Mechanism of Shengmaisan Regulating Cardiac Remodeling of Arrhythmias with Deficiency of Qi and Yin / 中国实验方剂学杂志

Arrhythmia is an important disease among cardiovascular diseases. Malignant arrhythmias often occur clinically and are induced by abnormal ion channels， electrical activity disorders， myocardial fibrosis， inflammation， dysfunctional mitochondrial biogenesis， mitochondrial calcium overload， out-of-balance energy metabolism， oxidative stress， sympathetic hyperactivity， and other pathological cardiac remodeling， and they are the main causes of sudden cardiac death. In traditional Chinese medicine， arrhythmias are considered to be palpitations， which are commonly caused by deficiency of Qi and Yin. It is often manifested as a deficiency of the spleen and stomach， resulting in malfunction of the Qi mechanism， followed by a particularly severe decline in cardiac function. Shengmaisan is a representative formula for nourishing Qi and Yin， consisting of Ginseng Radix et Rhizoma， Ophiopogonis Radix， and Schisandrae Chinensis Fructus. In recent years， clinical studies have shown that Shengmaisan and its additions and subtractions are commonly used in the treatment of arrhythmias. In this article， the mechanisms of the active ingredients of Shengmaisan in the electrophysiology， biochemistry， structure， autonomic nervous system， and subcellular fraction of the heart are reviewed， and the multi-target， multi-system， and integrality of Shengmaisan in the treatment of arrhythmias of Qi and Yin deficiency are described. In addition， energy metabolism disorder is tightly juxtaposed with Qi and Yin deficiency syndrome. Mitochondria， as the center of myocardial energy metabolism， play a paramount role in cardiac remodeling， indicating that Shengmaisan will be a salient part of future research to ameliorate cardiac pathologic remodeling through energy metabolism of mitochondria， so as to provide a theoretical basis for the clinical treatment of these arrhythmias.

Evaluation of Symptomatic and Asymptomatic Outpatients in the Post-COVID-19 Period With Electrocardiographic Ventricular Depolarization and Repolarization Parameters

Abstract Background A recently identified viral illness called coronavirus disease 2019 (COVID-19) is spreading quickly. Numerous cardiovascular issues such as arrhythmias and electrocardiogram (ECG) alterations have been linked to COVID-19. Objective In this investigation, we compared ECG indicators of depolarization and repolarization heterogeneity between symptomatic individuals who complained of palpitations and chest discomfort following COVID-19 and those who did not. Methods In this prospective case-control study, 56 post-COVID-19 patients who did not have any symptoms of chest discomfort or palpitations were included in the control group and compared with a study group comprising 73 post-COVID-19 patients who presented at the outpatient clinic with complaints of chest pain and palpitation. Electrocardiographic (ECG) measures were used to assess depolarization and repolarization of the ventricles. These measures included the Tpeak-Tend (Tp-e) interval, QT dispersion (QTd), Tp-e/QT ratio, Tp-e/QTc ratio, frontal QRS-T (fQRS-T) angle, and fragmented QRS (FQRS). Two cardiologists recorded the patients' ECG data. A statistically significant result was defined as a p value less than 0.05. Results The results of multivariate analysis including FQRS, Tp-e interval, Tp-e/QT, and Tp-e/cQT showed that presence of FQRS (OR: 6.707, 95% CI: 1.733-25.952; p = 0.006) was an independent predictor of symptomatic post-COVID -19 patients. Conclusion In our study, FQRS was found to be significantly higher in symptomatic post-COVID-19 patients than in non-symptomatic post-COVID-19 patients, while Tp-e interval was found to be lower.

Efecto de los fármacos en la prolongación del QT y la aparición de muerte súbita en la COVID-19 / Effect of Drugs on QT Prolongation and Sudden Death in COVID-19

Introducción: Las evidencias científicas han demostrado que durante el período pandémico por la COVID-19 ha existido un incremento de la incidencia de muerte súbita cardiovascular, proporcional al incremento de los casos y a la letalidad por la enfermedad. Objetivos: Compilar información sobre los fármacos empleados en el tratamiento de la COVID-19 y sus posibles efectos en la prolongación del intervalo QT y la aparición de muerte súbita. Métodos: Se realizó una búsqueda de información a partir de las bases de datos PubMed, Medline y SciELO, en los idiomas español e inglés en el período de enero de 2020 a enero de 2023. Resultados: Los hallazgos más recientes sugieren que los factores relacionados con el tratamiento médico del paciente para sus enfermedades cardiovasculares previas, el empleo concomitante de drogas para otras comorbilidades, el ensayo de nuevas drogas que se investigan en la actualidad para el tratamiento de la enfermedad y el uso inadecuado de fármacos en complicaciones graves por la COVID-19, pueden ocasionar prolongación del intervalo QT y arritmias ventriculares tipo torsades de pointes, lo que puede conllevar a la aparición de muerte súbita. Conclusiones: Ha sido demostrado el efecto deletéreo de los fármacos en el tratamiento de la COVID-19 y sus posibles asociaciones a la terapéutica del paciente, en la prolongación del tiempo de repolarización ventricular cardíaca, cuya traducción eléctrica es un intervalo QT prolongado y su contribución a la génesis de arritmias malignas potencialmente fatales capaces de desencadenar un paro cardíaco y evolucionar a la muerte súbita(AU)

Scientific evidence has shown an increase in the incidence of sudden cardiovascular death during the COVID-19 pandemic period. This has been proportional to the increase in cases and mortality from the disease. Direct and indirect injury to the myocardium and vascular system allow to partially explain the statistics. Among the factors related to the medical treatment of the patient for previous cardiovascular diseases, it is the concomitant use of drugs for other comorbidities. The trial of new drugs for the treatment of this condition and the inappropriate use of drugs in serious complications from COVID-19 are currently being investigated. These can cause QT prolongation and torsades de pointes ventricular arrhythmias, which can lead to sudden death. Monitoring the QT interval is recommended, before and during treatment, in patients who come to the emergency room with a clinical condition suggestive of COVID-19. Additionally, modifiable factors favoring its prolongation should be evaluated. Decision-making in the application of therapeutic protocols in patients with COVID-19 with prolonged QTc at baseline, or with increased QTc after starting treatment, must go through the analysis of the risk/benefit ratio defined by a multi- and interdisciplinary team(AU)

Frequent Cardiovascular Manifestations Associated With SARS Cov-2 Infection: Experience at a Tertiary Hospital In Cali, Colombia

Abstract Background: Coronavirus disease 2019 (COVID-19) mainly affects the respiratory system, while the most common extrapulmonary complication of COVID-19 is cardiovascular involvement. Objective: To identify the frequency of electrocardiographic changes and cardiac arrhythmias in patients hospitalized with COVID-19 infection. Methods: This was a cross-sectional study, including patients aged >18 years with diagnosis of severe acute respiratory syndrome coronavirus 2 infection in a high-complexity hospital in Santiago de Cali, Colombia, from March to September 2020. A descriptive analysis with an analytical component and multiple logistic regression analysis were performed; all estimates were established with a 95% confidence level (CI) and a 5% significance level. Results: This study included 183 individuals; of whom 160 were considered for electrocardiographic analysis, 63% of which evidenced significant findings, the most frequent being sinus tachycardia (29.4%). The frequency of myocardial injury was 21.9% and was more common among non-survivors than among survivors (41.7% vs. 12.2%, p < 0.001). Myocardial injury was also significantly more common in patients who presented electrocardiographic findings than those who did not (26.5% vs. 12.1%, p = 0.032) and in those who required intensive care admission (31.8% vs 10.5%, p < 0.001). The strongest mortality-associated factor was the need for mechanical ventilation — odds ratio (OR), 9.14; 95% confidence interval, 3.4-24.5. Conclusions: Electrocardiographic findings in patients with COVID 19 are frequent, including newly diagnosed arrhythmias, justifying the use of cost-effective tools for the initial approach and follow-up of this affected population. Worse outcomes depend on factors such as invasive mechanical ventilation, comorbidities, age, and superinfection.

Elaboração de algoritmo para interpretação rápidadas principais arritmias cardíacas no eletrocardiograma / Algorithm Elaboration For Quick Interpretation Of The Main Heart Arrythmias In The Electrocardiogram

Objetivo: relatar a elaboração de um algoritmo para facilitar a interpretação rápida das principais arritmias cardíacas no eletrocardiograma. Método: estudo descritivo, exploratório, com abordagem qualitativa, do tipo relato de experiência, realizado mediante um projeto de intervenção em educação em saúde durante o ano de 2021. Resultados: a elaboração do algoritmo denominado Scaritmo contribuiu para sistematizar as etapas de identificação de arritmias cardíacas, favorecendo o processo didático e aprendizado dos estudantes e otimizando a interpretação rápida do eletrocardiograma. Conclusão: o uso do algoritmo Scaritmo permite a sistematização teórico-prática das etapas necessárias para a interpretação do eletrocardiograma tornando sua avaliação mais didática e assertiva pelo examinador em treinamento.(AU)

Objective: to report the development of an algorithm to facilitate the rapid interpretation of the main cardiac arrhythmias in electrocardiogram. Method: a descriptive, exploratory study with qualitative approach, of experience report type, conducted through an intervention project in health education during the year 2021. Results: The development of the algorithm called Scaritmo contributed to systematize the steps of cardiac arrhythmia identification, favoring the didactic process and student learning, and optimizing the rapid interpretation of the electrocardiogram. Conclusion: The use of the Scaritm algorithm allows the theoretical and practical systematization of the steps necessary for the interpretation of electrocardiograms, making its evaluation more didactic and assertive by the examiner in training.(AU)

Objetivo: relatar el desarrollo de un algoritmo para facilitar la interpretación rápida de las principales arritmias cardíacas en electrocardiograma. Método: estudio descriptivo, exploratorio, con abordaje cualitativo, de tipo relato de experiencia, realizado a través de un proyecto de intervención en educación para la salud durante el año 2021. Resultados: el desarrollo del algoritmo denominado Scaritmo contribuyó para sistematizar los pasos de identificación de arritmias cardíacas, favoreciendo el proceso didáctico y el aprendizaje de los alumnos y optimizando la rápida interpretación del electrocardiograma. Conclusión: El uso del algoritmo Scaritmo permite la sistematización teórica y práctica de los pasos necesarios para la interpretación del electrocardiograma, tornando su evaluación más didáctica y asertiva por el examinador en formación.(AU)

Cardioverter-defibrillator reduces mortality risk in eligible ischemic and non-ischemic cardiomyopathy patients: Sub-analysis of the multi-center Improve SCA study

Background & Objective: Despite the burden of sudden cardiac arrest (SCA) worldwide, implantable cardioverter-defibrillators (ICDs) are underutilized, particularly in Asia, Latin America, Eastern Europe, the Middle East, and Africa. The Improve SCA trial demonstrated that primary prevention (PP) patients in these regions benefit from an ICD or a cardiac resynchronization therapy defibrillator (CRT-D). We aimed to compare the rate of device therapy and mortality among ischemic and non-ischemic cardiomyopathy (ICM and NICM) PP patients who met guideline indications for ICD therapy and had an ICD/CRT-D implanted. Methods: Improve SCA was a prospective, non-randomized, non-blinded multicenter trial that enrolled patients from the above-mentioned regions. All-cause mortality and device therapy were examined by cardiomyopathy (ICM vs NICM) and implantation status. Cox proportional hazards methods were used, adjusting for factors affecting mortality risk. Results: Of 1848 PP NICM patients, 1007 (54.5%) received ICD/CRT-D, while 303 of 581 (52.1%) PP ICM patients received an ICD/CRT-D. The all-cause mortality rate at 3 years for NICM patients with and without an ICD/CRT-D was 13.1% and 18.3%, respectively (HR 0.51, 95% CI 0.38e0.68, p < 0.001). Similarly, all-cause mortality at 3 years in ICM patients was 13.8% in those with a device and 19.9% in those without an ICD/CRT-D (HR 0.54, 95% CI 0.33e.0.88, p ¼ 0.011). The time to first device therapy, time to first shock, and time to first antitachycardia pacing (ATP) therapy were not significantly different between groups (p 0.263). Conclusions: In this large data set of patients with a guideline-based PP ICD indication, defibrillator device implantation conferred a significant mortality benefit in both NICM and ICM patients. The rate of appropriate device therapy was also similar in both groups.

Commotio cordis (conmoción cardíaca) en un niño. Reporte de un caso / Commotio cordis (cardiac concussion) in a child. A case report

Commotio cordis o conmoción cardíaca es un síndrome arritmogénico mecano-eléctrico raro y mortal. Es la segunda causa de muerte súbita en atletas jóvenes. Se asocia con una lesión que se produce durante la práctica deportiva, en la que un proyectil impacta a alta velocidad en el precordio y provoca una arritmia que conduce a la muerte inmediata del individuo sin una reanimación cardíaca. En las autopsias, los corazones son estructuralmente sanos. Con el conocimiento de este síndrome y las capacitaciones de reanimación cardiorrespiratoria a la comunidad, las tasas de supervivencia han mejorado. El objetivo de este trabajo es describir un paciente que llegó a nuestro hospital con conmotio cordis y su evolución, enfatizando la importancia de medidas de prevención y capacitación de la población en técnicas de reanimación cardiopulmonar y uso del desfibrilador externo automático para la supervivencia de los pacientes que sufren esta entidad.

Commotio cordis or cardiac concussion is a rare and fatal mechano-electric arrhythmogenic syndrome. It is the second most common cause of sudden cardiac death in young athletes. It is most commonly associated with a sports-related injury, wherein, there is a high-velocity impact between a projectile and the precordium, causing arrhythmia that leads to the immediate death of the individual without cardiac resuscitation. On autopsy, the heart is structurally normal. With increasing awareness of this condition and community training in cardiopulmonary resuscitation, survival rates have been improving. The objective of this study is to describe the case of a patient who arrived at our hospital with commotio cordis and his course, emphasizing the importance of prevention and training of the population in cardiopulmonary resuscitation techniques and the use of the automated external defibrillator for the survival of patients suffering from commotio cordis.

Fibrilación auricular una arritmia y un sindrome / Atrial fibrillation, an arrhythmia and a syndrome

Atrial Fibrillation (AF) is the most common sustained arrhythmia and is highly prevalent in elderly patients. It confers a higher risk for ischemic stroke, heart failure and death. The diagnosis and treatment of AF has been extensively studied and remain under constant revision. This article reviews the recent European guidelines and the advances observed with the introduction of direct oral anticoagulants in the last ten years. This new family of drugs has clear benefits in terms of efficacy and safety compared with traditional vitamin K antagonists. Treatment of most common comorbidities in patients with AF such as advanced age, heart failure, diabetes, renal failure, and others are also analyzed. New therapies for AF will be shortly available.

Electrocardiogram classification algorithm based on CvT-13 and multimodal image fusion / 生物医学工程学杂志

Electrocardiogram (ECG) signal is an important basis for the diagnosis of arrhythmia and myocardial infarction. In order to further improve the classification effect of arrhythmia and myocardial infarction, an ECG classification algorithm based on Convolutional vision Transformer (CvT) and multimodal image fusion was proposed. Through Gramian summation angular field (GASF), Gramian difference angular field (GADF) and recurrence plot (RP), the one-dimensional ECG signal was converted into three different modes of two-dimensional images, and fused into a multimodal fusion image containing more features. The CvT-13 model could take into account local and global information when processing the fused image, thus effectively improving the classification performance. On the MIT-BIH arrhythmia dataset and the PTB myocardial infarction dataset, the algorithm achieved a combined accuracy of 99.9% for the classification of five arrhythmias and 99.8% for the classification of myocardial infarction. The experiments show that the high-precision computer-assisted intelligent classification method is superior and can effectively improve the diagnostic efficiency of arrhythmia as well as myocardial infarction and other cardiac diseases.

An image classification method for arrhythmias based on Gramian angular summation field and improved Inception-ResNet-v2 / 生物医学工程学杂志

Arrhythmia is a significant cardiovascular disease that poses a threat to human health, and its primary diagnosis relies on electrocardiogram (ECG). Implementing computer technology to achieve automatic classification of arrhythmia can effectively avoid human error, improve diagnostic efficiency, and reduce costs. However, most automatic arrhythmia classification algorithms focus on one-dimensional temporal signals, which lack robustness. Therefore, this study proposed an arrhythmia image classification method based on Gramian angular summation field (GASF) and an improved Inception-ResNet-v2 network. Firstly, the data was preprocessed using variational mode decomposition, and data augmentation was performed using a deep convolutional generative adversarial network. Then, GASF was used to transform one-dimensional ECG signals into two-dimensional images, and an improved Inception-ResNet-v2 network was utilized to implement the five arrhythmia classifications recommended by the AAMI (N, V, S, F, and Q). The experimental results on the MIT-BIH Arrhythmia Database showed that the proposed method achieved an overall classification accuracy of 99.52% and 95.48% under the intra-patient and inter-patient paradigms, respectively. The arrhythmia classification performance of the improved Inception-ResNet-v2 network in this study outperforms other methods, providing a new approach for deep learning-based automatic arrhythmia classification.

Advancements in pharmacological therapy for transthyretin cardiac amyloidosis and its comorbidities / 中国药房

Transthyretin cardiac amyloidosis myocardiopathy （ATTR-CM） is an infiltrative cardiomyopathy characterized by the deposition of amyloidogenic material in the myocardial interstitium due to the misfolding of monomers following the dissociation of unstable transthyretin （TTR） tetramers. Previous treatments for ATTR-CM lacked specificity，primarily targeting symptomatic management of heart failure and arrhythmias. In recent years，researchers have developed two major classes of drugs addressing the pathogenesis of ATTR-CM. The first class stabilizes TTR tetramer structure （such as tafamidis and acoramidis）， while the second class interferes with TTR synthesis （such as patisiran）. Among these，tafamidis has been confirmed as the only currently effective treatment for ATTR-CM，while other drugs are still in clinical trial stages with limited clinical evidence. Concerning the management of comorbidities in ATTR-CM，treatment mainly focuses on common cardiac comorbidities （such as heart failure and arrhythmias）. Traditional drugs used to improve heart failure prognosis （such as β-blockers and renin-angiotensin- receptor blocker），have not demonstrated prognosis improvement in ATTR-CM patients and may even lead to adverse reactions. For ATTR-CM patients with concurrent atrial fibrillation，anticoagulation therapy is recommended to prevent thrombus formation，and amiodarone can be used for rhythm control. Despite significant advancements in pharmaceutical treatments for ATTR-CM，the overall prognosis remains poor，necessitating further research into the pathogenesis and target development to enhance the prognosis of ATTR-CM patients.

Clinical analysis of 24-hour dynamic electrocardiographic changes in 323 middle-aged and older adult patients with cardiovascular disease / 中国基层医药

Objective:To analyze the 24-hour dynamic electrocardiographic changes in middle-aged and older adult patients with cardiovascular disease, providing effective guidance for clinical targeted intervention.Methods:The clinical data of 232 middle-aged and older adult patients who received treatment in Shanxi Coal Central Hospital from April 2019 to April 2021 were retrospectively analyzed. Among these patients, 166 patients with cardiovascular disease aged ≥ 60 years were included in the observation group, and 157 patients with cardiovascular disease aged < 60 years were included in the control group. The 24-hour dynamic electrocardiographic changes were compared between the two groups.Results:The detection rates of atrial arrhythmias, ventricular arrhythmias, sinus arrhythmias, complex ventricular arrhythmias, and complex atrial arrhythmias in the observation group were 96.99%, 88.55%, 28.31%, 39.76%, and 52.41% respectively, which were significantly higher than 50.32%, 50.96%, 8.28%, 9.55%, 8.92% in the control group ( χ2 = 19.21, 28.75, 23.45, 6.90, 8.06, all P < 0.001). The time of myocardial ischemia attack in the observation group [(1.5 ± 0.5) minutes] was significantly shorter than that in the control group [(2.5 ± 0.5) minutes, t = 23.09, P < 0.001)]. The time of myocardial ischemia attack in the observation group was mostly from 0:00 a.m. to 8:00 a.m. Conclusion:Patients aged ≥ 60 years are more likely to develop cardiovascular disease. The risk of cardiovascular diseases increase with increasing age. In particular at 0:00 a.m. to 8:00 a.m., 24-hour dynamic electrocardiographic changes should be monitored to further understand the actual situation of patients and guide clinical effective prevention and treatment of myocardial ischemia.

Predictive value of dynamic electrocardiography for myocardial ischemia and arrhythmia in patients with coronary heart disease / 中国基层医药

Objective:To investigate the predictive value of dynamic electrocardiography (ECG) for myocardial ischemia and arrhythmia in patients with coronary heart disease.Methods:A total of 87 patients with coronary heart disease who received treatment in Wenling Hospital of Traditional Chinese Medicine from January 2020 to January 2022 were included in this study. These patients were divided into a conventional ECG group (group A, n = 40) and a dynamic ECG group (group B, n = 47) according to different examination methods. The detection rate of myocardial ischemia in the two groups was determined. The diagnostic efficacy of routine ECG and dynamic ECG for myocardial ischemia was analyzed according to the results of coronary angiography. The detection rate of arrhythmia was determined in each group. Patient satisfaction was compared between the two groups. Results:There was no significant difference in the total detection rate of myocardial ischemia between the two groups ( P = 0.154). The detection rate of asymptomatic myocardial ischemia in group B [25% (25/47)] was significantly higher than that in group A [10% (10/40), χ2 = 5.24, P = 0.020). According to the results of coronary angiography, the detection rates of myocardial ischemia in group A and group B were 68% (27/40) and 87% (41/47), respectively. The sensitivity, specificity, and accuracy of group B in diagnosing myocardial ischemia were 80% (33/41), [67% (4/6), and 74% (35/47), respectively, all of which were significantly higher than 74% (20/27), [46% (6/13), 68% (27/40) in group A ( χ2 = 8.03, 5.89, 5.03, P = 0.003, 0.012, 0.005). The detection rates of premature ventricular contraction in bi-triplet rhythm, frequent paired premature atrial contraction in bi-triplet rhythm, right bundle-branch block, atrioventricular block, supraventricular tachycardia in group B were significantly higher compared with group A ( χ2 = 10.78, P = 0.001). According to the results of coronary angiography, the detection rates of arrhythmia in groups A and B were 65% (26/40) and 79% (37/47), respectively. The sensitivity, specificity, and accuracy of diagnosing arrhythmia in coronary heart disease in group B were 86% (32/37), 40% (4/10), and 81% (38/47), respectively. The sensitivity and accuracy of diagnosing arrhythmia in coronary heart disease in group B were significantly higher than those in group A [58% (15/26), 55% (22/40), χ2 = 7.30, 4.90, P = 0.005, 0.010). Patient satisfaction in group B [87% (41/47)] was significantly higher than that in group A [65% (26/40), χ2 = 6.24, P = 0.044]. Conclusion:Compared with conventional ECG detection, dynamic ECG has substantially higher detection and diagnosis rates of myocardial ischemia and arrhythmia, as well as a higher patient satisfaction rate, in patients with coronary heart disease, in particular in those with asymptomatic myocardial ischemia.

Evaluation and management of heart failure with arrhythmias in children / 中国小儿急救医学

Heart failure is the end-stage clinical manifestation of various functional or structural heart diseases, which is an acute and critical condition in the field of pediatrics.Arrhythmias are often complicated with heart failure in children and could also trigger heart failure exacerbation, affecting the prognosis of children.The clinical manifestations of arrhythmias in children are atypical except the malignant types, and children with heart failure should always be alerted to the possibility of arrhythmias.Therefore, it is important for improving the prognosis of children with heart failure by raising awareness of these diseases, thus making a rational assessment of disease and actively managing it.

Study on the effect of spinal anesthesia on ventricular arrhythmias in acute myocardial ischemia-reperfusion in rats / 中国临床药理学与治疗学

AIM: To explore the effect of spinal anesthesia on ventricular arrhythmia and involved mechanisms in myocardial ischemia-reperfusion (MIR) rats. METHODS: The rat MIR model was made by occlusion the left anterior descending coronary artery for 30 minutes and reperfusion for 45 minutes. Bupivacaine (0.05 mL / 100 g, 1 mg / kg) was injected slowly via intrathecal for spinal anesthesia. The electromyelogram at T2 thoracic spinal cord was recorded. Ventricular arrhythmias, cardiac function, myocardial damage were assessed by electrocardiography, echocardiography and TTC or HE staining. RESULTS: MIR reduced left ventricular short-axis shortening (LVFS) and left ventricular ejection fraction (LVEF), caused myocardial histological damage and ventricular arrhythmias, promoted spinal electrical discharge frequency and amplitude in T2 dorsal horn. Spinal injection of bupivacaine could significantly reduce spinal cord electrical activities and eliminate MIR-induced arrhythmias. Moreover, bupivacaine also significantly improved MIR-induced myocardial histological damage and cardiac function inhibition. CONCLUSION: Spinal anesthesia can reduce ventricular arrhythmias induced by MIR. The mechanism may be related to the effect of abolishing spinal nerve excitability.

Estudo Morfofuncional do Átrio Esquerdo Isolado de um Modelo Experimental de Hipertensão Pulmonar em Ratos / Isolated Left Atrium Morphofunctional Study of an Experimental Pulmonary Hypertension Model in Rats

Resumo Fundamento A alta incidência de arritmias atriais na hipertensão pulmonar (HP) pode estar associada a um prognóstico ruim, e o átrio esquerdo (AE) pode desempenhar um papel neste quadro. Um achado importante nos estudos de HP é que a remodelação do AE é subestimada. Objetivo Este estudo investigou a morfologia e a função mecânica do AE, bem como a suscetibilidade ao desenvolvimento de arritmias em um modelo de HP induzida por monocrotalina (HP-MCT). Métodos Ratos Wistar com 4 semanas de idade receberam 50 mg/kg de MCT. Foram realizadas análises eletrocardiográficas e histológicas para avaliar o estabelecimento do modelo de HP-MCT. O tecido foi montado em banho de órgão isolado para caracterizar a função mecânica do AE. Resultados Em comparação com o grupo controle, o modelo de HP-MCT apresentou hipertrofia do AE e alterações da atividade elétrica cardíaca, conforme evidenciadas pelo aumento da duração da onda P, PR e intervalo QT. Não foi observada alteração no inotropismo do AE isolado de ratos com HP-MCT; no entanto, o tempo para atingir a contração máxima foi atrasado. Finalmente, não observamos diferença na suscetibilidade à arritmia no AE dos ratos com HP-MCT após o protocolo de estimulação intermitente. Conclusão A remodelação morfofuncional do AE não levou ao aumento da suscetibilidade à arritmia ex vivo após a aplicação do protocolo de estimulação intermitente.

Abstract Background The high incidence of atrial arrhythmias in pulmonary hypertension (PH) might be associated with poor prognosis, and the left atrium (LA) may play a role in this. An important finding in PH studies is that LA remodeling is underestimated. Objective This study investigated LA morphology and mechanical function, as well as the susceptibility to develop arrhythmias in a monocrotaline-induced PH (MCT-PH) model. Methods Wistar rats aged 4 weeks received 50 mg/kg of MCT. Electrocardiography and histology analysis were performed to evaluate the establishment of the MCT-PH model. The tissue was mounted in an isolated organ bath to characterize the LA mechanical function Results Compared with the control group (CTRL), the MCT-PH model presented LA hypertrophy and changes in cardiac electrical activity, as evidenced by increased P wave duration, PR and QT interval in MCT-PH rats. In LA isolated from MCT-PH rats, no alteration in inotropism was observed; however, the time to peak contraction was delayed in the experimental MCT-PH group. Finally, there was no difference in arrhythmia susceptibility of LA from MCT-PH animals after the burst pacing protocol. Conclusion The morphofunctional remodeling of the LA did not lead to increased susceptibility to ex vivo arrhythmia after application of the burst pacing protocol.

KCNH2 mutation c.3099_3112del causes congenital long QT syndrome type 2 with gender differences

Abstract Introduction: Long QT Syndrome (LQTS) is an inherited disease with an abnormal electrical conduction system in the heart that can cause sudden death as a result of QT prolongation. LQT2 is the second most common subtype of LQTS caused by loss of function mutations in the potassium voltage-gated channel subfamily H member 2 (KCNH2) gene. Although more than 900 mutations are associated with the LQTS, many of these mutations are not validated or characterized. Methods and results: Sequencing analyses of genomic DNA of a family with LQT2 identified a putative mutation. i.e., KCNH2(NM_000238.3): c.3099_3112del, in KCNH2 gene which appeared to be a definite pathogenic mutation. The family pedigree information showed a gender difference in clinical features and T-wave morphology between male and female patients. The female with mutation exhibited recurring ventricular arrhythmia and syncope, while two male carriers did not show any symptoms. In addition, T-wave in females was much flatter than in males. The female proband showed a positive reaction to the lidocaine test. Lidocaine injection almost completely blocked ventricular arrhythmia and shortened the QT interval by ≥30 ms. Treatment with propranolol, mexiletine, and implantation of cardioverter-defibrillators prevented the sustained ventricular tachycardia, ventricular fibrillation, and syncope, as assessed by a 3-year follow-up evaluation. Conclusions: A putative mutation c.3099_3112del in the KCNH2 gene causes LQT2 syndrome, and the pathogenic mutation mainly causes symptoms in female progeny.

Arritmias en personas transgénero / Arrhythmias in transgender individuals

Resumen La necesidad de mejorar el acceso a servicios de salud para la comunidad transgénero se ha vuelto evidente, especialmente en relación con el riesgo cardiovascular, que es más alto en comparación con la población general. Los procedimientos quirúrgicos y las terapias hormonales son comunes en esta población para reafirmar la identidad de género, pero plantean desafíos, ya que se asocian con alteraciones en el metabolismo de lípidos, la concentración de grasa corporal y la resistencia a la insulina. Además, existe un aumento en el riesgo de eventos cardiovasculares adversos, como tromboembolia venosa, accidente cerebrovascular e infarto de miocardio. La influencia de las hormonas sexuales en las propiedades electrofisiológicas del corazón ha sido estudiada, destacando diferencias entre géneros que pueden predisponer a la población transgénero a arritmias cardiacas. La terapia hormonal exógena, tanto para mujeres como para hombres trans, puede afectar el intervalo QT y aumentar el riesgo de arritmias, incluida la fibrilación auricular. Aunque la incidencia de arritmias en la población transgénero aún no está completamente clara, la evidencia sugiere la necesidad de un monitoreo cardiovascular cuidadoso y la consideración de factores de riesgo antes de iniciar terapias hormonales.

Abstract The need to improve access to health services for the transgender community has become evident, especially concerning cardiovascular risk, which is higher compared to the general population. Surgical procedures and hormone therapies are common in this population to affirm gender identity, but they pose challenges as they are associated with disruptions in lipid metabolism, body fat concentration, and insulin resistance. Additionally, there is an increased risk of adverse cardiovascular events such as venous thromboembolism, stroke, and myocardial infarction. The influence of sex hormones on the electrophysiological properties of the heart has been studied, highlighting gender differences that may predispose the transgender population to cardiac arrhythmias. Exogenous hormone therapy, for both transgender women and men, can affect the QT interval and increase the risk of arrhythmias, including atrial fibrillation. Although the incidence of arrhythmias in the transgender population is not entirely clear, evidence suggests the need for careful cardiovascular monitoring and consideration of risk factors before initiating hormone therapies.