Rhythm Disturbances Research Articles

Role of Artificial Intelligence-Assisted Decision Support Tool for Common Rhythm Disturbances: A ChatGPT Proof-of-Concept Study

Role of Artificial Intelligence-Assisted Decision Support Tool for Common Rhythm Disturbances: A ChatGPT Proof-of-Concept Study

Exercise improves muscle mitochondrial dysfunction-associated lipid profile under circadian rhythm disturbance.

We investigated whether endurance exercise training (EXT) ameliorates circadian rhythm (CR)-induced risk factors by improving skeletal muscle (SKM) mitochondrial biogenesis, reducing oxidative stress, and modulating apoptotic protein expression. We distinguished between regular and shift workers using the National Health and Nutrition Examination Survey (NHANES) and investigated the health problems caused by shift work (CR disturbance) and the potential therapeutic effects of exercise. In our animal study, 36 rats underwent 12 weeks of CR disturbance, divided into regular and irregular CR groups. These groups were further split into EXT (n = 12) and sedentary (n = 12) for an additional 8 weeks. We analyzed SKM tissue to understand the molecular changes induced by CR and EXT. NHANES data were analyzed using SAS 9.4 and Prism 8 software, while experimental animal data were analyzed using Prism 8 software. The statistical procedures used in each experiment are indicated in the figure legends. Our studies showed that CR disturbance increases dyslipidemia, alters circadian clock proteins (BMAL1, PER2), raises apoptotic protein levels, and reduces mitochondrial biogenesis in SKM. EXT improved LDL-C and HDLC levels without affecting muscle BMAL1 expression. It also enhanced mitochondrial biogenesis (AMPK, PGC-1α, Tfam, NADH-UO, COX-I), antioxidant levels (Catalase, SOD1, SOD2), and apoptotic protein (p53, Bax/Bcl2) expression or activity in SKM. We demonstrated that shift work-induced CR disturbance leads to dyslipidemia, diminished mitochondrial biogenesis, and reduced antioxidant capacity in SKM. However, EXT can counteract dyslipidemia under CR disturbance, potentially lowering the risk of cardiovascular disorders.

Circadian rhythm disruption: a potential trigger in Parkinson’s disease pathogenesis

Parkinson’s disease (PD) is a neurodegenerative disease characterized by the gradual loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc), abnormal accumulation of α-synuclein (α-syn), and activation of microglia leading to neuroinflammation. Disturbances in circadian rhythm play a significant role in PD, with most non-motor symptoms associated with disruptions in circadian rhythm. These disturbances can be observed years before motor symptoms appear and are marked by the emergence of non-motor symptoms related to PD, such as rapid eye movement sleep behavior disorder (RBD), restless leg syndrome (RLS), excessive daytime sleepiness (EDS), depression and anxiety, changes in blood pressure, gastrointestinal dysfunction, and urinary problems. Circadian rhythm disruption precedes the onset of motor symptoms and contributes to the progression of PD. In brief, this article outlines the role of circadian rhythm disruption in triggering PD at cellular and molecular levels, as well as its clinical manifestations. It also explores how circadian rhythm research can contribute to preventing the onset and progression of PD from current and future perspectives.

Перипартальна кардіоміопатія: сучасні можливості ведення пацієнток із важкою серцевою недостатністю

Peripartum cardiomyopathy (PCMP) is a cardiomyopathy with impaired LV systolic function that develops in pregnant women or in the first months after childbirth. Clinical manifestations can vary from mild or moderate to severe symptoms of heart failure with significant functional limitation and high mortality. The mechanisms of PCMP development are unknown, and there is no specific treatment. In the article, we wanted to demonstrate our own experience of managing a patient with severe PCMP, the course of which was complicated by heart rhythm disturbances, the development of cardiogenic shock and pulmonary edema. This clinical example will highlight basic information about the etiology, pathogenesis, prevention and treatment of PCMP at the current stage.

Orexinergic modulation of chronic jet lag-induced deficits in mouse cognitive flexibility.

Cognitive flexibility and working memory are important executive functions mediated by the prefrontal cortex and can be impaired by circadian rhythm disturbances such as chronic jet lag (CJL) or shift work. In the present study, we used mice to investigate whether (1) simulated CJL impairs cognitive flexibility, (2) the orexin system is involved in such impairment, and (3) nasal administration of orexin A is able to reverse CJL-induced deficits in cognitive flexibility and working memory. Mice were exposed to either standard light-dark conditions or simulated CJL consisting of series of advance time shifts. Experiment (1) investigated the effects of a mild CJL protocol on cognitive flexibility using the attentional set shifting task. Experiment (2) used a stronger CJL protocol and examined CJL effects on the orexin system utilizing c-Fos and orexin immunohistochemistry. Experiment (3) tested whether nasal orexin application can rescue CJL-induced deficits in cognitive flexibility and working memory, the latter by measuring spontaneous alternation in the Y-maze. The present data show that CJL (1) impairs cognitive flexibility and (2) reduces the activity of orexin neurons in the lateral hypothalamus. (3) Nasal administration of orexin A rescued CJL-induced deficits in working memory and cognitive flexibility. These findings suggest that executive function impairments by circadian rhythm disturbances such as CJL are caused by dysregulation of orexinergic input to the prefrontal cortex. Compensation of decreased orexinergic input by nasal administration of orexin A could be a potential therapy for CJL- or shift work-induced human deficits in executive functions.

Holter monitoring in neuromuscular disorders: frequency and importance in clinical management

Abstract Introduction Cardiac involvement is a common manifestation in a variety of neuromuscular disorders (NMD) and initial cardiac manifestations in these patients are often asymptomatic. Hence, regular 24h-Holter monitoring is recommended to identify conduction disturbances and rhythm disturbances. Purpose In this study, we aimed to assess abnormal findings in 24h-Holter monitoring to screen for conduction disturbances and arrhythmias in patients with NMD and evaluate its impact in patients’ treatment. Methods A retrospective single-centre study was conducted including all adult patients with NMD who received a 24h-Holter from January 2013 to September 2023. Results A total of 76 patients with NMD were included, 39 (51.3%) were male, and mean age was 46,3 ± 11,5 years. Most patients were asymptomatic. A total of 220 Holter recording was analysed. An average of 2,9 ± 1,6 Holter recordings per patient was performed. Abnormal Holter results were found in 47 (61,8%) patients, and mainly consisted of conduction disorders such as atrioventricular block in 31 (65,9%) patients. Other abnormalities included atrial fibrillation/flutter in 6 (12,8%) patients, supraventricular tachycardia in 4 (8,5%) patients, and non-sustained ventricular tachycardia in 6 (12,8) patients. Out of the group of the patients with abnormal Holter findings, ten patients had direct clinical treatment consequences, namely implantation of cardiac electronic devices or initiation of anticoagulation therapy. Conclusion In this study, holter findings resulted in relevant clinical treatment consequences in 10 out of 76 patients (13,2%). These results suggest that 24h-Holter monitoring may improve routine cardiac screening in patients with NMD.

Fitness to fly: assessing cardiac disease among Air Force pilots

Abstract Introduction Aviation is a risk activity, particularly in pilots with cardiovascular (CV) disease. The occurrence of acute clinical events during flight may have catastrophic implications, justifying the relevance of cardiologic evaluation in Aviation Medicine. However, the evidence about the impact of CV diseases in this population is scarce. Aim To study the cardiac causes of incapacitation among pilot candidates and pilots of the Portuguese Air Force (PoAF) over a period of 20 years. Methods and results A retrospective analysis of cardiac causes of incapacitation between January 1999 and December 2018 was performed, both in PoAF candidates and pilots. In this period, the overall number of candidates was 2529 and the number of PoAF pilots was 760. Among the candidates, 41% (N=1086) were considered unfit, of which 4% (N=39) due to cardiac causes (all men aged 17-25), namely valvular diseases (N=27) and conduction/heart rhythm disturbances (N=12). Among the pilots, 2% (N=18) were considered unfit, mainly due to cardiac disease (50%; N=9). These pilots considered unfit pilots due to cardiac disease were men with mean age of 47±9 (30-60) years old, all unfit due to acute myocardial infarction, none occurring during flight. Conclusion Cardiac diseases were an uncommon cause of incapacitation among the pilot aviator candidates, but it was the main cause among the pilots of the PoAF during two decades, all due to acute myocardial infarction. Cardiac evaluation in Aviation Medicine is essential, focusing on CV risk stratification and preclinical detection of coronary artery disease.Figure 1

Diagnostic value of aortic valve displacement by tissue tracking for identification of aortic valve stenosis severity

Abstract Background The assessment of aortic stenosis (AS) severity on transthoracic echocardiography (TTE) may be challenging, especially in normal flow, low gradient (NF LG) group with preserved ejection fraction (EF), where reclassification of AS severity after initial TTE was observed in 52% pts (1). Calcifications and fibrosis of valve leaflets result in increased stiffness and impaired mobility, which can be quantified by tissue tracking (TT). TT is an echocardiographic modality that displays longitudinal displacement of selected area by integrating tissue velocity over time. Purpose Assessment of the diagnostic value of aortic valve displacement (AVD) by TT as a test that may increase accuracy of AS severity diagnosis in TTE. Methods 205 pts (aged 71±10 yrs, men 43%) without more than mild aortic regurgitation, mitral or tricuspid valve disease, EF ≤55%, indexed stroke volume (SVI) ≤35 ml/m2, cardiac rhythm disturbances and poor acoustic window were selected out of 842 pts screened for AS in our institution between 2020 and 2023. Based on aortic valve area (AVA) value, moderate (n=51, AVA >1.0 cm2) or severe (n=154, AVA ≤1.0 cm2) AS was diagnosed. In severe AS group, 45 pts were classified as NF LG AS (mean gradient <40 mmHg). Additionally 30 pts (aged 68±10 yrs, men 46%) without abnormalities on TTE entered control group. During TTE in five- and three-chamber views, TT was applied and region of interest was adjusted to cover whole aortic valve (AV) during cardiac cycle. Single loop was analysed with Q-analysis software. The measurement in millimetres (mm) of positive wave representing displacement of AV was performed in both views by two independent echocardiographers (Figure 1). AVD was calculated by summing up results from both views. Receiver-operating characteristic curves for AVD in the whole study group and NF LG AS to diagnose severe AS were plotted. Results AVD was already significantly decreased in moderate AS compared with age- and sex-matched healthy controls, being 22.8±2.8 mm and 24.3±2.1 mm respectively (P=0.01). In pts with severe AS, AVD was further significantly reduced compared to moderate AS pts, being 19.3±3.2 mm (P<0.0001). In the whole study group, AVD with a cut-off point <19.6 mm provided 55.8% sensitivity but 96.1 % specificity to diagnose severe AS (Figure 2B). In pts with NF LG AS, AVD with a cut-off point <20.6 mm provided 71.4% sensitivity and a specificity of 79.6% (Figure 2A). Intraclass correlation coefficient of 0.87; 95% CI (0.84–0.89) indicated good interobserver reproducibility of AVD measurement. Conclusions Aortic valve displacement by tissue tracking in TTE is a valuable, new echocardiographic tool for identification of AS severity and may improve diagnostic accuracy of AS severity in NF LG AS.Figure 1Figure 2

Implantable loop recorders in children and adolescents with Brugada syndrome: the YoungBruLoop study

Abstract Background Young (<18 years of age) patients with Brugada syndrome (BrS) are often underrepresented in BrS studies and their management, especially related to syncopal episodes, remains unclear. Purpose To describe the arrhythmia prevalence and clinical implication derived from continuous rhythm monitoring by implantable loop recorder (ILR) among patients younger than 18 years of age, and to assess the etiology behind syncope of undetermined origin. Methods A total of 147 BrS patients with ILR were enrolled in 12 international centers and divided into pediatric (age <12 years; n=77, 52%) and adolescents (age 13 to 18 years; n=70, 48%). Results Mean age was 11.3 years (36.1% females, 21.1% spontaneous type I ECG). Forty-six patients (31.2%) underwent ILR implant due to syncope. Over a median follow-up of 3.6 years, an arrhythmic event was recorded in 22.4% of patients and in the vast majority of cases it was of non-ventricular origin (44% atrial, 47% bradyarrhythmias). Predictors of arrhythmias at univariate Cox Regression analysis were spontaneous type I ECG (HR 2.1 - 95%C.I. 1.1-4.1), history of syncope (HR 3.1 - 95%CI 1.5-6.3) and age >12 years (HR 2.0 - 95%C.I. 1.0-3.3). Ventricular arrhythmias occurred in 4 patients, all with spontaneous BrS, and were related to fever in half of cases. In patients with recurrent syncope, the prevalence of truly arrhythmic syncope was 17.8%, and it was due to brady-, atrial- and ventricular arrhythmias in 40%, 20% and 40% of cases, respectively. Conclusions Continuous rhythm monitoring with ILRs in BrS pediatric patients detects a broad range of heart rhythm disturbances including life-threatening arrhythmias. Ventricular arrhythmias occur predominantly in patients with spontaneous type I ECG and in half of cases are fever-related. Despite the young age, brady- and atrial arrhythmias are overall frequent and represent the cause of arrhythmic syncope in 60% of patients. Young BrS patients with syncope of undetermined origin may benefit from ILR implant.

Characteristics of fatal COVID-19 among pregnant women admitted to hospitals in Kazakhstan

Abstract Background The factors contributing to the fatal outcome of COVID-19 in pregnant women remain not entirely clear. We compared the prevalence rates of comorbidities and laboratory test results in pregnant survivors and non-survivors. Methods This retrospective study relied on clinical and laboratory data obtained from medical records of pregnant women with COVID-19 admitted to three hospitals of the Republic of Kazakhstan from 16.07.2021 to 31.01.2022. Overall, we obtained data on 157 pregnant women with COVID-19, of whom 95.9 % survived and 4.1 % died in the hospitals. Results Arterial hypertension was present in 50% of non-survivors vs. 7.9% of survivors (P = 0.001), diabetes mellitus was diagnosed in 16.7% of non-survivors vs. 2.3% of survivors (P = 0.044), and the rate of hyperglycemia was 40% and 7.2%, respectively (P = 0.009). Heart rhythm disturbance was present in 50% of non-survivors vs. 6.4% of survivors (P < 0.001), and already at the time of admission to the hospital, the non-survivors had significantly higher heart and respiratory rates. Laboratory tests showed that non-survivors had higher erythrocytes sedimentation rate, C-reactive protein, leukocyte count, and D-dimer levels (P = 0.001, P < 0.001, P = 0.038, P = 0.014, respectively). The creatinine level was within the normal range in both study groups, but it was relatively higher in the deceased pregnant women (71.3; IQR: 66-251.75) vs. 52; IQR: 43-63; P = 0.001). Finally, a higher proportion of those who died presented with abnormal chest CT as compared with the survivors (33.3% vs. 4.2%, P < 0.001). Conclusions The deceased had a higher rate of comorbidities. Given the vulnerability of pregnant women to COVID-19, it is essential to plan a prospective study to provide insights into the factors that contribute to severe COVID-19 outcomes in pregnant women. Key messages • Determining risk factors for fatal COVID-19 is crucial for effective medical care of pregnant women. • Identifying potential risk factors of fatal COVID-19 among pregnant women could help inform public health policies and clinical guidelines.

Molybdenum temporary epicardial pacing wires: function and biodegradation

Abstract Cardiac pacing with temporary epicardial pacing wires (TEPW) is used to treat rhythm disturbances after cardiac surgery. Wires typically begin to fail around postoperative day four and are extracted. Occasionally, TEPW cannot be mechanically removed, have to stay in the thorax and may rarely cause serious complications like migration and infection. We aim to develop novel, bioresorbable TEPW which will dissolve over time, even if postoperative removal is unsuccessful. We manufactured prototypical braided molybdenum (Mo) leads (16 Mo wires of 40 µM diameter each, length 18 cm for ex vivo, 7.5 cm for in vivo experiments) coated with the biodegradable polymers poly(lactide-co-glycolic acid) (PLGA, inner coating) and polycaprolactone (PCL, outer coating) for shaping and electrical insulation. Mo electrodes showed similar pacing and sensing properties to conventional steel electrodes (Osypka) in Langendorff-perfused rat hearts, even with somewhat lower stimulation thresholds. In artificial body fluid at 37°C, the polymer-coated Mo electrodes dissolved at a rate of 1.6 ± 0.3 µg/cm2·d (n = 5) compared to uncoated electrodes with 30.3 ± 0.8 µg/cm2·d (n = 4, p < 0.001). Assessing apoptosis and necrosis in human cardiomyocytes and cardiac fibroblasts, we detected no toxicity at Mo concentrations up to 0.52 mM. To test the in vivo properties of Mo TEPW, we sutured them epicardially onto the anterior wall of the heart of female Wistar rats, led them out of the thorax through an intercostal space and placed them in a subcutaneous pocket. We tested electrophysiological properties directly after implantation and after different time periods. Mo TEPW showed similar pacing and sensing properties directly upon implantation and after 2 weeks, with only impedance and slew rate of the sensed R-wave decreasing time-dependently. After one month, all but one pair of Mo electrodes were mechanically broken at their exit from the thorax, the site of assumedly highest mechanical stress. Progressive Mo degradation led to multiple fragmentation of the Mo TEPW after 6 months. The conventional steel TEPW we used as control had similar electrical properties directly after implantation, after 2 weeks and one month without signs of broken electrodes. After 6 months, all but one pair of steel electrodes were mechanically broken at their thorax exit site. Comparing urinary Mo concentration of Mo TEPW treated rats to controls, we saw similar values of 1.9 ± 1.9 µM (n = 6) vs. 0.6 ± 0.2 µM (n = 5, n.s.) after one week. In contrast, we saw a significant increase of 12.1 ± 9.7 µM (n = 5) vs. 1.0 ± 0.9 µM (n = 5, p < 0.001) after 6 months, reflecting the degradation progress. We demonstrate that Mo TEPW are a feasible option for epicardial pacing in vivo for up to 2 weeks and observed the progress of Mo degradation up to 6 months. These findings represent an important step in the development of bioresorbable TEPW as a novel and even safer approach to temporary epicardial pacing.Graphical AbstractIn Vivo Degradation Progress

Dynamics of changes in heart rate, ST segment and T-wave on patients with ventricular rhythm disturbances on the background of type 2 diabetes mellitus according to the results of 24-hour cardiac monitoring

The aim of the study was to analyze the dynamics of heart rate, assess the morphogenesis of the ST segment and T wave in patients with ventricular arrhythmias associated with type 2 diabetes mellitus (type 2 DM) based on the results of daily cardiac monitoring against the background of two regimens of metabolitotropic treatment. The study included 133 patients with type 2 DM with ventricular arrhythmias. The inclusion criteria for the study were: moderately severe type 2 diabetes in the stage of sub-/compensation on the background of combined glucose-lowering therapy without insulin, the presence of ventricular arrhythmias of classes III–V according to Lown B. and Wolf M. (1971). By random sampling, patients were randomized into 3 observation groups, statistically homogeneous in age, sex, duration of the diabetic syndrome, classes of ventricular arrhythmias. Patients of the 1st group (n = 44) received amiodarone and beta-blocker. Patients of the 2nd group (n = 45) received the same antiarrhythmic treatment, but in combination with meldonium for 3 consecutive months with the next 3-month course repeated after 6 months. Representatives of the 3rd group (n = 44) received treatment with amiodarone, beta-blocker and trimetazidine of the same duration. 24-hour ECG monitoring was performed at baseline, 3 months later, and 1 year later. Statistica 6.0 software was used for statistical processing. The examination revealed tachycardia syndrome and signs of pain and painless myocardial ischemia. It has been established that ventricular arrhythmias in type 2 DM are of a secondary nature, largely dependent on ischemic manifestations. Trimetazidine compared with meldonium showed a greater anti-ischemic effect, which made it possible to obtain a better antiarrhythmic effect. Trimetazidine is considered as one of the justified components of the treatment of ventricular arrhythmias of ischemic origin in patients with type 2 DM.

Ventricular arrhythmias occurring in myocardial infarction patients with acute ST-segment elevation within the first 24 hours after primary percutaneous coronary intervention and their prognostic value

Reperfusion therapy in myocardial infarction patients with acute ST-segment elevation significantly reduced the frequency of ventricular tachycardia and ventricular fibrillation, however, such arrhythmias still occur in 6-8% of patients, posing a threat to their lives.The aim of the study was to determine the nature of ventricular arrhythmias occurring in myocardial infarction patients with acute ST-segment elevation within the first 24 hours after primary percutaneous coronary intervention, and their prognostic value regarding the development of complications during the inpatient treatment phase. The study involved 82 individuals (mean age: 62,4±10,2 years; male: 69,23 (58,6-78,92)%, female: 30,77 (21,08-41,4)%). Within 24 hours after the infarct-related artery stenting, all patients underwent a 24-hour Holter ECG monitoring. The course of the disease was analyzed based on the presence of risk factors such as hypertension, diabetes mellitus, past COVID-19, and obesity. Ventricular rhythm disturbances were represented mainly by premature contractions. They occurred significantly more frequently in patients with arterial hypertension (883,71 (96,0; 986.0); p=0,02; p=0,03; p=0,02, compared to patients with a history of COVID-19, diabetes, and obesity, respectively) and in those with past COVID-19 (711,3 (125,0; 846,5); p=0,01; p=0,04, compared to indi­viduals with diabetes and obesity, respectively). Isolated premature ventricular complexes, pairs, triplets were recorded, and in individuals with arterial hypertension and past COVID-19 “runs” of ventricular extrasystoles and episodes of nonsustained monomorphic and even polymorphic ventricular tachycardia, such as Torsades de Pointes, (under the condition of combined risk factors) were noted; predominantly in these patients during the hospital phase such сom­plications as ventricular fibrillation and asystole,with sudden cardiac arrest developed. The obtained results is an evidence of electrical myocardial instability and indicate that myocardial infarction patients with acute ST-segment elevation, in addition to myocardial revascularization, require optimization of pharmacological treatment. The use of intravenous beta-blockers as part of complex treatment prevented the occurrence of life-threatening ventricular arrhythmias during the inpatient treatment phase.

Effects of the Fungicide Prothioconazole on Lipid Metabolism in Mice: Whitening Alterations of Brown Adipose Tissue.

With considerable concerns about the associations between metabolic disorders and agricultural biocides, there are scattered data suggesting that the triazole fungicide prothioconazole (PTC) at lower doses than the no observed adverse effect level of 5000 μg/kg/d possibly has the potential to disrupt glycolipid metabolism in mammals. Here, we investigated the effects of 50, 500, and 5000 μg/kg/d of PTC on glycolipid metabolism in mice following 8 weeks of administration via drinking water, with specific attention on brown adipose tissue (BAT) and white adipose tissue (WAT) in addition to the liver. We found that along with the increased serum triglyceride level in the 5000 μg/kg/d group, small fatty vacuoles occurred in livers in all treatment groups, indicating lipid accumulation. No change in WAT was observed, but PTC caused BAT whitening, characterized by adipocyte hypertrophy, more unilocular adipocytes with enlarged lipid droplets, reduced UCP1 levels, and down-regulated Doi2 expression, and even the dose of 50 μg/kg/d was effective. Transcriptomic analysis revealed immune inhibition and circadian rhythm disturbance in BAT from the 5000 μg/kg/d group, which are in agreement with BAT whitening and inactivation. On employing the C3H10T1/2 cells in vitro, we found that PTC treatment concentration-dependently promoted lipid accumulation in brown adipocytes, along with altered expression of thermogenesis-related and circadian genes. Taken together, our study shows that low doses of PTC caused BAT whitening, calling for much attention to the new target by pollutants.

Early arrhythmia after cardiac surgery in children with congenital heart disease

Objective. To analyze the frequency and risk factors for arrhythmia in children with congenital heart disease in the early period after cardiac surgery. Materials and methods. A retrospective analysis of the incidence and risk factors for arrhythmia in 285 children who underwent cardiac surgery in the Department of Surgical Treatment of Congenital Heart Diseases in Newborns and Young Children at the Amosov National Institute of Cardiovascular Surgery of the National Academy of Medical Sciences of Ukraine for the period from 2021 to 2023 was performed. There were 202 children under the age of 18. Results. In the early postoperative period, heart rhythm disturbances occurred in 53 (26.2%) of 202 patients: 28 had supraventricular tachycardia, 16 had bradyarrhythmia (atrioventricular block), 6 had ventricular tachycardia, and 3 had nodal ectopic tachycardia. It was found that plastic surgery of the interventricular and atrial septal defect in isolation or in combination with interventions for other defects (Fallot's tetrad, transposition of the great vessels, atrioventricular communication) and bidirectional and total cavopulmonary anastomoses are associated with a high risk of arrhythmia. Statistically significant (p < 0.05) risk factors for arrhythmia were: lactate level of more than 2 mmol/L, duration of cardiopulmonary bypass more than 185 minutes, duration of aortic clamping more than 67 minutes. Conclusions. Arrhythmia often complicates the course of the early period after cardiac surgery in children and requires timely and correct action. Prolonged cardiopulmonary bypass, aortic constriction, and lactatidosis are risk factors for arrhythmia. Plastic surgery of the interventricular and atrial septal defects, as well as palliative reconstructive heart surgery, are associated with frequent cardiac arrhythmias in the early postoperative period.

Syncope as a clinical presentation of cardiac lymphoma: a case report

Primary cardiac lymphoma, an extremely rare type of B-cell non-Hodgkin lymphoma, has an incidence of approximately 0.02-2% among malignant cardiac tumors. It is frequently associated with manifestations such as cardiac rhythm disturbances, refractory pericardial effusion and cardiac masses. Definitive diagnosis is achieved by biopsy, being essential to rule out hematogenous dissemination with PET-CT. The literature indicates a predominance of right chamber involvement and survival that varies significantly according to left ventricular involvement and the presence of arrhythmias. Therapeutic options are not well defined, but chemotherapy such as R-CHOP has shown efficacy, although the prognosis is generally poor due to complications such as disease progression, arrhythmias and sepsis. This case underscores the importance of considering cardiac lymphoma in patients with unexplained cardiac symptoms, highlighting the need for a multidisciplinary and specific diagnostic and therapeutic approach.

Beta-adrenergic reactivity of erythrocyte membranes in adolescents with supraventricular and ventricular arrhythmias before and after radiofrequency ablation

Aim. To evaluate β-adrenergic reactivity of erythrocyte membranes (β-ARM) in adolescents with ventricular and supraventricular arrhythmias before and after radiofrequency ablation (RFA) of heart rhythm disturbances.Materials and methods. The study included 49 adolescents aged 11–17 years, of which 15 had Wolff – Parkinson – White pattern (WPW), 13 – WPW syndrome, 10 – atrioventricular nodal reentry tachycardia (AVNRT), and 11 – ventricular arrhythmia (VA). The control group consisted of 11 adolescents without cardiovascular pathology. All patients received surgical treatment for heart rhythm disturbances (HRD) using RFA. In patients with HRD, β-ARM was determined by a set of reagents BETA-ARM AGAT (AGAT LLC, Russia) before RFA and 3 days after it. In the control group, the parameter was determined at the stage of inclusion in the study.Results. In adolescents with supraventricular arrhythmias, median values of β-ARM did not differ significantly from the control group. RFA in adolescents in these groups did not affect the value of β-ARM on day 3 after the surgery. In adolescents with VA, the median value of β-ARM was initially higher than in the control group (p = 0.026). On day 3 after RFA, an increase in β-ARM was noted in this group (p = 0.028) compared to baseline values.Conclusion. Activation of the sympathetic nervous system plays a significant role in the pathogenesis of VA in adolescence. The study showed the possibility of using β-ARM to assess the state of the sympathetic nervous system in patients with methodological limitations in analyzing heart rate variability.

B-257 Dont go breaking my heart: use and misuse of beta-blockers in clinical and forensic casework (2019-2023)

Abstract Background Beta-adrenergic antagonists, or beta-blockers, are commonly prescribed for the treatment and prevention of a variety of cardiovascular issues and other health conditions. These include, but are not limited to heart failure, heart rhythm disturbances, high blood pressure, hypertension, anxiety, asthma, glaucoma, and migraines. Beta-blockers work by blocking access to beta-receptors, which then enhance or inhibit cellular activity and result in dilating blood vessels and relaxing the heart muscle. When misused, accidentally or intentionally, serious adverse effects including dizziness, seizure, heart failure, QTc prolongation, coma, and death can occur. In routine toxicology testing, beta-blockers are often reported qualitatively, which likely underestimates the reporting of related adverse events. We performed a retrospective review to evaluate quantitative levels of beta-blockers in blood and identify trends of potential misuse. Methods We queried our laboratory’s data management system from 2019-2023 for reported findings of beta-blockers in blood. Analytes were quantified with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Results were analyzed using Microsoft Office software. Results Blood results and a comparison of known therapeutic and adverse concentrations are shown in Table 1. Age and sex were reported in 50% and 74% of cases, respectively. Average age ranged from 43 years old (propranolol) to 59 years old (atenolol and metoprolol), without major differences between sexes. Overall use of beta-blockers was split evenly between men and women. Importantly, each analyte provided examples which far exceeded known therapeutic levels, with several cases submitted as potential overdoses. Conclusions Since beta-blockers are generally reported qualitatively during routine toxicology testing, concentrations are unknown. Quantitative testing has shown that beta-blocker concentrations often exceed known therapeutic ranges, which can lead to adverse effects and fatal outcomes. Physicians and death investigators should be aware of these adverse effects and the need for specialized testing in the event of suspected beta-blocker toxicity.

BMAL1 Deficiency Provokes Dry Mouth and Eyes by Down-regulating ITPR2/3

Secretory glands, responsible for tears and saliva production, play essential roles in maintaining ocular and oral well-being. Disruptions in gland secretion can arise from various factors, including rhythm disturbances associated with sleep disorders. However, the underlying mechanisms governing these disruptions remain largely unexplored. We demonstrate that BMAL1, a core component of the circadian system, plays a critical role in regulating secretory gland secretion. Loss of BMAL1 induces vacuolation and atrophy phenotypes in acinar cells, subsequently leading to cell apoptosis and gland hypofunction, but does not cause Sjogren's syndrome, which is characterized by localized inflammatory cell infiltration. Mechanically, BMAL1 directly modulates the transcription of ITPR2 and ITPR3, thereby altering the secretion of Lactoferrin and Lysozyme. Restoration of ITPR2 and ITPR3 expression in Bmal1-deficient rats effectively alleviated the symptoms of lacrimal and parotid glands secretory dysfunction and significantly reduced dry mouth and dry eye conditions in rhythm-disordered rats. These findings highlight the essential role of BMAL1 in regulating salivary and lacrimal gland secretion and suggest a novel therapeutic approach for treating dry mouth and dry eyes associated with rhythm disorders.

A study on serum potassium and serum magnesium levels in acute myocardial infarction with special emphasis on rhythm disturbance

Background and objectives. Myocardial infarction (MI) is a severe cardiac event associated with plaque formation in arteries, leading to reduced blood flow to the heart. Arrhythmias, such as bradyarrhythmia or tachyarrhythmia, commonly accompany MI, contributing to its morbidity and mortality. Electrolyte disturbances, particularly potassium and magnesium imbalances, can exacerbate arrhythmic risks in MI patients. This study aimed to assess the incidence of alterations in serum potassium and magnesium levels during acute MI and their correlation with rhythm disturbances. Material and methods. A prospective analytical study was conducted with 150 patients diagnosed with acute MI based on ECG changes and elevated cardiac markers. Serum potassium and magnesium levels were measured, and rhythm disturbances were assessed using continuous cardiac monitoring and standard ECG. Spearman correlation analysis was performed to evaluate the association between serum potassium, serum magnesium, and rhythm changes. Results. The study investigated the demographic and clinical characteristics of participants and the potential relationship between serum electrolyte levels and arrhythmic changes. The mean age of the participants was 54.3 years, with a male predominance (76% male, 24% female). Among the participants, 50.67% had diabetes, 52% had hypertension, and 28% had both conditions. Serum electrolyte analysis showed elevated magnesium levels in 6.66% and elevated potassium levels in 12.66% of patients. Notably, arrhythmic changes in ECG were present in 62% of patients, with sinus tachycardia being the most prevalent (17%). However, statistical analysis revealed no significant correlation between serum magnesium, serum potassium, and rhythm changes (p >0.05). These findings suggest that while arrhythmic changes are common, they are not directly associated with elevated levels of these electrolytes, indicating the need for further investigation into other potential factors influencing arrhythmias in this population. Conclusion. Despite the prevalence of electrolyte disturbances in acute MI patients, this study found no significant association between serum magnesium, serum potassium levels, and rhythm disturbances. Further research is warranted to elucidate the complex interplay between electrolyte imbalances and arrhythmias in MI.