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.

Effect of ivabradine on ventricular arrhythmias in heart failure patients with reduced ejection fraction

SUMMARY BACKGROUND/INTRODUCTION: Heart failure patients with reduced ejection fraction are at high risk for ventricular arrhythmias and sudden cardiac death. Ivabradine, a specific inhibitor of the If current in the sinoatrial node, provides heart rate reduction in sinus rhythm and angina control in chronic coronary syndromes. OBJECTIVE: The effect of ivabradine on ventricular arrhythmias in heart failure patients with reduced ejection fraction patients has not been fully elucidated. The aim of this study was to investigate the effect of ivabradine use on life-threatening arrhythmias and long-term mortality in heart failure patients with reduced ejection fraction patients. METHODS: In this retrospective study, 1,639 patients with heart failure patients with reduced ejection fraction were included. Patients were divided into two groups: ivabradine users and nonusers. Patients presenting with ventricular tachycardia, the presence of ventricular extrasystole, and ventricular tachycardia in 24-h rhythm monitoring, appropriate implantable cardioverter-defibrillator shocks, and long-term mortality outcomes were evaluated according to ivabradine use. RESULTS: After adjustment for all possible variables, admission with ventricular tachycardia was three times higher in ivabradine nonusers (95% confidence interval 1.5-10.2). The presence of premature ventricular contractions and ventricular tachycardias in 24-h rhythm Holter monitoring was notably higher in ivabradine nonusers. According to the adjusted model for all variables, 4.1 times more appropriate implantable cardioverter-defibrillator shocks were observed in the ivabradine nonusers than the users (95%CI 1.8-9.6). Long-term mortality did not differ between these groups after adjustment for all covariates. CONCLUSION: The use of ivabradine reduced the appropriate implantable cardioverter-defibrillator discharge in heart failure patients with reduced ejection fraction patients. Ivabradine has potential in the treatment of ventricular arrhythmias in heart failure patients with reduced ejection fraction patients.

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.

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.

Clinical Evidence of Oral Chinese Patent Medicines in Treatment of Cardiac Arrhythmia： A Scoping Review / 中国实验方剂学杂志

ObjectiveTo review the drug information and research progress on oral Chinese patent medicines in the treatment of cardiac arrhythmia to identify existing problems and provide references for follow-up research. MethodChinese patent medicines against cardiac arrhythmia were retrieved from the three major drug catalogues，Yaozh.com，and relevant guidelines with arrhythmia as the retrieval term. The instructions for included Chinese patent medicines were retrieved through Yaozh.com and specific information was extracted. The research articles on Chinese patent medicines included were retrieved from the five databases，and the information meeting the inclusion and exclusion criteria was extracted and displayed in the form of text description and graphs after statistical analysis. ResultSixty-five oral Chinese patent medicines were included in this study，with the main functions of activating the blood and resolving stasis. The average daily cost of medicines was 8.17 yuan，and there were 42 medicines with an average daily cost of less than 10 yuan，showing a moderate medicine cost. A total of 351 research articles on Chinese patent medicines were screened out，including 259 randomized controlled trials （RCTs），16 non-RCTs，eight non-controlled trials，62 systematic reviews，two guidelines，and two expert consensuses. Eighteen types of Chinese patent medicines were involved，whose clinical trials had been conducted in 28 provinces，cities，autonomous regions，and municipalities in China. Wenxin granules and Shensong Yangxin capsules were the top medicines under investigation，accounting for 75.21% of all research articles. Among the included studies，the most common comparison design was Chinese patent medicine combined with western medicine vs western medicine （64.25%）. The outcome evaluation was mainly based on clinical efficacy，symptom efficacy，arrhythmia efficacy，adverse reactions，and heart rate changes. ConclusionThe number of clinical studies of oral Chinese patent medicines against cardiac arrhythmia varies greatly，but traditional Chinese medicine （TCM） syndrome differentiation thinking is less considered in practical application. Due to unstandardized clinical research and low-quality literature，further advancement is required in the future.

Epidemiological characteristics and psycho-psychological factors of senile arrhythmia in Xining area / 公共卫生与预防医学

Objective To understand the epidemiological characteristics and psychological factors of senile arrhythmia in Xining area, and provide theoretical basis for the prevention and treatment of senile arrhythmia. Methods A total of 518 elderly patients treated in the department of Cardiology in Xining area from June 2018 to June 2020 were selected and divided into control group (without arrhythmia) and study group (with arrhythmia) according to whether the patients were complicated with arrhythmia. All subjects underwent 24h electrocardiographic monitoring to record heart rate, heart rate lead electrocardiogram and 24h dynamic electrocardiogram examination. Refer to the patient's medical records for general information, including age, gender, coronary heart disease, hypertension, etc.; Psychological factors such as depression, anxiety, sleep and quality of life were analyzed. The correlation between PSQI score, HAMA-14 score, HAMD-17 score and arrhythmia was analyzed by Pearson correlation analysis. Results Among 518 patients, 305 (58.89%) were complicated with arrhythmia, including 155 males and 150 females, with an average age of 76.15±3.79. Atrial arrhythmia accounted for 38.36% (117/305), sinus tachycardia accounted for 28.52% (87/305). Ventricular arrhythmias accounted for 11.48% (35/305); The incidence of arrhythmia in 70-79 year olds was significantly higher than that in 60-69 year olds (χ2=8.358 , P2=6.801, P2=1.534, P>0.05). The incidence of arrhythmia was significantly higher in patients with hypertension and coronary heart disease (χ2=16.401, χ2=9.772 , P<0.05). There were significant differences in PSQI score, HAMA-14 score, HAMD-17 score between the two groups (P<0.05). Pearson correlation analysis showed that PSQI score, HAMD-14 score and HAMD-17 score were positively correlated with the occurrence of arrhythmia in the elderly population in Xining area, with correlation coefficients r=0.417 , 0.607 , 0.653 (P<0.05). Conclusion The incidence of arrhythmia increases in the elderly population in Xining area, mainly in the rural elderly population, which is associated with depression and anxiety and sleep disorders and other psychological factors. Early detection and early intervention can improve the response to treatment and accessibility.

Risk factors and predictive analysis of hyperkalemia after heart transplantation / 器官移植

Objective To analyze clinical prognosis, risk factors and predictive indexes of hyperkalemia in recipients after heart transplantation. Methods Clinical data of 158 recipients were retrospectively analyzed. According to the serum potassium levels within postoperative 1-year follow-up, all recipients were divided into the normal serum potassium level group (n=83), hyperkalemia group (n=43) and severe hyperkalemia group (n=32). The incidence and prognosis of hyperkalemia after heart transplantation were summarized. The risk factors and predictive indexes of hyperkalemia after heart transplantation were identified. Results The incidence of hyperkalemia and severe hyperkalemia within postoperative 1 year was 47.5%(75/158) and 20.3%(32/158), respectively. In the severe hyperkalemia group, the fatality was 16%(5/32), higher than 8%(7/83) in the normal serum potassium level group and 7%(3/43) in the hyperkalemia group. The mean serum creatinine (Scr) within 6 months before heart transplantation, the final total bilirubin level before heart transplantation, postoperative hemodialysis time, the Scr level and N-terminal pro-brain natriuretic peptide level at postoperative 1 d were the independent risk factors for hyperkalemia following heart transplantation (all P < 0.05). The mean Scr level within 6 months before heart transplantation, postoperative hemodialysis time, and Scr levels at postoperative 1 and 7 d could be used to predict postoperative severe hyperkalemia. Conclusions The recipients with severe hyperkalemia after heart transplantation obtain poor prognosis. The mean Scr level within 6 months before heart transplantation, the final total bilirubin level before heart transplantation, postoperative hemodialysis time, and the Scr level and N-terminal pro-brain natriuretic peptide level at postoperative 1 d are the independent risk factors for hyperkalemia after heart transplantation. Perioperative Scr level and postoperative hemodialysis time may be used to predict the incidence of severe hyperkalemia within 1 year after heart transplantation.

Clinical research progress and mechanism on myocardial injury in hearts from donors with stroke / 器官移植

At present, the heart of donor from donation after brain death are the primary organ sources for heart transplantation. After brain death, severe hemodynamic changes and a series of organ functional changes will occur, thereby leading to the functional damage or even loss of tissues and organs, especially the heart. Intimate relationship and interaction have been found in the physiology and pathophysiology between nervous and cardiovascular systems. After stroke, autonomic nervous disorder, neuroendocrine disorder and intense and persistent inflammatory reaction could be caused by the brain-heart axis reaction, leading to stroke-induced cardiac injuries, such as sympathetic storm, catecholamine storm, inflammatory storm, etc. In this article, research progresses on the mechanism of myocardial injury in heart from donors with stroke and the effect on clinical efficacy and prognosis after heart transplantation were reviewed, aiming to provide reference for clinical practice and subsequent research.

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.