Cardiac Rhythm Disorders Research Articles

Unveiling the mystery of the female heart's rhythm: a look into gender inequalities in electrophysiology.

This review explores gender disparities in cardiac electrophysiology, highlighting differences in the electrical activity of the heart between men and women. It emphasizes the importance of understanding these variances for correct diagnosis and effective treatment of cardiac arrhythmias. Women show distinct cardiac characteristics influenced by sex hormones, affecting their susceptibility to various arrhythmias. The manuscript covers the classification, mechanisms, and management of arrhythmias in women, considering factors such as pregnancy and menopause. By addressing these gender-specific nuances, it aims to improve healthcare practices and outcomes for female patients with cardiac rhythm disorders.

Diagnostic capability of long-term electrocardiographic telemonitoring for detection of heart rhythm disorders

prevalence of cardiac rhythm and conduction disorders is increasing and associated with the growing amount of people of older age groups. The extended use of traditional electrocardiography (ECG) recorders is currently limited due to duration of the investigation, possible skin irritation and withdrawal of consent by the patients. The aim: evaluation of the frequency of arrythmia incidents in adult patients of different ages by assessing the patch monitoring results, and the impact of the monitoring duration on the possibility of diagnosis. Materials and methods: study included 1123 patients aged from 18 to 99 (599 women and 524 men), data about whom was collected in 2021-2022. ECG was recorded by the «Mawi Heart patch» – a single-use dual-channel device for continuous ECG recording for up to2 7 days. Results: the average ECG monitoring time was 81,03±18,5 hours or 3,37±0,7 days. The majority of the participants (74,35%) received the continuous 3-day ECG monitoring. Most rhythm disorders were recorded in the first 24 hours, but over the next 2 days, atrial fibrillation (AF) was detected in 7,66%, more often in men (48 participants, p=0,048) and with some differences in age groups. Starting above 50 years of age, the frequency of AF diagnosing on the first monitoring days is decreased and it is significantly statistically lower (61,11%, p<0,05). Three-day ECG monitoring is associated with a higher chance of detecting AF (OR=2,03; 1,53-3,02, p=0,031) regardless of gender, while the 5-day monitoring wasn’t as effective. The prolonging of the monitoring time increased the number of diagnosed supraventricular tachycardia (SVT) cases by 5,53% in men and 8,35% in women. The 3 days of monitoring are associated with a higher chance of SVT detection (OR = 4,18; 3,32–4,95, p=0,009). There is a direct correlation between SVT detection and the older age groups (r=0,53, p<0,05). SVT detection is higher in patients of 71-80 years old (OR = 2,71; 2,35–3,75, p=0,0041), and of 81-99 years (OR = 2,92; 2,56–3,49, p=0,0039). Conclusion: The frequency of arrhythmia detection, in patients referred to long-term patch monitoring, is high both for AF and SVT. The sex and age patterns for the prevalence of the described arrhythmias were statistically confirmed. The use of long-term ECG patch monitoring increases the chance of arrhythmia detection, primarily for older patients.

Arrhythmias in Children with Acute Respiratory Viral Infections: Prevalence and Causes

The article presents literature review about arrhythmias in children with acute respiratory viral infections (ARVI). The search was carried out in such databases as PubMed, CyberLeninka, RSCI, etc. ARVI is the most common infectious disease in children and adults, and it can have severe course and various complications. Arrhythmias can be frequently revealed in children with ARVI, and most of them are transient. Life-threatening cardiac rhythm and conduction disorders (CRCD) may occur more rarely, especially in severe cases. Knowledge and interest in the pathophysiology of viral infections have increased significantly, including CRCD risk factors in ARVI, thanks to the data obtained during the analysis of COVID-19 clinical course and outcome. This review summarizes and analyzes data on CRCD prevalence and arrhythmogenesis causes in ARVI.

Risk Factors for Natural Cause Mortality in Schizophrenia

Schizophrenia is associated with premature mortality from mostly natural causes. Decreased cognitive functioning has been identified as a determinant of mortality in the general population. However, there have been few prospective studies of this issue in persons with schizophrenia. To examine whether lower cognitive functioning is a risk factor for natural cause mortality in schizophrenia. This prospective cohort study included persons with schizophrenia or schizoaffective disorder enrolled between February 1, 1999, and December 31, 2022, at a nonprofit psychiatric system in Baltimore, Maryland. Participants were evaluated using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and other clinical measures. Natural cause mortality. Associations of cognitive function, obesity, tobacco smoking, and medical conditions with natural cause mortality were evaluated using Cox proportional hazards regression models. Of the 844 participants enrolled (mean [SD] age, 39.6 [12.1] years; 533 male [63.2%]), 158 (18.7%) died of natural causes during a median follow-up of 14.4 years (range, 7.0 days to 23.9 years). The most significant factor associated with mortality was lower cognitive functioning as measured by the RBANS (Cox coefficient, -0.04; 95% CI, -0.05 to -0.03; z = -5.72; adjusted P < .001). Additional factors independently associated with mortality included the diagnosis of an autoimmune disorder (hazard ratio [HR], 2.86; 95% CI, 1.83-4.47; z = 4.62; adjusted P < .001), tobacco smoking (HR, 2.26; 95% CI, 1.55-3.30; z = 4.23; adjusted P < .001), diagnosis of chronic obstructive pulmonary disease (HR, 3.31; 95% CI, 1.69-6.49; z = 3.48; adjusted P = .006), body mass index as a continuous variable (HR, 1.06; 95% CI, 1.02-1.09; z = 3.30; adjusted P = .01), diagnosis of a cardiac rhythm disorder (HR, 2.56; 95% CI, 1.40-4.69; z = 3.06; adjusted P = .02), and being divorced or separated (HR, 1.80; 95% CI, 1.22-2.65; z = 2.97; adjusted P = .02). An RBANS score below the 50th percentile displayed a joint association with being a smoker, having an elevated body mass index, and having a diagnosis of an autoimmune or a cardiac rhythm disorder. In this prospective cohort study, lower cognitive functioning was a risk factor for natural cause mortality in schizophrenia. Efforts should be directed at methods to improve cognitive functioning, particularly among individuals with additional risk factors.

Clinical experience of pulmonary vein isolation via single transseptal puncture in atrial fibrillation patients: Comprehensive characterization and follow-up

BackgroundAtrial fibrillation is the most commonly observed cardiac rhythm disorder. Pulmonary vein isolation (PVI) is an effective treatment option to maintain sinus rhythm. This study evaluates the safety, efficacy, clinical outcomes and radiation exposures using a standardized single transseptal puncture (STP)-strategy. MethodsWe analyzed data from patients who underwent our STP-ablation technique with transesophageal echocardiography (TEE) guidance at a university hospital and a regional tertiary health center in Switzerland between January 1, 2017, and May 30, 2022. Collected data included demographics, symptoms, echocardiography results, procedural details, complications and outcomes. Mean follow-up time was 21.4 ± 16 months. ResultsThe study population included 304 patients with a median age of 67 years, who had at least one ablation using our STP-approach. Among these, 248 (82 %) patients underwent de novo PVI with this technique. Ablation was successful in all patients with isolation of all pulmonary veins, with an average procedure duration of 120 min and an average fluoroscopy time of 3 min, resulting in a mean X-ray dose of 252 cGy × cm2. TEE guidance was performed in 235 (95 %) patients. During the first intervention, 17 complications occurred in 13 patients (5 %). After the first PVI, 135 (54 %) patients experienced no recurrence during the follow-up period. The one-year recurrence rate for atrial fibrillation requiring therapy was 30 %. ConclusionOur STP- approach demonstrated comparable success rates to traditional methods, with similar procedural durations, low radiation exposure and a low complication rate. Therefore, this method may offer procedural, economic and safety benefits without compromising efficacy or safety.

Advancing cardiac diagnostics: Exceptional accuracy in abnormal ECG signal classification with cascading deep learning and explainability analysis

Arrhythmias, cardiac rhythm disorders, demand precise diagnosis for effective treatment planning, emphasizing the crucial role of electrocardiogram (ECG) signal interpretation. While deep learning excels in ECG classification, its interpretability remains a challenge. Addressing this issue, our research introduces an innovative approach employing image-based ECG representations and cascading deep neural networks (CDNNs) to enhance arrhythmia detection precision. Initiating with the transformation of 12-lead ECG time-series data, particularly focusing on Lead II, into image-based representations using relative positioning matrices (RPM), this novel conversion captures spatial and temporal information concurrently, enriching the depth of our data analysis. Subsequently, CDNNs play a pivotal role in feature extraction, designed to automatically extract impactful features from image-based ECG representations, providing profound insights into cardiac electrical activity. Extracted features serve as inputs for the subsequent deep neural network for classification. Experimental results on the Shaoxing–Chapman ECG database, encompassing over 10,000 recordings with an 80/10/10 split, 80/20 split, 60/40 split, and 10-fold cross-validation, showcase a remarkable 100% accuracy in distinguishing between seven and four different arrhythmia classes. Incorporating SHapley Additive exPlanations (SHAP) values, our methodology offers comprehensive insights into the model’s decision-making, ensuring interpretability. Additionally, Gradient-weighted Class Activation Mapping (Grad-CAM) aids feature visualization, elucidating key features driving predictions. By amalgamating image-based representation, CDNNs, and interpretability techniques, our research not only attains exceptional classification performance but also boosts model transparency and trustworthiness. These findings hold promise for advancing arrhythmia diagnosis and enhancing interpretability in deep learning-based medical applications.

Anaesthetic management in patients with cardiac implantable electronic devices

Cardiac Implantable Electronic Devices (CIEDs) are special devices which are implanted in to human body to treat various cardiac rhythm disorders and heart failure. Anaesthesiologists are now starting to encounter more patients with CIEDs undergoing various surgeries. Hence, it is of paramount importance to know about these devices and its management peri-operatively. Good communication between the anaesthetist, CIED team and surgeon is essential. Understanding the basic functioning of CIEDs and making a detailed preoperative plan can help anticipate and avoid most of the complications. Knowledge about managing intraoperative complications such as dysrhythmias is essential. All these combined with a vigilant monitoring even in the postoperative period is the key for a successful outcome.

Should Physicians Be Aware of Rhythm Disturbances in Adults with Systemic Autoimmune Diseases and Anti-Ro52 Antibodies? A Cross-Sectional Study.

Objectives: The association between anti-Ro/SSA antibodies and the appearance of cardiac rhythm disorders in adults is discussed. We aim to study this relationship, together with active treatments and comorbidities, and its impact on daily clinical practice in adults with systemic autoimmune diseases (SADs). Methods: This cross-sectional single-center study was conducted in a tertiary hospital between January 2021 and March 2022. A sample of adult patients followed up in the SAD Unit with a diagnosis of a SAD and previously tested for anti-Ro/SSA and anti-La/SSB were recruited. All of them underwent a 12-lead electrocardiogram. Results: 167 patients were included. 90 (53.9%) were positive for anti-Ro60, 101 (60.5%) for anti-Ro52, and 45 (26.9%) for anti-La/SSB; 52 (31.3%) were triple-negative. 84% were women, and the mean age was 59 years (standard deviation 12.8). The most common SAD was primary Sjögren's syndrome (34.8%), followed by systemic lupus erythematosus (24.6%) and rheumatoid arthritis (22.8%). A statistically significant relationship was found between anti-Ro52 positivity and cardiac rhythm disorders (relative risk = 2.007 [1.197-3.366]), specifically QTc prolongation (relative risk = 4.248 [1.553-11.615]). Multivariate regressions showed a significant association, with diabetes mellitus being the most related comorbidity. The association between anti-Ro52 antibodies and atrioventricular conduction disorders was not significant. Conclusions: The presence of anti-Ro52 antibodies in adult patients with SADs is associated with an increased risk of QTc prolongation. Electrocardiographic screening of patients with SAD, anti-Ro52 antibodies, and other risk factors, like diabetes mellitus or QT-prolonging drugs, seems advisable. Those with baseline electrocardiogram abnormalities or additional risk factors should undergo electrocardiographic monitoring.

Ventricular arrhythmias in a child with Marfan syndrome: case report

We present a severe disease progression observed in a 13-year-old patient diagnosed with Marfan syndrome and associated cardiac rhythm disorders, including polymorphic ventricular premature contractions and persistent ventricular tachycardia resistant to a wide range of antiarrhythmic medications. We conducted an analysis of contemporary perspectives on the etiology of ventricular tachyarrhythmias and their impact on the prognosis of patients with Marfan syndrome. Conclusions were drawn regarding the selection of treatment strategies for this specific patient population.

NURSING COUNSELING FOR THE OPTIMIZATION OF THE REMOTE MANAGEMENT OF PATIENTS WITH ILR AFTER CRYPTOGENIC STROKE

Abstract Background ILR is a device used to diagnose and document cardiac rhythm disorders in various clinical contexts including syncope and CS. The ILRs can be remotely monitored through a dedicated system consisting of a fully automatic home monitor or, in the latest generation devices, throughan APP that can be downloaded by the patient on his mobile phone. ILR remote monitoring can be performed by the nurse after acquiring the necessary skills on system functioning and knowledge about heart rhythm disorders. Methods Since 2017, a collaboration between Cardiologists and Neurologists has been established at our hospital providing a shared protocol for the management of patients with CS implanted with an ILR to detect asymptomatic AF. All CS patients referred for ILR implantation at our center received a MEDTRONIC ILR and were equipped with a remote monitoring system. ILR management protocol includes a first phase after the implant, where the nurse carries out patient training and counseling; enters all data in the Medtronic Carelink website, provides the patient with the home monitor, clearly explaining its use at home and, finally, obtains patient informed. Second phase of the protocol includes patient FU management, where the nurse reviews all remote transmissions, identifies any arrhythmic events and contacts by phone the patient to evaluate symptoms and, in case,establish the date for FU. Results Since 2017, 70 pz with CS (mean age:65±9 years,67.24% with CHADS2–VASc Score &amp;gt;=4) underwent ILR implantation.ILR remote monitoring allowed the diagnosis of AF in 27% pz (asymptomatic in 72%), of bradyarrhythmia in 4% and VT in 2%. Patients with arrhythmic diagnoses were contacted for FU in H to set up appropriate intervention. In described care pathway, the training and counselling carried out by nurses after the implant was crucial to establish the relationship of trust between patient and nurse, which significantly improved patient compliance. Conclusions The use of ILR has allowed to detect arrhythmias, even when asymptomatic, in patients affected by CS. In our experience, remote monitoring managed by trained nurses was crucial for the early diagnosis of AF. However, since technology is rapidly evolving, training updates to nurse staff regarding remote monitoring systems are essential to improve the counselling. Teamwork and constant cardiologist–nurse communication proved to be fundamental in offering the best care to these patients.

Expanding the Phenotype of the CACNA1C-Associated Neurological Disorders in Children: Systematic Literature Review and Description of a Novel Mutation.

Background: CACNA1C gene encodes the alpha 1 subunit of the CaV1.2 L-type Ca2+ channel. Pathogenic variants in this gene have been associated with cardiac rhythm disorders such as long QT syndrome, Brugada syndrome and Timothy syndrome. Recent evidence has suggested the possible association between CACNA1C mutations and neurologically-isolated (in absence of cardiac involvement) phenotypes in children, giving birth to a wider spectrum of CACNA1C-related clinical presentations. However, to date, little is known about the variety of both neurological and non-neurological signs/symptoms in the neurologically-predominant phenotypes. Methods and Results: We conducted a systematic review of neurologically-predominant presentations without cardiac conduction defects, associated with CACNA1C mutations. We also reported a novel de novo missense pathogenic variant in the CACNA1C gene of a children patient presenting with constructional, dressing and oro-buccal apraxia associated with behavioral abnormalities, mild intellectual disability, dental anomalies, gingival hyperplasia and mild musculoskeletal defects, without cardiac conduction defects. Conclusions: The present study highlights the importance of considering the investigation of the CACNA1C gene in children's neurological isolated syndromes, and expands the phenotype of the CACNA1C related conditions. In addition, the present study highlights that, even in absence of cardiac conduction defects, nuanced clinical manifestations of the Timothy syndrome (e.g., dental and gingival defects) could be found. These findings suggest the high variable expressivity of the CACNA1C gene and remark that the absence of cardiac involvement should not mislead the diagnosis of a CACNA1C related disorder.

Suprastin (Chloropyramine) Causes Proarrhythmic Deterioration of Excitation Conduction, Depolarization and Potentiates Adrenergic Automaticity in the Pulmonary Veins Myocardium.

A number of pharmacological drugs have side effects that contribute to the occurrence of atrial fibrillation, the most common type of cardiac rhythm disorders. The clinical use of antihistamines is widespread; however, information regarding their anti- and/or proarrhythmic effects is contradictory. In this work, we studied the effects and mechanisms of the potential proarrhythmic action of the first-generation antihistamine chloropyramine (Suprastin) in the atrial myocardium and pulmonary vein (PV) myocardial tissue. In PV, chloropyramine caused depolarization of the resting potential and led to reduction of excitation wave conduction. These effects are likely due to suppression of the inward rectifier potassium current (IK1). In presence of epinephrine, chloropyramine induced spontaneous automaticity in the PV and could not be suppressed by atrial pacing. Chloropyramine change functional characteristics of PV and contribute to occurrence of atrial fibrillation. It should be noted that chloropyramine does not provoke atrial tachyarrhythmias, but create conditions for their occurrence during physical exercise and sympathetic stimulation.

Structure of cardiac rhythm disorders in patients with obesity and associated with it dyslipidemia as an arrhythmogenic factor

Obesity is a global public health problem in the twenty-first century. The most adverse it’s effects are associated with visceral type, with accumulation of epicardial fat, showing high metabolic activity, dysfunction and important role in the development of lipotoxic cardiomyopathy linked with significant morphological and functional myocardial changes, accompanying by high risk of heart rhythm disorders. The aim of the study: to identify structure (frequency and character) of cardiac arrhythmias in men of employable age with visceral obesity, to establish the relationship of arrhythmias with features of the blood lipid spectrum of these patients. Material and methods. 98 men with abdominal obesity and 46 overweight patients were examined. The control group consisted of 40 healthy patients with normal body weight. All the patients were undergone ECG monitoring, echocardiography and analysis of serum lipid levels. Results. The presence of obesity is statistically significantly associated with the risk of supraventricular couplets, frequent ventricular extrasystoles, sinus arrhythmia and atrial fibrillation. The increase in the severity of obesity was accompanied by a tendency to a greater frequency of arrhythmias: in obesity of I degree, the frequency of atrial fibrillation was 12.3%, II–III degree — 21.2%, p = 0.25; frequent ventricular extrasystoles with similar degrees of obesity — 13.8% and 21.1%, respectively. Atrial fibrillation was significantly more often detected against the background of lipid disorders, mainly with a decrease in HDLP. Conclusion. The main type of heart rhythm disturbance in patients with obesity are supraventricular arrhythmias, mainly atrial fibrillation, the frequency of which increases in proportion to the increase in the patient's body weight. Abdominal obesity leads to an increase in ventricular ectopic activity. Dyslipidemia is the one of risk factors for arrhythmias in these patients.

Intracardiac electrophysiology to characterize susceptibility to ventricular arrhythmias in murine models.

Introduction: Sudden cardiac death (SCD) and ventricular fibrillation are rare but severe complications of many cardiovascular diseases and represent a major health issue worldwide. Although the primary causes are often acute or chronic coronary diseases, genetic conditions, such as inherited channelopathies or non-ischemic cardiomyopathies are leading causes of SCD among the young. However, relevant experimental models to study the underlying mechanisms of arrhythmias and develop new therapies are still needed. The number of genetically engineered mouse models with cardiac phenotype is growing, making electrophysiological studies in mice essential tools to study arrhythmogenicity and arrhythmia mechanisms and to test novel treatments. Recently, intracardiac catheterization via the jugular vein was described to induce and record ventricular arrhythmias in living anesthetized mice. Several strategies have been reported, developed in healthy wild-type animals and based on aggressive right ventricular stimulation. Methods: Here, we report a protocol based on programmed electrical stimulation (PES) performed in clinical practice in patients with cardiac rhythm disorders, adapted to two transgenic mice models of arrhythmia - Brugada syndrome and cardiolaminopathy. Results: We show that this progressive protocol, based on a limited number of right ventricular extrastimuli, enables to reveal different rhythmic phenotypes between control and diseased mice. In this study, we provide detailed information on PES in mice, including catheter positioning, stimulation protocols, intracardiac and surface ECG interpretation and we reveal a higher susceptibility of two mouse lines to experience triggered ventricular arrhythmias, when compared to control mice. Discussion: Overall, this technique allows to characterize arrhythmias and provides results in phenotyping 2 arrhythmogenic-disease murine models.

Functional ability of mitochondria and mitochondrial genome polymorphism as factors affecting arrhythmogenesis in chronic coronary artery disease

Aim. To investigate functional state of mitochondria and mitochondrial DNA (mtDNA) polymorphism in coronary artery disease (CAD) patients with life-threatening cardiac rhythm disorders (CRD).Methods. We investigated venous blood samples of 45 patients with uncomplicated CAD and 120 CAD patients with CRD. Oxygen consumption rate of mitochondrias of leukocytes in V3 and V4 states were determined in pyruvate-malate and succinate buffers, as well as in the presence of palmitic acid (PA). In patients with complicated CAD, mtDNA haplogroup and substitutions in gene encoding proteins of the respiratory chain complexes and mitochondrial rRNA were determined. Statistical analysis was performed using Mann-Whitney, Wilcoxon tests and Chi-square test with Yates’ correction.Results. In CAD and CAD with CRD, oxygen consumption rate of intact mitochondria did not different in either pyruvate-malate or succinate buffers. In uncomplicated CAD, PA supplementation increases oxygen consumption rate by mitochondria in both succinate and pyruvate-malate buffers. The majority of patients (41%) with CAD and CRD were carriers of the haplogroup «H» and, in this indicator, the sample did not differ from patients with uncomplicated CAD. However, mtDNA of patients with complicated CAD was characterized by a more frequent combined carriage of two and more missense substitutions in genes of respiratory chain and rRNA.Conclusion. Mitochondria of patients with coronary artery disease and life-threatening cardiac rhythm disorders have reduced functional reserve. The distribution of frequencies of main mtDNA haplogroups of patients with coronary artery disease with life threatening cardiac rhythm disorders corresponds to the population. The mtDNA of such patients is characterized by a high frequency of carriage of combined polymorphisms in gene of electron transport chain proteins and rRNA.

Study of antiarrhythmic activity 2-(n-butylpyrrolidine)-N-(2-bromophenyl)carboxamide hydrochloride

Objective. To study the efficacy of a new derivative 2-(alkylpyrrolidine)-N-(aryl)carboxamide with high antiarrhythmic activity. Materials and methods. To study the antiarrhythmic activity of the compound, the experiment was carried out on models of arrhythmia caused by intravenous administration of aconitine and adrenaline. The effect was estimated by its ability to prevent the onset of arrhythmia, prolong the survival time of the animals or by the duration of an arrhythmia attack. In addition, the electrocardiogram of awake rats was analyzed. The studied compound and the comparison drug (lidocaine) were injected to the animals intravenously in effective antiarrhythmic doses. Results. In aconitine arrhythmia 2-(n-butylpyrrolidine)-N-(2-bromophenyl) carboxamide hydrochloride provides statistically significant limitation of the duration of arrhythmia attacks in experimental animals (1.7 times) in comparison with the control and also reduction of arrhythmia duration in comparison with lidocaine (2.5 times); besides, this compound guarantees animals’ survival in 100 % of cases. When causing arrhythmia by adrenaline administration, the compound does not prevent the occurrence of cardiac rhythm disorder. The electrocardiogram readings of animals do not change significantly. Conclusions. 2-(n-butylpyrrolidine)-N-(2-bromophenyl) carboxamide hydrochloride (compound K-23) shows visible activity in models of arrhythmia caused by administration of aconitine and calcium chloride, which may indicate its ability to impede the sodium flow through the cell membrane by slowing depolarization of cardiomyocytes. Since the compound studied, demonstrates high antiarrhythmic activity without changing the ECG readings, the drug created on its basis may be effective.

Potential role of mitochondrial dysfunction in arrhythmogenesis in coronary artery disease

Introduction. Coronary artery disease (CAD) continues to be the most common pathology in the structure of cardiovascular diseases over the past decades, both in Russia and around the world. In the normal condition, the mitochondria of all body cells have the same function capabilities due to the carriage of the same genome. Therefore, it is possible to assess the respiration activity of cardiomyocyte mitochondria by the respiration of mitochondria from peripheral blood leukocytes.Aim: To compare respiratory activity of mitochondria of peripheral blood leukocytes in patients diagnosed with coronary artery disease and coronary artery disease with developed cardiac rhythm disorders (CRD).Material and methods. The studied groups included 45 patients with CAD without CRD and 39 patients with CAD complicated by CRD. Mitochondria were isolated from peripheral blood leukocytes by differential centrifugation. The rate of oxygen loss in pyruvate-malate and succinate incubation buffers was measured when isolated mitochondria were introduced, as well as when palmitic acid was added to the medium. Oxygen consumption rate for the V3 (active phosphorylating) and V4 (nonphosphorylating) metabolic sates was determined, and on their basis respiratory control coefficient was calculating using the formula V3/V4. Statistical data processing was carried out using STATISTICA 13.0 software.Results. Oxygen consumption rate in mitochondria of patients with uncomplicated CAD and CAD with CRD had no significant differences in either pyruvate-malate or succinate buffers. When palmitic acid was added to the incubation medium, the mitochondria of CAD patients without CRD significantly increased oxygen consumption rate in both incubation media. Mitochondria of CAD patients with CRD did not change oxygen consumption rate in both metabolic states after the addition of palmitic acid in incubation media.Conclusion. On the basis of the data obtained, it can be concluded that the function capabilities of mitochondria in the complicated course of CAD has been exhausted, which manifests itself in the inability to increase ATP synthesis in response to the introduction of additional substrates.

Autoimmunity and Biological Therapies in Cardiac Arrhythmias

Autoimmune (AI) diseases have a notable rise globally, affecting up to 9.4% of the global population. Cardiac involvement is not unusual in AI diseases, leading to arrhythmias through many pathophysiological mechanisms like myocardial inflammation, fibrosis, and autoantibodies targeting critical cardiac structures, leading to cardiac rhythm disorders. This review focuses on the role of autoantibodies in arrhythmias in diseases like sarcoidosis, lupus, rheumatoid arthritis, scleroderma, and others, highlighting new findings about autoantibodies against critical structural myocardial components. On the other hand, the review describes the AI association with conditions such as sinus bradycardia, atrioventricular blocks, inappropriate sinus tachycardia, atrial fibrillation, ventricular tachycardia, and sudden cardiac death, describing those processes. Emerging biomarkers indicative of inflammation, fibrosis, and autoimmunity that can predict arrhythmia risk are examined. The review also explores the field of managing cardiac arrhythmias with alternative cell therapy approaches that target gene substrate as a promising way to transfer, silence, and edit cellular disorders associated with arrhythmia generation that may help treat these conditions in the future.

Cardiac rhythm disorders in hospitalised patients with moderate and severe left ventricular dysfunction - A Cross Sectional Observational study.

Cardiac rhythm disorders in hospitalised patients with moderate and severe left ventricular dysfunction - A Cross Sectional Observational study.

Disorders of cardiac conduction and rhythm in patients with rheumatoid arthritis

The article presents data on the frequency and features of the development of various cardiac conduction and rhythm disorders in patients with rheumatoid arthritis, the mechanisms of development of these disorders, and discusses the role of inflammation, atrial remodeling, dysfunction of the autonomic nervous system, activation of the renin-angiotensin system, endothelial dysfunction and other factors.