of the anterior or lateral wall presents worse prognosis.

Effects of swimming exercise on the extinction of fear memory in rats.

We investigated the relation between swimming exercise and fear memory extinction. Rats that performed regular swimming exercise over 6 wk underwent fear conditioning. Twenty-eight days later, they were submitted to extinction tests. Swimming rats had enhanced extinction process throughout the 5 days of the extinction test compared with sedentary rats. This suggests that the swimming exercise accelerated the process of aversive memory extinction, reducing the expression of conditioned fear behavior. These results encourage further studies addressing the anxiolytic effects of exercise, with potential implications for anxiety disorders such as posttraumatic stress disorder. NEW & NOTEWORTHY We have shown that rats that performed regular swimming exercise over 6 wk had enhanced extinction process compared with sedentary animals. The swimming exercise may accelerate the process of aversive memory extinction, reducing the expression of conditioned fear behavior.

Analysis of Circulating miR-1, miR-23a, and miR-26a in Atrial Fibrillation Patients Undergoing Coronary Bypass Artery Grafting Surgery.

Atrial fibrillation (AF) is the most common arrhythmia after cardiac surgery. From a pathophysiological point of view, a myriad of factors such as trauma, atrial dilation, ischemia, mechanical myopericarditis, autonomic imbalance, loss of connexins, AF nest remodeling, inflammation, sutures, and dysfunction caused by postextracorporeal circulation can contribute to postoperative atrial fibrillation (POAF) resulting in a longer hospital stay and consequently higher cost. Recent studies showed that short fragments of RNA, called microRNA (miRNA), can contribute to the development of several cardiovascular diseases, including AF. The aim of this study was to evaluate the levels of circulating miRNAs (miR-1, -23a, and -26a) that can be involved in POAF. Patients submitted to coronary artery bypass graft surgery were grouped in POAF (24 patients) and without POAF (24 patients). Results showed older age, longer clamp-time, and more days in the intensive care unit as well as a longer total hospital stay in the POAF group. Preoperative levels of circulating miRNAs were similar. Analysis of miRNAs revealed significantly lower circulating levels of miRNA-23a (P = 0.02) and -26a (P = 0.01) in the POAF group during the postoperative period. Receiver operating characteristic (ROC) analysis showed the area under the ROC curve of miR-23a and miR-26a for predicting FA was 0.63 (95% confidence interval [CI]: 0.51-0.74; P = 0.02) and 0.66 (95% CI: 0.55-0.77; P = 0.01), respectively. Our data suggests that circulating miRNA-23a and -26a may be involved in the underlying biology of postoperative AF development.

A rare case of Ganglioneuroblastoma Encapsulated in Pheochromocytoma.

Pheochromocytoma and Ganglioneuroblastoma are separate diseases and a rare combination in which the diagnosis can only be confirmed by pathological examination after tumor excision. We reported here a case of ganglioneuroblastoma encapsulated in pheochromocytoma. The patient is a woman, 73 years old, hypertensive, with hypothyroidism, associated for 15 years with hypercholesterolemia and hypertriglyceridemia, which had frequent complaints of low back pain. She underwent magnetic resonance and the findings were consistent with the diagnosis of pheochromocytoma. After surgery, anatomic, pathologic and immunohistochemistry analysis confirmed the diagnosis of pheochromocytoma composed by small ganglioneuroblastoma representation with the identification of small focus of infiltration of the adrenal capsule and adipose tissue by pheochromocytoma. This rare association can instigate the discussion of methods of diagnosis, more effective and more appropriate treatments for each patient.

Electrophysiological study in chagasics with syncope and conduction disorder.

BACKGROUND: Investigation of syncope involves the use of electrophysiological study, particularly in patients with cardiac conduction disorder. There is conflicting evidence about the role of electrophysiological study in patients with Chagas disease. OBJECTIVE: The objective of this study was to evaluate the electrophysiological study findings in patients with Chagas disease and bundle branch block and/or divisional block presenting with syncope. METHODS: This is a retrospective study of patients with Chagas disease and cardiac conduction disorder who underwent electrophysiological study from 2017 to 2021 for the investigation of syncope in a tertiary hospital in São Paulo, Brazil. Those with non-interpretable ECG, known coronary artery disease, and/or other cardiomyopathies were excluded. HV interval and electrophysiological study-induced malignant ventricular arrhythmias data were analyzed. RESULTS: A total of 45 patients (60.2±11.29 years, 57.8% males) were included. The mean HV interval was 58.37 ms±10.68; 22.2% of the studied population presented an HV interval of ≥70 ms; and malignant ventricular arrhythmias were induced in 57.8% patients. The use of beta-blockers and amiodarone (p=0.002 and 0.036, respectively), NYHA functional class≥II (p=0.013), wide QRS (p=0.047), increased HV interval (p=0.02), Rassi score >6.5 (p=0.003), and reduced left ventricular ejection fraction (p=0.031) were associated with increased risk of inducible malignant ventricular arrhythmias. CONCLUSION: More than half of the patients with Chagas disease, syncope, and cardiac conduction disorder have inducible malignant ventricular arrhythmias. Prolonged HV interval was observed in only 20% of population. Wide QRS, prolonged HV, reduced ejection fraction, and higher Rassi score were associated with increased risk of malignant ventricular arrhythmias.

The accuracy of the Stroke Risk Analysis (SRA) system for predicting atrial fibrillation in patients in the postoperative period of myocardial revascularization.

INTRODUCTION: Postoperative myocardial revascularization atrial fibrillation (POAF) is a clinical complication that affects about 30% of patients and its mechanisms of origin are still poorly understood. This fact makes it difficult to identify the patient at greatest risk for this arrhythmia. This mission seems evident due to the complications it entails, including longer hospital stays, risk of stroke, heart failure, and death. There are reports of preoperative clinical aspects inherent to the patient's condition, such as gender and age, and discontinuation of beta-blockers as risk factors. In addition, additional information obtained by electrocardiogram, echocardiogram, and blood count data, for example, present only modest predictive results. The analysis of heart rate and heart rate variability obtained by the Stroke Risk Analysis System (SRA) is a technique used to predict ambulatory atrial fibrillation (AF), using recordings of only one hour showing good accuracy. This system, however, has not yet been used to predict the emergence of POAF. The rationale for its use is based on the suspicion that the emergence of POAF is strongly related to sympatho-vagal imbalance and the increase in atrial ectopia, that is, changes in heart rhythm, the main variables analyzed by the SRA algorithm. OBJECTIVE: To assess the accuracy of the SRA to identify patients at risk of having POAF after coronary artery bypass graft surgery (CABG). METHOD: 114 consecutive patients with coronary artery disease underwent coronary artery bypass grafting between the years 2015 and 2018. Between the first and fifth postoperative days, they underwent continuous electrocardiographic monitoring using the Holter system for cardiac rhythm analysis. Patients were divided into two groups: Group I was formed of those with POAF and Group II included patients without POAF. The tracings obtained by Holter were reanalyzed using the CardioManager®/Cardios program, converted and divided into one-hour sections using the SRA®/Cardios and Geratherm Converter program and submitted to the SRA-Apoplex medical/Geratherm® analysis algorithm. The SRA identifies three possibilities for classifying patient risk: a) Risk 0: patient in sinus rhythm; b) Risk 1: patient at increased risk for paroxysmal AF; c) Risk 2: patient with AF already present. For Group I, SRA were considered positive when Risks 1 and 2 were identified. For Group II, those identified as Risk 0 were considered negative SRA. RESULTS: POAF occurred in 33/114 patients (28%). The sensitivity, specificity, positive predictive value, and negative predictive value of the SRA to identify patients with POAF were 69%, 84%, 69%, and 82%, respectively; the positive and negative likelihood ratios, in addition to the accuracy of the SRA were, respectively, 4.3%, 0.36%, and 79%. A subanalysis of the results of the day on which AF occurred was performed on the records obtained in the first three hours of recording and up to three hours before the appearance of POAF. In the first period, the SRA was able to predict POAF in 57% of cases, while in the second period, the system identified the arrhythmia in 83% of cases. CONCLUSIONS: a) The SRA presents good accuracy to predict POAF; b) its accuracy is moderate in the first three hours of recording; c) the accuracy increases significantly near the beginning of POAF; d) these findings indicate that electrophysiological changes that precede POAF are acute, occurring a few hours before the event and are identified by the SRA algorithm.

CHA2DS2-VASc score, P-wave indexes, and echocardiographic parameters in sinus rhythm patients without valvular heart disease.

OBJECTIVE: The aim of this study was to evaluate the correlation between P-wave indexes, echocardiographic parameters, and CHA2DS2-VASc score in patients without atrial fibrillation and valvular disease. METHODS: This retrospective cross-sectional study included patients of a tertiary hospital with no history of atrial fibrillation, atrial flutter, or valve disease and collected data from June 2021 to May 2022. The exclusion criteria were as follows: unavailable medical records, pacemaker carriers, absence of echocardiogram report, or uninterpretable ECG. Clinical, electrocardiographic [i.e., P-wave duration, amplitude, dispersion, variability, maximum, minimum, and P-wave voltage in lead I, Morris index, PR interval, P/PR ratio, and P-wave peak time], and echocardiographic data [i.e., left atrium and left ventricle size, left ventricle ejection fraction, left ventricle mass, and left ventricle indexed mass] from 272 patients were analyzed. RESULTS: PR interval (RHO=0.13, p=0.032), left atrium (RHO=0.301, p<0.001) and left ventricle diameter (RHO=0.197, p=0.001), left ventricle mass (RHO=0.261, p<0.001), and left ventricle indexed mass (RHO=0.340, p<0.001) were positively associated with CHA2DS2-VASc score, whereas P-wave amplitude (RHO=-0.141, p=0.02), P-wave voltage in lead I (RHO=-0.191, p=0.002), and left ventricle ejection fraction (RHO=-0.344, p<0.001) were negatively associated with the same score. The presence of the Morris index was associated with high CHA2DS2-VASc (p=0.022). CONCLUSION: Prolonged PR interval, Morris index, increased left atrium diameter, left ventricle diameter, left ventricle mass, and left ventricle indexed mass values as well as lower P-wave amplitude, P-wave voltage in lead I, and left ventricle ejection fraction values were correlated with higher CHA2DS2-VASc scores.

F Wave Amplitude as a Predictor of Thromboembolism and Success of Electrical Cardioversion in Patients with Persistent Atrial Fibrillation. / Amplitude das Ondas F como Preditor de Tromboembolismo e de Sucesso da Cardioversão Elétrica em Pacientes com Fibrilação Atrial Persistente.

BACKGROUND: Atrial fibrillation (AF) is classified according to the amplitude of fibrillatory waves (f) into fine waves (fAF) and coarse waves (cAF). OBJECTIVES: To correlate the amplitude of f waves with clinical, laboratory, electrocardiographic, and echocardiographic variables that indicate a high risk of thromboembolism and to assess their impact on the success of electrical cardioversion (ECV). METHODS: Retrospective, observational study that included 57 patients with persistent non-valvular AF who underwent ECV. The maximum amplitude of f waves was measured in lead V1. cAF was defined when f ≥ 1.0mm and fAF when f < 1.0mm. The findings were correlated with the indicated variables. Values of p < 0.05 were considered statistically significant. RESULTS: cAF (n = 35) was associated with greater success in ECV (94.3% vs. 72.7%, p = 0.036) even after adjusting for variables such as age and BMI (p = 0.026, OR = 11.8). Patients with fAF (n = 22) required more shocks and more energy to revert to sinus rhythm (p = 0.019 and p = 0.027, respectively). There was no significant association between f-wave amplitude and clinical, echocardiographic, and laboratory parameters. CONCLUSIONS: The amplitude of f wave was not associated with echocardiographic, clinical and laboratory parameters that indicate a high risk of thromboembolism. cAF was associated with a higher chance of success reverting to sinus rhythm employing ECV. A greater number of shocks and energy were required for reversion to sinus rhythm in patients with fAF.

FUNDAMENTO: A fibrilação atrial (FA) é classificada, de acordo com a amplitude das ondas fibrilatórias (f), em ondas finas (FAf) e ondas grossas (FAg). OBJETIVOS: Correlacionar a amplitude das ondas f com variáveis clínicas, laboratoriais, eletrocardiográficas e ecocardiográficas que indiquem alto risco de tromboembolismo e avaliar o seu impacto no sucesso da cardioversão elétrica (CVE). MÉTODOS: Estudo retrospectivo, observacional, que incluiu 57 pacientes com FA não valvar persistente submetidos a CVE. A amplitude máxima das ondas f foi aferida na derivação V1. FAg foi definida quando f≥1,0 mm e FAf quando f<1,0mm. Os achados foram correlacionados com as variáveis indicadas. Valores de p<0,05 foram considerados estatisticamente significativos. RESULTADOS: FAg (n=35) associou-se a maior sucesso na CVE (94,3% vs. 72,7%, p=0,036) mesmo após ajuste para variáveis como idade e IMC (p=0,026, OR=11,8). Pacientes com FAf (n=22) necessitaram mais choques e maior energia para reversão ao ritmo sinusal (p=0,019 e p=0,027, respectivamente). Não houve associação significativa entre a amplitude das ondas f e parâmetros clínicos, ecocardiográficos e laboratoriais. CONCLUSÕES: A amplitude de f não se associou a parâmetros ecocardiográficos, clínicos e laboratoriais que indicam alto risco de tromboembolismo. FAg associou-se a maior chance de sucesso na reversão ao ritmo sinusal por meio da CVE. Maior número de choques e energia foram necessários para reversão ao ritmo sinusal em pacientes com FAf.

Influence of antidepressant drugs on DNA methylation of ion channels genes in blood cells of psychiatric patients.

Aim: This study investigated the influence of antidepressant drugs on methylation status of KCNE1, KCNH2 and SCN5A promoters and ECG parameters in adult psychiatric patients. Materials & methods: Electrocardiographic evaluation (24 h) and blood samples were obtained from 34 psychiatric patients before and after 30 days of antidepressant therapy. Methylation of promoter CpG sites of KCNE1, KCNH2 and SCN5A was analyzed by pyrosequencing. Results: Three CpG and four CpG sites of KCNE1 and SCN5A, respectively, had increased % methylation after treatment. Principal component analysis showed correlations of the methylation status with electrocardiographic variables, antidepressant doses and patient age. Conclusion: Short-term treatment with antidepressant drugs increase DNA methylation in KCNE1 and SCN5A promoters, which may induce ECG alterations in psychiatric patients.

Relationship between ventricular repolarization parameters and the inducibility of ventricular arrhythmias during electrophysiological study in patients with coronary artery disease.

OBJECTIVE: Risk stratification of sudden cardiac death in patients with coronary artery disease is of great importance. We evaluated the association between ventricular repolarization and induction of malignant ventricular arrhythmias on electrophysiological study of patients with coronary artery disease. METHODS AND RESULTS: A total of 177 patients (65±10.1 years, 83.6% male, mean left ventricular ejection fraction [LVEF] 37.5±13.6%) were analyzed. For each 10 ms increment in the QT interval, there was a 7% increase in malignant ventricular arrhythmias inducibility; QT cutoff point of 452 ms had an accuracy of 0.611 for predicting malignant ventricular arrhythmias (p=0.011). Male gender (odds ratio [OR]=4.18, p=0.012), LVEF <35% (OR=2.32, p=0.013), amiodarone use (OR=2.01, p=0.038), and prolonged QT (OR=1.07, p=0.023) were associated with malignant ventricular arrhythmias. In patients with ventricular dysfunction, QT >452 ms was associated with significantly increased risk of malignant ventricular arrhythmias (OR=5.44, p=0.0004). In those with LVEF ³35%, QT dispersion (QTd) was significantly higher in patients with inducible malignant ventricular arrhythmias. QTd >20 ms had 0.638 accuracy and 81.3% negative predictive value in predicting malignant ventricular arrhythmias. CONCLUSION: QT interval is an independent factor associated with malignant ventricular arrhythmias in patients with coronary artery disease. The combination of ventricular dysfunction and prolonged QT interval is associated with a 5.44-fold increase of malignant ventricular arrhythmias induction. Male gender, amiodarone use, and decreased left ventricular ejection fraction are also associated with increased risk of inducibility of malignant ventricular arrhythmias on the electrophysiological study.

Septal Ablation with Radiofrequency Catheters Guided by Echocardiography for Treatment of Patients with Obstructive Hypertrophic Cardiomyopathy: Initial Experience. / Ablação Septal com Cateteres e Radiofrequência Guiada pela Ecocardiografia para Tratamento de Pacientes com Cardiomiopatia Hipertrófica Obstrutiva: Experiência Inicial.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) can cause obstruction in the left ventricular outflow tract (LVOT), and be responsible for the onset of limiting symptoms, such as tiredness. When such symptoms are refractory to pharmacological treatment, interventionist alternative therapies can be useful, such as septal ablation through the infusion of alcohol in the coronary artery or through myectomy. Recently, the use of a radiofrequency (RF) catheter for endocardial septal ablation guided by electroanatomic mapping has proven to be efficient, despite the high incidence of complete atrioventricular block. An alternative would be the application of RF at the beginning point of the septal gradient guided by the transesophageal echocardiography (TEE). The echocardiography is an imaging method with high accuracy to determine septal anatomy. OBJECTIVE: To assess the long term effect of septal ablation for the relief of ventricular-arterial gradient, using TEE to help place the catheter in the area of larger septal obstruction. Besides, to assess the effects of ablation on the functional class and echocardiographic parameters. METHODS: Twelve asymptomatic patients, with LVOT obstruction, refractory to pharmacological therapy, underwent endocardial septal ablation with 8mm-tip catheters, whose placement was oriented in the region of larger obstruction, assisted by the TEE. Temperature-controlled and staggered RF applications were performed. After each application, the gradient was reassessed and a new application was performed according to the clinical criterion. The effects of RF applications were assessed both for the gradient at rest and for that provoked by the Valsalva maneuver, and considering the gradient. The differences were significant when p-value was lower than or equal to 0.05. RESULTS: It was possible to observe that the mean reduction of the maximum gradients was from 96.8±34.7 mmHg to 62.7±25.4 mmHg three months after the procedure (p=0.0036). After one year, the mean of maximum gradient was 36.1±23.8 mmHg (p=0.0001). The procedure was well tolerated, without records of complete atrioventricular block nor severe complications. CONCLUSION: The TEE-guided septal ablation was efficient and safe, and the results were maintained during the clinical follow-up period. It is a reasonable option for the interventionist treatment of LVOT obstruction in HCM.

FUNDAMENTOS: A cardiomiopatia hipertrófica (CMH) pode causar obstrução da via de saída do ventrículo esquerdo (VSVE) e ser responsável pelo surgimento de sintomas limitantes, como cansaço físico. Quando tais sintomas são refratários ao tratamento farmacológico, os tratamentos alternativos intervencionistas podem ser úteis, como a ablação septal por meio da infusão de álcool na artéria coronária ou por meio da miectomia cirúrgica. Recentemente, o uso de cateter de radiofrequência (RF) para ablação do septo endocárdico guiado por mapeamento eletroanatômico mostrou-se eficaz apesar da elevada incidência de bloqueio atrioventricular total. Uma alternativa seria a aplicação de radiofrequência no ponto de início do gradiente septal guiada pelo ecocardiograma transesofágico (ETE). O ecocardiograma é um método de imagem com elevada acurácia para determinação da anatomia septal. OBJETIVO: Avaliar o efeito em longo prazo da ablação septal para alívio do gradiente ventrículo-arterial, utilizando o ETE para auxiliar no posicionamento do cateter na área de maior obstrução septal. Avaliar também os efeitos da ablação na classe funcional e parâmetros ecocardiográficos. MÉTODOS: Doze pacientes sintomáticos com obstrução da VSVE, refratários à terapia farmacológica, foram submetidos à ablação endocárdica septal com cateteres com ponta de 8 mm, cujo posicionamento foi orientado na região de maior obstrução com auxílio do ETE. Foram realizadas aplicações de radiofrequência (RF) termocontrolada e escalonadas sobre a área alvo. Após cada aplicação, o gradiente era reavaliado e nova aplicação era realizada de acordo com critério clínico. Foram avaliados os efeitos das aplicações de RF tanto para o gradiente em repouso como para o provocado por meio da manobra de Valsalva, e considerado o gradiente. As diferenças foram significativas quando o valor de p foi menor ou igual a 0,05. RESULTADOS: Observou-se que a redução da média dos gradientes máximos obtidos foi de 96,8±34,7 mmHg para 62,7±25,4 mmHg ao final de três meses do procedimento (p=0,0036). Após um ano, a média dos gradientes máximos obtidos foi de 36,1±23,8 mmHg (p=0,0001). O procedimento foi bem tolerado e não houve registro de bloqueio atrioventricular total e nem complicações graves. CONCLUSÃO: A ablação septal guiada pelo ETE foi eficaz e segura, com resultados mantidos durante o período de seguimento clínico. É uma opção razoável para o tratamento intervencionista da obstrução da VSVE em CMH.

Home-based training program in patients with chronic heart failure and reduced ejection fraction: a randomized pilot study.

OBJECTIVES: We aimed to compare the effects of home-and center-based exercise training programs on functional capacity, inspiratory muscle strength, daily physical activity level, and quality of life (QoL) in patients with chronic heart failure (CHF) over a 12-week period. METHODS: This study included 23 patients with CHF (left ventricular ejection fraction 31±6%) randomized to a home-based (n=11) or center-based (n=12) program. Patients underwent 12 weeks of aerobic training (60%-70% heart rate reserve): walking for the home-based and supervised cycling for the center-based group, both combined with resistance training (50% of 1 maximum repetition). At baseline and after 12 weeks of training, we assessed cardiopulmonary test variables, 6-min walk test distance (6 MWD), steps/day with accelerometry, and QoL (Minnesota Living with Heart Failure questionnaire). Maximal inspiratory pressure and handgrip strength were measured at baseline and after 4, 8, and 12 weeks of training. ClinicalTrials.gov: NCT03615157. RESULTS: There were no adverse events during training in either group. The home- and center-based training groups obtained similar improvements in peak oxygen uptake, maximal ventilation, and 6 MWD. However, there were significant between-group differences: center-based training was more effective in improving maximal inspiratory pressure (p=0.042), number of steps/day (p=0.001), and QoL (p=0.039). CONCLUSIONS: Home-based training is safe and can be an alternative to improve the exercise capacity of patients with stable CHF. However, center-based training was superior in improving inspiratory muscle strength, QoL, and daily physical activity.

Focused Endocardial Septal Ablation: A New Technique to Treat Postmyectomy Recurrent Gradient.

This report describes the case of a 64-year-old woman with a previous diagnosis of obstructive hypertrophic cardiomyopathy who underwent surgical myectomy but who had a persistent midventricular residual gradient. The patient was symptomatic despite medical treatment and chose to undergo percutaneous radiofrequency (RF) ablation focused on the gradient. RF delivery was performed, and the gradient was reduced from the initial 105/68 mm Hg (during Valsalva maneuver/at rest before ablation) to 24/10 mm Hg. This reduction was sustained for the next 12 months. Percutaneous RF ablation may be a reasonable option for second surgical myectomy, and the protocol can be easily reproduced.

Association of variants in MYH7, MYBPC3 and TNNT2 with sudden cardiac death-related risk factors in Brazilian patients with hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is characterized by unexplained left ventricular hypertrophy (LVH) and is one of the major causes of sudden cardiac death (SCD). An exon-targeted gene sequencing strategy was used to investigate the association of functional variants in sarcomeric genes (MYBPC3, MYH7 and TNNT2) with severe LVH and other SCD-related risk factors in Brazilian HCM patients. Clinical data of 55 HCM patients attending a Cardiology Hospital (Sao Paulo city, Brazil) were recorded. Severe LVH, aborted SCD, family history of SCD, syncope, non-sustained ventricular tachycardia and abnormal blood pressure in response to exercise were evaluated as SCD risk factors. Blood samples were obtained for genomic DNA extraction and the exons and untranslated regions of the MYH7, MYBPC3 and TNNT2 were sequenced using Nextera® and MiSEq® reagents. Variants were identified and annotated using in silico tools, and further classified as pathogenic or benign according to the American College of Medical Genetics and Genomics guidelines. Variants with functional effects were identified in MYBPC3 (n = 9), MYH7 (n = 6) and TNNT2 (n = 4). The benign variants MYBPC3 p.Val158Met and TNNT2 p.Lys263Arg were associated with severe LVH (p < 0.05), and the MYH7 p.Val320Met (pathogenic) was associated with family history of SCD (p = 0.037). Increased risk for severe LVH was found in carriers of MYBPC3 Met158 (c.472 A allele, OR = 13.5, 95% CI = 1.80-101.12, p = 0.011) or combined variants (MYBPC3, MYH7 and TNNT2: OR = 12.39, 95% CI = 2.14-60.39, p = 0.004). Carriers of TNNT2 p.Lys263Arg and combined variants had higher values of septum thickness than non-carriers (p < 0.05). Molecular modeling analysis showed that MYBPC3 158Met reduces the interaction of cardiac myosin-binding protein C (cMyBP-C) RASK domain (amino acids Arg215-Ala216-Ser217-Lys218) with tropomyosin. In conclusion, the variants MYBPC3 p.Val158Met, TNNT2 p.Lys263Arg and MYH7 p.Val320Met individually or combined contribute to the risk of sudden cardiac death and other outcomes of hypertrophic cardiomyopathy.

Electrophysiological study in chagasics with syncope and conduction disorder

SUMMARY BACKGROUND: Investigation of syncope involves the use of electrophysiological study, particularly in patients with cardiac conduction disorder. There is conflicting evidence about the role of electrophysiological study in patients with Chagas disease. OBJECTIVE: The objective of this study was to evaluate the electrophysiological study findings in patients with Chagas disease and bundle branch block and/or divisional block presenting with syncope. METHODS: This is a retrospective study of patients with Chagas disease and cardiac conduction disorder who underwent electrophysiological study from 2017 to 2021 for the investigation of syncope in a tertiary hospital in São Paulo, Brazil. Those with non-interpretable ECG, known coronary artery disease, and/or other cardiomyopathies were excluded. HV interval and electrophysiological study-induced malignant ventricular arrhythmias data were analyzed. RESULTS: A total of 45 patients (60.2±11.29 years, 57.8% males) were included. The mean HV interval was 58.37 ms±10.68; 22.2% of the studied population presented an HV interval of ≥70 ms; and malignant ventricular arrhythmias were induced in 57.8% patients. The use of beta-blockers and amiodarone (p=0.002 and 0.036, respectively), NYHA functional class≥II (p=0.013), wide QRS (p=0.047), increased HV interval (p=0.02), Rassi score >6.5 (p=0.003), and reduced left ventricular ejection fraction (p=0.031) were associated with increased risk of inducible malignant ventricular arrhythmias. CONCLUSION: More than half of the patients with Chagas disease, syncope, and cardiac conduction disorder have inducible malignant ventricular arrhythmias. Prolonged HV interval was observed in only 20% of population. Wide QRS, prolonged HV, reduced ejection fraction, and higher Rassi score were associated with increased risk of malignant ventricular arrhythmias.

Successful Treatment of Ventricular Arrhythmia in Tetralogy of Fallot Repair Using Catheter Ablation.

Tetralogy of Fallot (ToF) is one of the most prevalent congenital heart disease. Its surgical corrections may haemodinamically correct a disease, but the incisions may create scars that will originate ventricular arrhythmias. Even though life threatening arrhythmias are not common, some patients present unstable ventricular tachycardia (VT) of ectopic ventricular beats triggering heart failure and symptoms. We describe the treatment of a 16-years-old woman with late ToF repair and drug refractory Implantable cardioverter defibrillator (ICD) shocks. The patient underwent successful ablation of VT using X-ray and anatomic landmarks without the use of electroanatomical mapping. We were able to reduce drugs after one month of ablation and improve quality of life and symptoms. In this paper we describe the indications and perform a brief review of the key points for successful radiofrequency catheter ablation of VT in ToF patients.

Electrocardiography scar quantification correlates with scar size of hypertrophic cardiomyopathy seen by multidetector computed tomography.

BACKGROUND: Hypertrophic cardiomyopathy (HCM), a genetically transmitted disease, is the most common genetic cardiovascular disease. Current strategies to stratify risk are expensive and concentrated in wealthy centers. Twelve-lead electrocardiography (ECG) is inexpensive, universally available, and can be readily used for Selvester QRS scoring, which estimates scar size. This study aimed to establish the relation between ECG scar quantification and myocardial fibrosis (extent of myocardial delayed enhancement) in multidetector computed tomography (MDCT). HYPOTHESIS: There is a significant association between ECG scar quantification and the extent of myocardial delayed enhancement in MDCT. METHODS: Seventy-five patients with HCM underwent a routine clinical evaluation and echocardiography, 12-lead ECG, and MDCT study. Patients with and without an implantable cardioverter-defibrillator were included. RESULTS: The estimated Selvester QRS score of myocardial fibrosis was correlated significantly (R = 0.70; P < 0.01) with the quantified MDCT fibrosis. Compared with MDCT, the QRS score had 84.8% sensitivity and 88.8% specificity. Myocardial fibrosis was present in 88% of these patients with HCM (fibrotic mass, 9.87 ±10.8 g) comprising 5.66% ±6.16% of the total myocardial mass seen on the MDCT images. The Selvester QRS score reliably predicted the fibrotic mass in 76% of patients, which estimated 8.44% ±7.39% of the total myocardial mass. CONCLUSIONS: The Selvester QRS score provides reliable quantification of myocardial fibrosis and was well correlated with MDCT in patients with HCM.

Amplitude das Ondas F como Preditor de Tromboembolismo e de Sucesso da Cardioversão Elétrica em Pacientes com Fibrilação Atrial Persistente / F Wave Amplitude as a Predictor of Thromboembolism and Success of Electrical Cardioversion in Patients with Persistent Atrial Fibrillation

Resumo Fundamento A fibrilação atrial (FA) é classificada, de acordo com a amplitude das ondas fibrilatórias (f), em ondas finas (FAf) e ondas grossas (FAg). Objetivos Correlacionar a amplitude das ondas f com variáveis clínicas, laboratoriais, eletrocardiográficas e ecocardiográficas que indiquem alto risco de tromboembolismo e avaliar o seu impacto no sucesso da cardioversão elétrica (CVE). Métodos Estudo retrospectivo, observacional, que incluiu 57 pacientes com FA não valvar persistente submetidos a CVE. A amplitude máxima das ondas f foi aferida na derivação V1. FAg foi definida quando f≥1,0 mm e FAf quando f<1,0mm. Os achados foram correlacionados com as variáveis indicadas. Valores de p<0,05 foram considerados estatisticamente significativos. Resultados FAg (n=35) associou-se a maior sucesso na CVE (94,3% vs. 72,7%, p=0,036) mesmo após ajuste para variáveis como idade e IMC (p=0,026, OR=11,8). Pacientes com FAf (n=22) necessitaram mais choques e maior energia para reversão ao ritmo sinusal (p=0,019 e p=0,027, respectivamente). Não houve associação significativa entre a amplitude das ondas f e parâmetros clínicos, ecocardiográficos e laboratoriais. Conclusões A amplitude de f não se associou a parâmetros ecocardiográficos, clínicos e laboratoriais que indicam alto risco de tromboembolismo. FAg associou-se a maior chance de sucesso na reversão ao ritmo sinusal por meio da CVE. Maior número de choques e energia foram necessários para reversão ao ritmo sinusal em pacientes com FAf.

Abstract Background Atrial fibrillation (AF) is classified according to the amplitude of fibrillatory waves (f) into fine waves (fAF) and coarse waves (cAF). Objectives To correlate the amplitude of f waves with clinical, laboratory, electrocardiographic, and echocardiographic variables that indicate a high risk of thromboembolism and to assess their impact on the success of electrical cardioversion (ECV). Methods Retrospective, observational study that included 57 patients with persistent non-valvular AF who underwent ECV. The maximum amplitude of f waves was measured in lead V1. cAF was defined when f ≥ 1.0mm and fAF when f < 1.0mm. The findings were correlated with the indicated variables. Values of p < 0.05 were considered statistically significant. Results cAF (n = 35) was associated with greater success in ECV (94.3% vs. 72.7%, p = 0.036) even after adjusting for variables such as age and BMI (p = 0.026, OR = 11.8). Patients with fAF (n = 22) required more shocks and more energy to revert to sinus rhythm (p = 0.019 and p = 0.027, respectively). There was no significant association between f-wave amplitude and clinical, echocardiographic, and laboratory parameters. Conclusions The amplitude of f wave was not associated with echocardiographic, clinical and laboratory parameters that indicate a high risk of thromboembolism. cAF was associated with a higher chance of success reverting to sinus rhythm employing ECV. A greater number of shocks and energy were required for reversion to sinus rhythm in patients with fAF.