Research progress of visualization methods and localization techniques of the cardiac conduction system / 中国胸心血管外科临床杂志

@#The cardiac conduction system (CCS) is a set of specialized myocardial pathways that spontaneously generate and conduct impulses transmitting throughout the heart, and causing the coordinated contractions of all parts of the heart. A comprehensive understanding of the anatomical characteristics of the CCS in the heart is the basis of studying cardiac electrophysiology and treating conduction-related diseases. It is also the key of avoiding damage to the CCS during open heart surgery. How to identify and locate the CCS has always been a hot topic in researches. Here, we review the histological imaging methods of the CCS and the specific molecular markers, as well as the exploration for localization and visualization of the CCS. We especially put emphasis on the clinical application prospects and the future development directions of non-destructive imaging technology and real-time localization methods of the CCS that have emerged in recent years.

Melatonin inhibits arrhythmias induced by increased late sodium currents in ventricular myocytes / 药学学报

Melatonin (Mel) has been shown to have cardioprotective effects, but its action on ion channels is unclear. In this experiment, we investigated the inhibitory effect of Mel on late sodium currents (INa.L) in mouse ventricular myocytes and the anti-arrhythmic effect at the organ level as well as its mechanism. The whole-cell patch clamp technique was applied to record the ionic currents and action potential (AP) in mouse ventricular myocytes while the electrocardiogram (ECG) and monophasic action potential (MAP) were recorded simultaneously in mouse hearts using a multichannel acquisition and analysis system. The results demonstrated that the half maximal inhibitory concentration (IC50) values of Mel on transient sodium current (INa.T) and specific INa.L opener 2 nmol·L-1 sea anemone toxins II (ATX II) increased INa.L were 686.615 and 7.37 μmol·L-1, respectively. Mel did not affect L-type calcium current (ICa.L), transient outward current (Ito), and AP. In addition, 16 μmol·L-1 Mel shortened ATX II-prolonged action potential duration (APD), suppressed ATX II-induced early afterdepolarizations (EADs), and significantly reduced the incidence of ventricular tachycardia (VT) and ventricular fibrillation (VF) in Langendorff-perfused mouse hearts. In conclusion, Mel exerted its antiarrhythmic effects principally by blocking INa.L, thus providing a significant theoretical basis for new clinical applications of Mel. Animal welfare and experimental process are in accordance with the regulations of the Experimental Animal Ethics Committee of Wuhan University of Science and Technology (2023130).

Impact of catheter ablation procedure on optical coherence tomography angiography findings in patients with ventricular arrhythmia

SUMMARY OBJECTIVE: Catheter ablation procedure may cause retinal complications associated with the risk of thromboembolism. We aimed to evaluate retina and optic disc microvascularity with optical coherence tomography angiography before and after the catheter ablation process in patients with ventricular arrhythmia. METHODS: A total of 40 eyes of 21 ventricular arrhythmia patients were included in this cross-sectional study. Demographic characteristics and ophthalmic examination findings of patients were recorded. optical coherence tomography angiography measurements were evaluated before (group 1) and after (group 2) catheter ablation. Optical coherence tomography angiography was applied to all eyes with 6×6 mm sections for the macula and 4.5×4.5 mm sections for the optic nerve head. Foveal retinal thickness, peripapillary retinal nerve fiber layer thickness, vessel density in different parts of the retina, and optic disc were analyzed. RESULTS: The mean age of ventricular arrhythmia patients was 53.48±13.02 years. In all, 13 (61.9%) of the patients were males and 8 (38.1%) were females. There was no significant difference between the groups in terms of average, inferior, superior, and temporal retinal nerve fiber layer thicknesses, foveal avascular area, flow areas, superficial and deep vessel densities, and optic disc capillary densities of the optic disc. However, when compared with group 1, significantly lower values in foveal retinal thickness and higher values in nasal retinal nerve fiber layer thickness were observed in group 2 (248.42±20.50 vs. 247.20±20.44, p<0.001 and 94.22±18.43 vs. 96.12±20.18, p=0.044, respectively). CONCLUSION: Although foveal retinal thickness and nasal retinal nerve fiber layer thickness are affected in patients undergoing catheter ablation for ventricular arrhythmia, the stable retinal and optic disc vessel densities can be explained by the administration of effective anticoagulants during the procedure.

Uncontrolled Diabetes with Underlying Structural Changes in the Atrioventricular Node / Diabetes no Controlada con Cambios Estructurales Subyacentes en el Nodo Atrioventricular

SUMMARY: Diabetic cardiomyopathy, characterized by diabetes mellitus (DM) -induced cardiac muscular abnormalities, is a strong inducer of impaired cardiac contraction and arrhythmia. Atrioventricular block, a serious type of arrhythmia resulting from interruption of cardiac impulse conduction via the atrioventricular node (AVN), frequently occurs among diabetic patients. However, details of structural changes in AVN in DM remain poorly explained. Here, this study defined the effects of DM on the morphological remodeling of the AVN in male Sprague Dawley rats induced by intraperitoneal injection of streptozotocin (60 mg/kg body weight). At 24 weeks, the pathological changes in the AVN were assessed by light microscopy (LM) and transmission electron microscopy (TEM). Under LM, the AVN in diabetic rats became a less compact mass and exhibited the intracellular vacuolation. The nodal cells were more varied in sizes with the absence or shrinkage of nuclei and clear cytoplasm compared to the control. The collagen content significantly increased in relation to the presence of myofibroblasts. Consistent with LM, TEM images of the diabetic nodal cells revealed several signs of cell damage, such as mitochondrial changes, deterioration of cell organelles, gap junction internalization, and cell separation. Furthermore, changes in AVN innervation, evidenced by damaged Schwann cells and axons, were also found. These results indicated alterations in important components in the AVN during diabetic condition, which may lead to the impairment of electrical conduction, causing abnormal cardiac functions in diabetic patients.

La miocardiopatía diabética, caracterizada por anomalías musculares cardíacas inducidas por diabetes mellitus (DM), es un fuerte inductor de alteración de la contracción cardíaca y arritmia. El bloqueo atrioventricular, un tipo grave de arritmia resultante de la interrupción de la conducción del impulso cardíaco a través del nodo atrioventricular (NAV), se produce con frecuencia entre los pacientes diabéticos. Sin embargo, los detalles de los cambios estructurales en NAV en DM siguen estando pobremente explicados. Aquí, este estudio definió los efectos de la DM en la remodelación morfológica del NAV en ratas macho Sprague Dawley inducidas por inyección intraperitoneal de estreptozotocina (60 mg/kg de peso corporal). A las 24 semanas, los cambios patológicos en el NAV se evaluaron mediante microscopía óptica (MO) y microscopía electrónica de transmisión (MET). Bajo MO, el NAV en ratas diabéticas se convirtió en una masa menos compacta y exhibió la vacuolización intracelular. Las células nodales tenían tamaños más variados con ausencia o contracción de núcleos y citoplasma claro en comparación con el control. El contenido de colágeno aumentó significativamente en relación con la presencia de miofibroblastos. De acuerdo con MO, las imágenes MET de las células nodales diabéticas revelaron varios signos de daño celular, como cambios mitocondriales, deterioro de los orgánulos celulares, internalización de uniones comunicantes y separación celular. Además, también se encontraron cambios en la inervación del NAV, evidenciados por schwannocitos y axones dañados. Estos resultados indicaron alteraciones en componentes importantes en el NAV durante la condición diabética, lo que puede conducir al deterioro de la conducción eléctrica, causando funciones cardíacas anormales en estos pacientes.

Miocardiopatía hipertrófica en la edad pediátrica. Revisión a propósito de una serie de casos

Introducción: La miocardiopatía hipertrófica (MCH) constituye una enfermedad compleja y variable en cuanto a morfología, fisiopatología, pronóstico y sobrevida. Se caracteriza por una hipertrofia del ventrículo izquierdo, aunque en ocasiones puede ser biventricular o ventricular derecha aislada. En la edad pediátrica predominan las causas no sarcoméricas. La ecocardiografía es el método diagnóstico más utilizado para caracterizar la morfología y repercusión hemodinámica, sin embargo, la resonancia magnética cardíaca (RMC) es de elección por aportar mayores ventajas morfológicas y funcionales. Las pruebas genéticas son de gran importancia en la determinación del diagnóstico etiológico, manejo terapéutico y pronóstico. El tratamiento tiene como objetivo principal mejorar la capacidad funcional y aliviar los síntomas. Los betabloqueantes no vasodilatadores son considerados de primera líneay en algunos casos se puede recurrir a terapias avanzadas como disopiramida o terapia de reducción septal (TRS), uso del cardiodesfibrilador implantable (CDI), y en ocasiones se debe considerar trasplante cardiaco en pacientes con síntomas refractarios al tratamiento médico y en MCH del tipo obstructivo. Materiales y métodos: Estudio observacional, descriptivo, corte transversal. Resultados: Se estudiaron 12 pacientes, desde enero de 2020 a diciembre de 2022, con edades comprendidas desde 5 meses hasta 16 años, diagnosticados con MCH de presentación clínica variable y de distintas etiologías. Conclusión: La MCH de causas no sarcoméricas como los síndromes malformativos y errores innatos del metabolismo son las que tienen peor pronóstico y sobrevida. La finalidad de detectar precozmente la MCH es el inicio temprano de la terapia específica, para así retrasar el compromiso cardiovascular y mejorar la sobrevida.

Introduction: Hypertrophic cardiomyopathy (HCM) is a complex and variable disease in terms of morphology, pathophysiology, prognosis and survival. It is characterized by left ventricular hypertrophy, although it can sometimes be biventricular or isolated right ventricular. In the pediatric population, non-sarcomeric causes predominate. Echocardiography is the most widely used diagnostic method to characterize morphology and hemodynamic repercussions; however, cardiac magnetic resonance imaging (CMR) is preferred because it provides greater morphological and functional advantages. Genetic tests are of great importance in determining the etiological diagnosis, therapeutic management and prognosis. The main objective of the treatment is to improve functional capacity and alleviate symptoms. Non-vasodilator beta-blockers are considered first-line treatment and in some cases advanced therapies such as disopyramide or septal reduction therapy (SRT), use of implantable cardioverter-defibrillator (ICD) can be used; heart transplantation should be considered in patients with symptoms refractory to medical treatment and in HCM of the obstructive type. Materials and methods: This was an observational, descriptive, cross-sectional study. Results: 12 patients were studied, from January 2020 to December 2022, with ages ranging from 5 months to 16 years, diagnosed with HCM of variable clinical presentation and of different etiologies. Conclusion: HCM from non-sarcomeric causes such as malformation syndromes and inborn errors of metabolism have the worst prognosis and survival. The purpose of early detection of HCM is the early initiation of specific therapy, in order to delay cardiovascular compromise and improve survival.

Arrhythmia in Adult Congenital Heart Disease

This case report highlights the significance of a multidisciplinary approach in the management of patients with repaired membranous ventricular septal defect (VSD) who develop postoperative arrhythmias. We present the case of a young female who experienced symptomatic episodes of supraventricular tachycardia following VSD repair. Through electrophysiological study and radiofrequency ablation, multiple tachycardia substrates were identified and successfully ablated. This report underscores the importance of combining surgical repair, electrophysiological evaluation and intervention to achieve optimal outcomes in this specific patient population.

Delta of Egypt Atrial Fibrillation Registry Phase Two

Background: Atrial Fibrillation (AF) is the most frequent cardiac arrhythmia found in clinical practice. The assessed frequency of AF in adults is between 2% and 4%, with greater incidence and frequency rates in developed nations [1,2]. AF prevalence increases with advancing age, and with some cardiac and non-cardiac disorders, also it may exist in the absence of any conditions [2]. We aimed to determine case characteristics, practice patterns, management strategies and outcomes of atrial fibrillation in the delta area of Egypt. Methods: This registry-based cross-sectional study included 1000 atrial fibrillation patients (with any AF patterns) who were allowed to enter ER in cardiac centers and hospitals in middle Delta of Egypt from April 2020 to March 2021. Results: 267 patients (26.7%) were unstable. Heart failure, hypertension, and coronary disease were still prevalent comorbidities in our AF dataset, where hypertension accounts for over 50% of all AF cases. Rheumatic valvular heart disorder was a major underlying disease for the development of AF, still about 25.5% by echocardiography. Lone AF still high 20.6%. CHA2DS2VASc score ?2 is 83.5%. A high proportion of cases were treated with pharmaceuticals for rate control nearly 52.7% of the cases and nearly 30.3% of the cases were given pharmacological medications for the cardioversion to the sinus rhythm and a small proportion of the cases were given electrical cardioversion nearly 7%. Conclusions: Coronary disease, hypertension, and heart failure were still usual comorbidities in AF. Rheumatic valvular heart disease is still about 25.5% of the total registry. Amiodarone is the most prevalent antiarrhythmic medications (AAD) used. lone AF still high 20.6%. minimal use of novel oral anticoagulant (OAC).

Complete atrioventricular block secondary to the BBIBP-CorV vaccine The report of a rare adverse event; the first description in Colombia

Introduction: cardiovascular complications due to COVID-19 infection are very frequent. However, these complications are rarely reported as a vaccine reaction. Case presentation: a female patient with no significant cardiovascular history developed functional class deterioration 14 days after her third dose of the BBIBP-CorV vaccine, along with three syncopal episodes. She was seen at a primary care level and an electrocardiogram was ordered which showed Mobitz 2 atrioventricular block which progressed to a complete block. Molecular tests for COVID-19 infection were negative, as were immunological studies for collagen disease, Chagas, and viral myocarditis. A transthoracic echocardiogram showed no regional kinetic disturbances, and the ejection fraction was preserved at 60%. Cardiac magnetic resonance imaging showed edema in the T2-STIR sequences, and subepicardial enhancement in the medial distal lateral region was compatible with acute myocarditis. The patient required a permanent pacemaker. Discussion: electrical or mechanical dysfunction secondary to a COVID-19 vaccine is anecdotal, with few reports in the literature. In a review of both the 2021 European Society of Cardiology and the 2018 American Heart Association Guidelines on cardiac pacing and cardiac resynchronization therapy, no recommendation was found for these types of events associated with COVID-19 or following vaccination. An international network should be created to report these events and thus determine general management guidelines. For now, the recommendations must be individualized for these patients. (Acta Med Colomb 2022; 48. DOI:https://doi.org/10.36104/amc.2023.2602).

Programmed ventricular stimulation in structural heart disease: Implications of patterns of ventricular arrhythmias induced to long-term outcomes

Introduction: Currently available data gives some credence to utility of VT induction studies in patients with stable ischemic cardiomyopathy, there are some unresolved questions as to define sensitive threshold for low-risk and the prognostic relevance of ill sustained or non-specific tachycardia on induction study. We evaluated potential ability of VT inducibility to predict likelihood of SHD (Structural heart disease) patients for subsequent arrhythmic or adverse cardiac events. Material and Methods: All consecutive patients with syncope/documented arrhythmia who had VT induction done were included and patients with VT storm, ACS,uncontrolled HF were excluded. We studied in 4 groups-monomorphic VT, sustained polymorphicVT, ill sustainedVT/VF and no VT/VF induced. The primary-endpoints were e Sudden death, all-cause mortality and secondary-endpoints were e MACE (AICD shock, death,HF, recurrence of VT). We screened 411 patients and included 169 within inducible (n ¼ 79) and non-inducible group (n ¼ 90). Results: There were a higher number of patients with coronary artery disease, LV dysfunction, patients on amiodarone in inducible group and no difference in usage of beta-blockers. Recurrence of VT, composite of MACE was significantly higher in inducible group (p < 0.05). Mortality was not different in 3 groups compared with no VT/VF group. We found that monomorphic VT group had significantly higher MACE as compared to others and also predicted recurrence of VT and AICD shock and showed a trend towards significance for prediction of mortality. Inducible patients on AICD had mortality similar to noninducible group. Conclusion: Induction of monomorphicVT/polymorphicVT with 3extrastimuli is associated with a higher number of MACE events on follow up. Induction of monomorphicVT predicts recurrence of VT/ICD shock.

Prior statin use and the incidence of in-hospital arrhythmia in acute coronary syndrome: A systematic review and meta-analysis

Background: The benefit of prior statin use to reduce the incidence of arrhythmia in acute coronary syndrome (ACS) is still a matter of debate. Statins have multiple pleiotropic effects, which may reduce the incidence of in-hospital arrhythmia. A systematic review and meta-analysis were performed to evaluate prior statin use and the incidence of in-hospital arrhythmia in ACS. Methods: This systematic review was conducted as per the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). We performed a literature search through Pubmed, Proquest, EBSCOhost, and Clinicaltrial.gov. A random-effect model was used due to moderate heterogeneity. Quality assessment was performed using Newcastle Ottawa Scale. Sensitivity analysis was performed by using leave one or two out method. PROSPERO registration number: CRD42022336402. Results: Nine eligible studies consisting of 86,795 patients were included. A total of 22,130 (25.5%) patients were in statin use before the index ACS event. The prevalence of old myocardial infarction, heart failure, hypertension, diabetes mellitus, and chronic renal failure and concomitant treatment with aspirin, clopidogrel, and beta blocker was higher in the prior statin group compared to no previous statin. Overall, prior statin use was associated with a significantly lower incidence of in-hospital arrhythmia during ACS compared to no previous statin (OR 0.60; 95% CI 0.49e0.72; P < 0.00001; I2 ¼ 54%, Pheterogeneity ¼ 0.03). In subgroup analysis, previous statin use reduced the incidence of atrial fibrillation or atrial flutter (OR 0.64; 95% CI 0.43e0.95; P ¼ 0.03; I2 ¼ 73%, P-heterogeneity ¼ 0.01) and ventricular tachycardia or ventricular fibrillation (OR 0.57; 95% CI 0.49e0.65; P < 0.00001; I2 ¼ 8%, Pheterogeneity ¼ 0.35). Conclusions: Based on aggregate patient data, prior statin use may reduce the incidence of in-hospital arrhythmia during ACS, particularly atrial fibrillation or atrial flutter and ventricular tachycardia or ventricular fibrillation.

A study of serum magnesium levels in acute myocardial infarction and its association with clinical outcome

Background: Cardiovascular disease is one of the leading causes of mortality, morbidity, and increased health-care cost. Magnesium has been implicated in the pathogenesis of acute myocardial infarction (AMI) and its complications. Magnesium ions are considered essential for the maintenance of functional integrity of myocardium. The serum magnesium concentration was found to have great significance in AMI. The present study was undertaken to evaluate the prognostic value of serum magnesium in AMI. Aim and Objectives: The aim of the study was (1) to evaluate serum magnesium levels in patients of AMI on 1st and 7th day post-myocardial infarction and (2) to evaluate validity of serum magnesium as prognostic indicator of Ami. Materials and Methods: This observational cross-sectional study was conducted in the Medicine Department, Guru Nanak Dev Hospital attached to Govt. Medical College, Amritsar. A total of 40 patients of AMI were enrolled in this study. Serum magnesium levels were done for all the patients and its correlation with clinical outcome was observed. Results: On day 1, mean serum magnesium levels in patients with ST-segment elevation myocardial infarction were 1.638 ± 0.19 whereas mean serum magnesium levels in patients with Non-ST-segment elevation myocardial infarction were 2.315 ± 0.321. Mean serum magnesium levels in patients with arrhythmias were 1.73 ± 0.35 on day 1 and 2.14 ± 0.25 on day 7 (P < 0.05). Mean serum magnesium levels at day 1 in patients having mortality are 1.452 ± 0.078 as compared to 2.105 ± 0.399 in rest of surviving patients. It was inferred from this study that patients with AMI with low serum magnesium levels are more prone to develop complications such as arrhythmias and death as compared to patients of AMI with normal serum magnesium levels. Conclusion: Magnesium is an underestimated cation and has been implicated in the pathogenesis of AMI and its complications. Patients of AMI with low serum magnesium levels are found to be more prone to develop arrhythmias as compared to those with normal serum magnesium levels. Hence, it can be concluded that measurement of serum magnesium level is of prognostic significance in AMI.

Síndrome de Andersen Tawil en una embarazada con alto riesgo de muerte súbita. Reporte de caso / Andersen Tawil syndrome in a pregnant woman at high risk of sudden death

Resumen ANTECEDENTES: El síndrome de Andersen Tawil es una canalopatía multisistémica genética, muy rara, sin alteración cardiaca estructural, heredada de manera autosómica dominante y causada por mutación en el gen KCNJ2. Este síndrome se caracteriza por una triada de parálisis muscular periódica, cambios en el electrocardiograma y estructurales corporales. El rasgo distintivo es la taquicardia ventricular bidireccional, las contracciones ventriculares prematuras y raramente taquicardia polimórfica tipo torsade de pointes. En la actualidad se carece de guías para el peri y postparto y para la prevención de arritmias. CASO CLÍNICO: Paciente de 21 años, embarazada, con síndrome de Andersen Tawil diagnosticado a esta edad, con base en los antecedentes de síncope de repetición y debilidad en las extremidades desde los 11 años. Recibía tratamiento con un beta-bloqueador y un desfibrilador automático implantable. La ecocardiografía fetal a las 23 y 33 semanas de gestación reportó una comunicación interventricular apical de 1.6 mm. A las 39 semanas de embarazo se practicó una cesárea electiva, con evolución posoperatoria satisfactoria. El estudio molecular dirigido al recién nacido descartó el síndrome de Andersen Tawil congénito. CONCLUSIÓN: En pacientes con síndromes de arritmia congénita, el embarazo puede ser seguro siempre y cuando un grupo de especialistas esté pendiente para tomar decisiones de atención y tratamiento durante todo el proceso del embarazo y puerperio.

Abstract BACKGROUND: Andersen Tawil syndrome is a very rare genetic multisystemic channelopathy without structural cardiac alteration, inherited in an autosomal dominant manner and caused by mutation in the KCNJ2 gene. This syndrome is characterised by a triad of periodic muscle paralysis, electrocardiogram and body structural changes. The hallmark is bidirectional ventricular tachycardia, premature ventricular contractions and rarely polymorphic torsade de pointes tachycardia. Currently there is a lack of guidelines for peri- and postpartum and arrhythmia prevention. CLINICAL CASE: 21-year-old pregnant patient with Andersen-Tawil syndrome diagnosed at this age, based on a history of repeated syncope and weakness in the extremities since the age of 11. She was being treated with a beta-blocker and an implantable cardioverter defibrillator. Fetal echocardiography at 23 and 33 weeks gestation reported an apical ventricular septal defect of 1.6 mm. Elective caesarean section was performed at 39 weeks of pregnancy, with satisfactory postoperative evolution. Molecular study of the newborn ruled out congenital Andersen-Tawil syndrome. CONCLUSION: In patients with congenital arrhythmia syndromes, pregnancy can be safe as long as it is managed by a group of experts to make decisions and optimise care throughout the pregnancy and postpartum period.

Ressonância Magnética Cardíaca como Ferramenta Diagnóstica Etiológica em Pacientes Recuperados de Morte Súbita Cardíaca ou Arritmias Ventriculares Instáveis / Cardiac Magnetic Resonance as an Etiological Diagnosis Tool in Recovered Sudden Cardiac Death or Unstable Ventricular Arrhythmia Patients

Resumo Fundamento A ressonância magnética cardíaca (RMC) tem relevância diagnóstica crescente em sobreviventes de morte súbita cardíaca (MSC) ou arritmia ventricular instável (AVI) em países desenvolvidos. Objetivo Procuramos avaliar retrospectivamente o papel adicional da RMC em um país em desenvolvimento com poucos recursos disponíveis e que pode direcionar um uso mais eficaz desses recursos. Métodos Foram incluídos sobreviventes de MSC ou AVI admitidos entre 2009 e 2019 em uma instituição acadêmica terciária após a realização de RMC. Dados demográficos, clínicos e laboratoriais foram coletados dos prontuários. Imagens e laudos de RMC foram analisados e o impacto disso no diagnóstico etiológico final foi afirmado. Realizou-se análise descritiva e definiu-se p<0,05 como significativo. Resultados Sessenta e quatro pacientes, 54,9±15,4 anos, sendo 42 (71,9%) do sexo masculino. A maioria dos eventos (81,3%) foi extra-hospitalar e a taquicardia ventricular foi o ritmo mais comum. Medicamentos cardiovasculares foram utilizados anteriormente por 55 pacientes, sendo os betabloqueadores os medicamentos mais utilizados (37,5%). O eletrocardiograma apresentava áreas elétricas inativas em 21,9% e todos apresentavam fibrose na RMC. A média da fração de ejeção do ventrículo esquerdo (FEVE) foi de 44±14%, com 60,9% ≤50% e apenas 29,7% ≤35%. Identificou-se realce tardio com gadolínio em 71,9%, com padrão transmural em 43,8%. A miocardiopatia chagásica foi a etiologia mais comum (28,1%), seguida da miocardiopatia isquêmica (17,2%). Entre 26 sem etiologia previamente identificada, foi possível definir com RMC (15 pacientes - 57%). Conclusão De acordo com estudos anteriores em países desenvolvidos, a RMC foi capaz de aumentar o diagnóstico etiológico e identificar o substrato arritmogênico, permitindo melhor atendimento em metade dos pacientes subdiagnosticados.

Abstract Background Cardiac magnetic resonance (CMR) has an increasing diagnostic relevance in survivors of sudden cardiac death (SCD) or unstable ventricular arrhythmia (UVA) in developed countries. Objective To evaluate retrospectively the additional role of CMR in a developing country where few resources are available, and should be used more effectively. Methods The study included SCD or UVA survivors admitted between 2009 and 2019 at a tertiary academic institution referred to CMR. Demographic, clinical, and laboratory data were collected from the medical records. CMR images and reports were reviewed and their impact on the final etiological diagnosis was determined. A descriptive analysis was performed and p<0.05 established as significant. Results Sixty-four patients, 54.9±15.4 years old, and 42 (71.9%) males. Most events (81.3%) were out of the hospital and ventricular tachycardia was the most common rhythm. Cardiovascular medications were previously used by 55 patients, and beta-blockers were the most used medications (37.5%). Electrocardiogram had electrical inactive areas in 21.9% and all of them had fibrosis at CMR. Mean left ventricular ejection fraction (LVEF) was 44±14%, with 60.9% ≤50% and only 29.7% ≤35%. Late gadolinium enhancement was identified in 71.9%, with a transmural pattern in 43.8%. Chagas cardiomyopathy was the most common etiology (28.1%), followed by ischemic cardiomyopathy (17.2%). Among 26 without a previously identified etiology, CMR could define it (15 patients - 57%). Conclusion In accordance with previous studies in developed countries, CMR was capable of increasing etiological diagnosis and identifying the arrhythmogenic substrate, allowing better care in half of the underdiagnosed patients.

Cardiac Manifestations Associated With Coronavirus Disease: A Case Report

Abstract This study presents a 47-year-old female patient, with a history of diabetes, who contracted SARS-CoV-2 and exhibited cardiovascular complications.

Clinical analysis of perioperative safety and short-term prognosis of non-small cell lung cancer patients with preoperative arrhythmia / 中国胸心血管外科临床杂志

@#Objective    To analyze the perioperative safety and the short-term prognosis of non-small cell lung cancer (NSCLC) patients with preoperative arrhythmia. Methods    The clinical data of NSCLC patients treated in the Department of Cardiothoracic Surgery, the First Affiliated Hospital of Chongqing Medical University from August 2020 to March 2021 were collected and observed. The patients were divided into an arrhythmia group and a control group according to whether there was arrhythmia in the 24 h ambulatory electrocardiogram examination report before operation. The incidence of intraoperative and postoperative cardiovascular events and short-term prognosis were compared between the two groups. Results     A total of 466 patients were included in this study, including 338 patients in the arrhythmia group, 176 males and 162 females, with a median age of 68.0 (63.0, 72.0) years, and 128 patients in the control group, 59 males and 69 females, with a median age of 66.5 (60.0, 72.0) years. A total of 26 patients (7.7%) in the arrhythmia group were placed with temporary pacemakers before operation. There was no significant difference in the incidence of cardiovascular related events between the two groups [100 (29.6%) vs. 28 (21.9%), P=0.096]. The incidence of postoperative arrhythmia events in the arrhythmia group was higher than that in the control group [112 (33.1%) vs. 11 (8.6%), P<0.001]. The average postoperative ICU stay in the arrhythmia group was longer than that in the control group (1.1±0.7 d vs. 1.0±0.6 d, P=0.039). Conclusion    Preoperative arrhythmia does not increase the risk of intraoperative cardiovascular events in NSCLC patients, but increases the incidence of postoperative arrhythmia events and prolongs ICU stay.

Effects of electroacupuncture at Neiguan (PC6) on arrhythmia during myocardial infarction in a rat model of myocardial ischemia-reperfusion / 针灸推拿医学（英文版）

Objective: To observe the effects of electroacupuncture (EA) at Neiguan (PC6) on arrhythmia during acute myocardial ischemia-reperfusion and the expression of connexin 43 (Cx43) in rats. Methods: A total of 40 Sprague-Dawley male rats were used. Ten rats were randomly selected as the blank group, and the remaining 30 rats were randomly divided into a model group and an EA group, with 15 rats in each group. Before modeling, rats in the EA group received one session of EA intervention at bilateral Neiguan (PC6) for 30 min; the other groups were treated with the same grasping and anesthesia for 30 min without intervention. PowerLab physiological recorder was used to record electrocardiograph within 30 min of infarction. After the experiment, cardiac tissue and serum were collected from rats. Hematoxylin-eosin (HE) staining was used to observe the morphological changes of myocardial tissue in the ventricular infarction area of rats in each group. The expression of Cx43 protein in the myocardium of each group was detected by Western blotting (WB). Enzyme-linked immunosorbent assay (ELISA) was used to determine the activity of Na+-K+-ATPase in myocardial tissue and the serum content of endogenous digitalis-like factor (EDLF) in rats. Results: There was no statistical difference in arrhythmia score between the EA group and the model group, but the total duration and average duration of arrhythmia in the EA group were decreased (P<0.01). HE staining showed that compared with the blank group, myocardial cells in the model group were disorganized and seriously damaged. The pathological changes in the EA group were similar to those in the model group, but the damage was relatively minor. The results of WB showed that compared with the blank group, the Cx43 expression in myocardial tissue of the model group was decreased (P<0.01); compared with the model group, the Cx43 expression in the EA group was increased (P<0.01); compared with the blank group, the Na+-K+-ATPase activity in myocardial tissue of the model group was significantly decreased (P<0.01); compared with the model group, the Na+-K+-ATPase activity in the EA group was increased (P<0.01). ELISA results showed that compared with the blank group, the serum EDLF content in the model group was significantly increased (P<0.01); compared with the model group, the EDLF content in the EA group was decreased (P<0.01). Conclusion: EA at Neiguan (PC6) can delay and reduce the onset of arrhythmia during myocardial infarction in the rat model of myocardial ischemia-reperfusion. Its mechanism of action may be related to the regulation of the Cx43 expression in myocardial tissue, improvement of the activity of Na+-K+-ATPase in myocardial tissue, and increase in the content of serum EDLF.

Intraoperative management of potentially fatal arrhythmias after anesthesia induced by severe hypokalemia: A case report / 北京大学学报(医学版)

Severe hypokalemia is defined as the concentration of serum potassium lower than 2.5 mmol/L, which may lead to serious arrhythmias and cause mortality. We report an unusual case of potentially fatal ventricular arrhythmias induced by severe hypokalemia in a patient undergoing laparoscopic partial nephrectomy in Peking University Third Hospital due to irregular use of indapamide before operation. Indapamide is a sulfonamide diuretic with vasodilative and calcium antagonistic effects, which enhances sodium delivery to the renal distal tubules resulting in a dose-related increase in urinary potassium excretion and decreases serum potassium concentrations. The electrolyte disorder caused by the diuretic is more likely to occur in the elderly patients, especially those with malnutrition or long-term fasting. Hence, the serum potassium concentration of the patients under indapamide therapy, especially elderly patients, should be monitored carefully. Meanwhile, the potassium concentration measured by arterial blood gas analysis is different from that measured by venous blood or laboratory test. According to the previous research, the concentration of potassium in venous blood was slightly higher than that in arterial blood, and the difference value was 0.1-0.5 mmol/L. This error should be taken into account when rapid intravenous potassium supplementation or reduction of blood potassium level was carried out clinically. In the correction of severe hypokalemia, the standard approach often did not work well for treating severe hypokalemia. The tailored rapid potassium supplementation strategy shortened the time of hypokalemia and was a safe and better treatment option to remedy life-threatening arrhythmias caused by severe hypokalemia with a high success rate. Through the anesthesia management of this case, we conclude that for the elderly patients who take indapamide or other potassium excretion diuretics, the electrolyte concentration and the general volume state of the patients should be comprehensively measured and fully evaluated before operation. It may be necessary for us to reexamine the serum electrolyte concentration before anesthesia induction on the morning of surgery in patients with the history of hypokalemia. For severe hypokalemia detected after anesthesia, central venous cannulation access for individualized rapid potassium supplementation is an effective approach to reverse the life-threatening arrhythmias caused by severe hypokalemia and ensure the safety of the patients.

Current status and prospect of preoperative assessment of heart disease risk in liver transplant recipients / 器官移植

With the changes of the disease spectrum of liver transplantation and organ allocation system, more and more patients complicated with cardiovascular complications have entered the waiting list for liver transplantation. However, surgical stress, severe infection and adverse reactions of immunosuppressive drugs will significantly increase the risk of postoperative cardiac complications and affect the short-and long-term survival of the recipients. Therefore, comprehensive evaluation of cardiac structure and function of the recipients before liver transplantation is of significance for improving clinical prognosis of the recipients. In this article, the main causes for the increased risk of heart disease during the perioperative period of liver transplantation, the time and methods of heart disease risk assessment for liver transplant recipients were reviewed, and existing assessment approaches for common heart diseases before liver transplantation were illustrated, aiming to provide reference for further reducing the incidence of heart complications after liver transplantation, improving the survival rates of grafts and recipients and enhancing clinical prognosis.