Arrhythmic Patterns Research Articles

ND15, subunit of the electron transport chain protein-complex I, age-dependently worsens cardiac performance in Drosophila melanogaster

Abstract Introduction In the natural aging process of the heart, aside others, mitochondrial dysfunction is an essential driver for the development of reduced cardiac performance. Previous analysis of protein expression levels in cardiomyocytes of aged mice and have found aberrancies in subunits of the mitochondrial Complexes I – IV of the electron transport chain. Especially, the complex I subunit ND15 was highly downregulated. To elucidate the functional effects of this gene on the cardiac performance, we generated cardiomyocyte specific ND15 knock-downs in Drosophila melanogaster. Methods We generated Drosophila with heart-specific (+/+; Hand4.2-GAL4/UAS-ND15; tdtK/+) (ND15-KD)knockdown of ND15 using the UAS/GAL4 system. The flies' cardiomyocytes endogenously express tdTomato, facilitating fluorescence-based live imaging of the heart by high-resolution video fluorescence microscopy. The recorded data was processed using a R-Script, resulting in Results We compared wild type (WT) flies to ND15-KD flies at age 3 weeks(young) and 7 weeks(old). Knockdown of ND15 resulted in impaired cardiac function. Most parameters deteriorated in aged flies in comparison to young flies. The heart frequency was significantly reduced (WT:6 beats/s – KD:4 beats/s – p<0.0001) in the 7 weeks old group, end-diastolic diameter of the heart tube increased significantly in 3 weeks old ND15KD flies compared to controls(WT:65µm – KD:74µm p<0,0001), resulting in a dilated heart tube Interestingly enough, this dilation in ND15-KD disappeared in 7 weeks old flies. The fractional shortening was significantly decreased in young(WT:33,5% - KD:30% p<0,01) and deteriorated in old flies (WT:35% - KD:22% p<0,0001), indicating a reduced contraction capability. For both 3 weeks and 7 weeks old groups, the heart-rate adjusted interbeat interval variance (WT:22% -KD: 40% p<0,0001) as well as the time of no cardiac action (WT: 22% - KD: 35% p<0,0001) increased and showed significant irregularities. The duration of systole and diastole combined also exhibited arrhythmic patterns (WT:15% - KD:20.5% p<0,0001). A general arrhythmia index (AI) increased significantly (WT: 0.25 – KD:0.5 p<0,0001) These arrhythmia parameters emphasize the arrhythmogenic potential of the ND15-knockdown. The relative relaxation capabilities drastically worsened with age, displaying a diastolic dysfunction in the 7 weeks old group. At half-time relaxation, the WT was at 60% relaxation, ND15KD at 46%). Conclusion This study demonstrates that heart-specific deletion of ND15 results in a marked impairment of systolic and diastolic cardiac function in Drosophila accompanied by pro-arrhythmogenic actions. We could identify ND15 as a new mitochondrial molecular target for the maintenance of regular cardiac function and rhythmicity, especially with increasing age. Further mechanistic studies and translation to mammalian organisms are ongoing.

Characterization of Post Coronary Artery Bypass Grafting Atrial Fibrillation Patterns: Rationale and Design of an Investigator-Initiated Observational Study

New-onset postoperative atrial fibrillation (POAF) after cardiac surgery is associated with increased rates of adverse events (including mortality and stroke). Its incidence after coronary artery bypass grafting (CABG) is considered to be approximately 30 % and it is thought to be a transient condition. However, studies investigating POAF after CABG fail to provide appropriate data on incidence and arrhythmia patterns due to the use of intermittent rhythm detection strategies. These methods have a low sensitivity as compared to continuous monitoring. Subsequently, studies utilizing these techniques most likely do not identify all patients with arrhythmia and do not adequately demonstrate the long-term incidence of arrhythmia, which in turn may affect its association with adverse events. The CABG-AF study (German Clinical Trials Register Nr.: DRKS00018887) tests the hypothesis that the incidence of AF in the first 12 months after CABG is significantly underestimated. CABG-AF is an investigator-initiated multicenter, prospective, observational study in which 196 patients with no history of arrhythmia undergoing first-time CABG, receive an insertable cardiac monitor for continuous postoperative rhythm monitoring. The primary endpoint of the study is any episode of AF within the first 12 months after surgery. Secondary endpoints include AF burden, AF density and the ratio of silent to symptomatic AF episodes. Endpoints will be investigated by automatic and patient-initiated data transfers from the implanted device, by telephone interview of patients and by follow-up forms sent to patients by mail. The patients will be followed for a planned follow-up of 3 years. In conclusion, the CABG-AF study will provide information on the true incidence of AF after CABG as well as on the temporal patterns of the arrhythmia.

Rhythmic Temporal Cues Coordinate Cross-frequency Phase-amplitude Coupling during Memory Encoding.

Accumulating evidence suggests that rhythmic temporal cues in the environment influence the encoding of information into long-term memory. Here, we test the hypothesis that these mnemonic effects of rhythm reflect the coupling of high-frequency (gamma) oscillations to entrained lower-frequency oscillations synchronized to the beat of the rhythm. In Study 1, we first test this hypothesis in the context of global effects of rhythm on memory, when memory is superior for visual stimuli presented in rhythmic compared with arrhythmic patterns at encoding [Jones, A., & Ward, E. V. Rhythmic temporal structure at encoding enhances recognition memory, Journal of Cognitive Neuroscience, 31, 1549-1562, 2019]. We found that rhythmic presentation of visual stimuli during encoding was associated with greater phase-amplitude coupling (PAC) between entrained low-frequency (delta) oscillations and higher-frequency (gamma) oscillations. In Study 2, we next investigated cross-frequency PAC in the context of local effects of rhythm on memory encoding, when memory is superior for visual stimuli presented in-synchrony compared with out-of-synchrony with a background auditory beat (Hickey et al., 2020). We found that the mnemonic effect of rhythm in this context was again associated with increased cross-frequency PAC between entrained low-frequency (delta) oscillations and higher-frequency (gamma) oscillations. Furthermore, the magnitude of gamma power modulations positively scaled with the subsequent memory benefit for in- versus out-of-synchrony stimuli. Together, these results suggest that the influence of rhythm on memory encoding may reflect the temporal coordination of higher-frequency gamma activity by entrained low-frequency oscillations.

Tachyarrhythmias in congenital heart disease.

The prevalence of congenital heart disease (CHD) in adult patients has risen with advances in diagnostic and surgical techniques. Surgical modifications and hemodynamic changes increase the susceptibility to arrhythmias, impacting morbidity and mortality rates, with arrhythmias being the leading cause of hospitalizations and sudden deaths. Patients with CHD commonly experience both supraventricular and ventricular arrhythmias, with each CHD type associated with different arrhythmia patterns. Macroreentrant atrial tachycardias, particularly cavotricuspid isthmus-dependent flutter, are frequently reported. Ventricular arrhythmias, including monomorphic ventricular tachycardia, are prevalent, especially in patients with surgical scars. Pharmacological therapy involves antiarrhythmic and anticoagulant drugs, though data are limited with potential adverse effects. Catheter ablation is preferred, demanding meticulous procedural planning due to anatomical complexity and vascular access challenges. Combining imaging techniques with electroanatomic navigation enhances outcomes. However, risk stratification for sudden death remains challenging due to anatomical variability. This article practically reviews the most common tachyarrhythmias, treatment options, and clinical management strategies for these patients.

Type of atrial arrhythmias and substrates after convergent ablation procedures

Abstract Background Convergent epicardial and endocardial catheter ablation had been used for the treatment of persistent atrial fibrillation (PeAF). Aims The aims of this retrospective study are to describe the pattern of arrhythmias and substrate findings in patients previously submitted to convergent ablation and showing arrhythmic recurrences (AF/AT/AFL lasting at least 30 seconds) and documented with ILR during follow up. Methods From a cohort of 119 patient who underwent convergent ablation, we selected the 55 with arrhythmic recurrences and showing AT/AF/AFL stored in ILR memories to submit them to remap procedure. Results We excluded 1 patient who was submitted to ablate and pace without remapping and 1 patient whose data has been lost. Among 53 patients, 69.7% experienced AF (33.9% PAF and 35.8% PeAF), 5.6% typical AFL and 30.2% AT/atypical AFL. As for the substrates found, at detailed high-density mapping we had: 66.9% with veins reconnection (regardless the gaps localization), 37.7% with low-voltage area/abnormal signals on the posterior wall, 11.3% deserving CTI ablation for typical AFL and 28.3% with different LA substrates (septal, anterior, LAA, mitral annulus and 9.4% with gaps at superior surgical line). Notably, overlaps of arrhythmic patterns and substrate were also found in the same patients. Conclusion In our study a total of 79.1% patients had substrates related to previous convergent ablation due to gaps at pulmonary veins or superior line. The rest had an arrhythmic substrate in areas not previously ablated like posterior wall or CTI. These findings suggest that a large amount of patients submitted to convergent ablation (up to 80%) may have an arrhythmic substrate and thus potentially recurrences due to previous epi-endocardial ablation.

Modeling the Electrical Activity of the Heart via Transfer Functions and Genetic Algorithms.

Although healthcare and medical technology have advanced significantly over the past few decades, heart disease continues to be a major cause of mortality globally. Electrocardiography (ECG) is one of the most widely used tools for the detection of heart diseases. This study presents a mathematical model based on transfer functions that allows for the exploration and optimization of heart dynamics in Laplace space using a genetic algorithm (GA). The transfer function parameters were fine-tuned using the GA, with clinical ECG records serving as reference signals. The proposed model, which is based on polynomials and delays, approximates a real ECG with a root-mean-square error of 4.7% and an R2 value of 0.72. The model achieves the periodic nature of an ECG signal by using a single periodic impulse input. Its simplicity makes it possible to adjust waveform parameters with a predetermined understanding of their effects, which can be used to generate both arrhythmic patterns and healthy signals. This is a notable advantage over other models that are burdened by a large number of differential equations and many parameters.

Patterns of perioperative arrhythmias in adult cardiac surgery: A single center study from Sri Lanka

Introduction: There is no published data on perioperative arrhythmias in adults undergoing cardiac surgery in Sri Lanka. The object of this study was to assess the patterns of peri operative arrhythmias in cardiac surgical patients. Methods and material: This is a prospective descriptive study of 100 patients in a single cardiothoracic unit in a tertiary care hospital in Sri Lanka from November 2018 to May 2020. Demographic data and clinical data were assessed in all patients. Furthermore, 24-hour Mobile Cardiac Outpatient Telemetry MCOT was assessed in a subset of patients. Results: There were 72 males and 28 females. The mean age was 60 (range 37-76 years). The majority (76) had undergone isolated coronary artery bypass grafting (CABG). The mortality was 3.5% in routine and 15% in urgent and emergency operations. Arrhythmias where lowest preoperatively (11%). Arterial fibrillation (AF) (6%) and sinus bradycardia (4%) were the commonest arrhythmias seen preoperatively. Arrhythmias were higher during surgery (29%) and ventricular fibrillation (VF) (25%) was the commonest. Arrhythmias were highest post operatively (34%) and (AF) (12%) was the commonest followed by sinus tachycardia (9%). The higher incidence of arrhythmias in the in-hospital postoperative period as compared to the preoperative period was significant (p=0.0001). A limited in-depth study using a mobile cardiac telemetry (MCOT) device showed a higher incidence of AF preoperatively (11%) and postoperatively (16%) but these differences were not significant when compared with that of routine investigations (p=0.18 and p=0.35 respectively). However, the MCOT detected some arrhythmias completely missed by routine ECG recordings, notably supraventricular tachycardia, both preoperatively (22%) and postoperatively (33%). Conclusions: This study has established baseline values of perioperative arrhythmias in the adult cardiac surgical patients in Sri Lanka. The MCOT methodology shows the potential for a more detailed study of arrhythmias and could inform decision-making in arrhythmia prophylaxis.

ARRHYTHMOGENIC RIGHT VENTRICULAR CARDIOMYOPATHY AND CARDIAC SARCOIDOSIS: THE GREY ZONE

Abstract Cardiac sarcoidosis (CS) is a rare multisystem disorder characterized by granulomatous infiltration of the myocardium, whose clinical manifestations can be extremely heterogeneus. We report the case of a 47–year–old man with a previous diagnosis of arrhythmogenic right ventricular cardiomyopathy (ARVD). In history he had a marked arrhythmic pattern with multiple episodes of sustained ventricular arrhythmias, biventricular disfunction (LVEF 37%, RVEF 32%) and extensive biventricular transmural late–gadolinium enhancement (greater than 50%) at cardiac RMN. At EKG epsilon wave mainly seen in precordial leads. In November 2022 he was implanted with bicameral defibrillator and in March 2023 he underwent ablation procedure for ventricular tachycardia with RF with endo–epicardial approach. In May 2023 he arrived at our Centre for acute decompensated heart failure. At restored hemodynamic stability, screening for the possible inclusion in transplant list was started. Right heart catheterization (RHC) showed low cardiac index with no pulmonary hypertension. Chest CT unexpectedly showed the presence of multiple micronodules with perilymphatic distribution with confluent appearance compatible with pulmonary sarcoidosis. In consideration of this result, the transplant program was temporarily postponed and investigations for possible cardiac involvement of an inflammatory nature were started. 18F–FDG PET–CT showed pulmonary, splenic, lymphonodal and especially cardiac uptake in the mid–distal segment of the lateral wall of the left ventricle and in the inferior–apical site suspicious for inflammatory pathology. Unfortunately, both lymphonodal and cardiac biopsies were inconclusive because of insufficient material. Nevertheless, the clinical scenario satisfied the Japanese criteria for possible CS; therefore, treatment with prednisone 1 mg/kg was started and a 18F–FDG PET–CT was planned after 3 months of steroid therapy. CS can disguise as a phenocopy of arrhythmogenic right ventricular cardiomyopathy because of several common characteristics, especially arrhythmic presentation. Due to these similarities, a careful overall evaluation of each patient with ARVD is mandatory as several transplant centers have reported cases of CS in explanted heart with a pretransplant misdiagnosis of ARVD or dilated cardiomiopathy. Performing a chest CT in all ARVD patients as part of transplant screening may be considered.

Active Arrhythmia Pattern: A Novel Predictor of ICD Shocks-A Subanalysis From the PARTITA Study.

In the PARTITA trial (Does Timing of Ventricular Tachycardia Ablation Affect Prognosis in Patients With an Implantable Cardioverter Defibrillator?), antitachycardia pacing (ATP) predicted the occurrence of implantable cardioverter defibrillator (ICD) shocks. Catheter ablation of ventricular tachycardia after the first shock reduced the risk of death or worsening heart failure. A threshold of ATPs that might warrant an ablation procedure before ICD shocks is unknown. Our aim was to identify a threshold of ATPs and clinical features that predict the occurrence of shocks and cardiovascular events. We analyzed data from 517 patients in phase A of the PARTITA study. We used classification and regression tree analysis to develop and test a risk stratification model based on arrhythmia patterns and clinical data to predict ICD shocks. Secondary end points were worsening heart failure and cardiovascular hospitalization. Classification and regression tree classified patients into 6 leaves by increasing shock probability. Patients treated with ≥5 ATPs in 6 months (active arrhythmia pattern) had the highest risk of ICD shocks (93% and 86%, training and testing samples, respectively). Patients without ATPs had the lowest (1% and 2%). Other predictors included left ventricle ejection fraction<35%, age of <60 years, and obesity. Survival analysis revealed a higher risk of worsening heart failure (hazard ratio, 5.45 [95% CI, 1.62-18.4]; P=0.006) and cardiovascular hospitalization (hazard ratio, 7.29 [95% CI, 3.66-14.5]; P<0.001) for patients with an active arrhythmia pattern compared with those without ATPs. Patients with an active arrhythmia pattern (≥5 ATPs in 6 months) are associated with an increased risk of ICD shocks, as well as heart failure hospitalization and cardiovascular hospitalization. These data suggest that additional treatments may be helpful to this high-risk group as a preventive strategy to reduce the incidence of major events. Further prospective randomized trials are needed to confirm the benefits of early ventricular tachycardia ablation in this setting.

Pattern of Arrhythmia among Diabetes Mellitus Patients in South-South, Nigeria: 24-Hour Ambulatory ECG (Holter ECG) Study

Background: Diabetes is known to be an independent risk factor for cardiovascular morbidity and mortality, commonly associated with rhythm disorders like atrial fibrillation (AF) and ventricular arrhythmias (VA), Diabetes Mellitus (DM) patients have silent myocardial infarctions (MI) with conduction abnormalities like ectopics and others. Regular 12 lead ECGs may not capture subtle conduction abnormalities unlike Holter ECGs which takes longer time to record heart rhythms. The study aims to determine the occurrence and pattern of cardiac arrhythmias in Diabetes Mellitus. Methods: A total of 33 diabetic subjects with age ranged from 18 years and above presented to Goodheart Medical Consultants hospital for 24-hour ambulatory ECG (Holter ECG) using Schiller type (MT-101) Holter ECG machine. Results: In this study, the population consisted of 54.5% men and 45.5% women with a mean age of 63.4 ±14.41, the most common age group was 61–80 years with 42.4%. The two most common forms of arrhythmias for Holter ECGs in this study were supraventricular ectopics 36.4% and ventricular ectopics 33.3%. Conclusion: Supraventricular ectopics is the most common arrhythmia observed among the diabetic subjects in Southern Nigeria and was notably observed more in diabetic male subjects than females. This arrhythmia exposes them to risk of stroke and mortality. Diabetes-related arrhythmias may be a sign of other underlying illnesses.

Pattern of Arrhythmia among Ischemic Stroke Patients on 24-hour Ambulatory Electrocardiography (Holter ECG) in South-South Nigeria

Background: The 24-hour Holter electrocardiogram is a valuable tool for the identification of ischaemic alterations, cardiac arrhythmias in hypertension, stroke and other cardiovascular conditions. Electrocardiographic (ECG) abnormalities and cardiac arrhythmias have been detected in 50% of stroke patients. However, literature in this area of research is limited in our environment. This study is aimed at describing the pattern of arrhythmia observed in patients with ischaemic stroke using 24-hour Holter ECG in our locality. Methods: A total of 22 stroke subjects whose age ranged from 41 and 83 years were evaluated in GoodHeart Medical Consultants hospital for 24-hour ambulatory ECG (Holter ECG) from January 2015 – December 2016. The Holter ECG data was acquired using Schiller type (MT-101) Holter ECG machine. Results: The study population consisted of 59.1% females and 40.9% males, with an average age of 66.95±12.32 years. Arrhythmias were more prevalent among females compared to males. However, bradycardia was more prevalent in males. Ventricular ectopics were the most common type of arrhythmia across both genders, with a higher prevalence in the older adult age group of 61-80 years. Conclusion: The most common arrhythmia observed among the stroke subjects in Southern Nigeria is ventricular ectopics. This could be due to increase in age and severe neurological deficit which are independent predictors of arrhythmia onset and this was notably seen among the older subjects in the study. Extended cardiac monitoring such as Holter ECG is a well-accepted method for the identification of ECG abnormalities and the implementation of prompt treatment to reduce mortality.

Low-energy optogenetic technique offers safer arrhythmia treatments

Optical resonant feedback pacing terminated arrhythmia patterns using 50 times less energy than a single-pulse approach.

Pattern of Arrhythmia among Hypertensive Patients in South-South, Nigeria: A 24-H Ambulatory ECG (Holter ECG) Study

Background: Regular 12-lead electrocardiogram (ECG) often fail to detect cardiac conduction abnormalities. Among hypertensive patients, conduction irregularities such as atrial fibrillation and ventricular tachycardia are recognized occurrences and these can be intermittent or asymptomatic. This study aims to evaluate the conduction abnormalities identified among hypertensives by Holter ECG in a private medical facility in South-South, Nigeria. Methods: This is a retrospective study of five hundred and thirteen patients consisting of 255 males and 258 females Holter ECG who presented at a private medical facility from January 2015- December 2016. Holter ECG data was acquired using Schiller type (MT-101) Holter ECG Machine. Results: Out of the 370 hypertensive patients reviewed, with a mean age of 55.18 ±.14.78, 205(55.41%) had tachycardia, 180(48.65%) had bradycardia, 184(49.73%) had ventricular ectopics while 169(45.68%) had supraventricular ectopics. The most common clinical indication was palpitation 150 (40.54%). The most prevalent age group was 41-60 years; 230 (44.83%) as compared to other age groups in the study. Tachycardia was the most common type of arrhythmia among the subjects. There was a higher incidence of arrhythmias in the female subjects than in the male. Conclusion: Tachycardia and ventricular ectopics were the most common conduction abnormalities observed. Beta blockers and anti-arrhythmics would be helpful for optimization of cardiovascular care. Holter ECG is beneficial in describing and characterizing arrhythmias in hypertensive patients in this population therefore, further studies on larger populations and diverse disease conditions are advocated.

Brugada syndrome: identification of subjects at risk and therapy.

Brugada syndrome mainly affects young subjects with structurally normal heart and can cause x syncope or sudden death due to ventricular arrhythmias, even as the first manifestation, in approximately 5-10% of cases. To date, two questions remain open: how to recognize subjects who will experience arrhythmic events and how to treat them. The guidelines suggest treating subjects with a previous history of cardiac arrest or arrhythmogenic syncope, while they are unconclusive about the management of asymptomatic patients, who represent ∼90% of Brugada patients. We recently demonstrated that in asymptomatic patients, the presence of spontaneous Brugada type 1 electrocardiogram (ECG) pattern and inducibility of ventricular arrhythmias at electrophysiological study allows us to identify a group of patients at greater risk who deserve treatment. Regarding treatment, there are three options: implantable cardioverter defibrillator, drugs, and epicardial transcatheter ablation. Recent studies have shown that the latter is effective and free from serious side effects, thus opening a new scenario in the treatment of Brugada patients at risk. Subjects who present drug-induced-only type 1 Brugada ECG pattern, in whom a spontaneous type 1 pattern has been ruled out with repeated ECGs and 12-lead 24-h Holter monitoring, represent a very low-risk group, provided they adhere to behavioural recommendations and undergo regular follow-up.

Novel high-dense microelectrode array based multimodal bioelectronic monitoring system for cardiac arrhythmia re-entry analysis

In recent decades, significant progress has been made in the treatment of heart diseases, particularly in the field of personalized medicine. Despite the development of genetic tests, phenotyping and risk stratification are performed based on clinical findings and invasive in vivo techniques, such as stimulation conduction mapping techniques and programmed ventricular pacing. Consequently, label-free non-invasive in vitro functional analysis systems are urgently needed for more accurate and effective in vitro risk stratification, model-based therapy planning, and clinical safety profile evaluation of drugs. To overcome these limitations, a novel multilayer high-density microelectrode array (HD-MEA), with an optimized configuration of 512 sensing and 4 pacing electrodes on a sensor area of 100 mm2, was developed for the bioelectronic detection of re-entry arrhythmia patterns. Together with a co-developed front-end, we monitored label-free and in parallel cardiac electrophysiology based on field potential monitoring and mechanical contraction using impedance spectroscopy at the same microelectrode. In proof of principle experiments, human induced pluripotent stem cell (hiPS)-derived cardiomyocytes were cultured on HD-MEAs and used to demonstrate the sensitive quantification of contraction strength modulation by cardioactive drugs such as blebbistatin (IC50 = 4.2 μM), omecamtiv and levosimendan. Strikingly, arrhythmia-typical rotor patterns (re-entry) can be induced by optimized electrical stimulation sequences and detected with high spatial resolution. Therefore, we provide a novel cardiac re-entry analysis system as a promising reference point for diagnostic approaches based on in vitro assays using patient-specific hiPS-derived cardiomyocytes.

AI driven ECG arrhythmia diagnosis

The accurate and timely diagnosis of cardiac arrhythmias is crucial for effective patient management and improved health outcomes. However, the precise identification of arrhythmias in electrocardiogram (ECG) data often requires specialized medical expertise, leading to potential delays and errors in diagnosis. To address these challenges, this project introduces an AI-driven system for ECG arrhythmia diagnosis. Employing advanced deep learning techniques, the proposed system leverages a comprehensive dataset of annotated ECG recordings to train a robust model capable of detecting and classifying various types of arrhythmias. The model is designed to process raw ECG signals, extract relevant features, and generate clinically meaningful insights, enabling automated and rapid identification of arrhythmic patterns. Through a user-friendly interface, medical professionals can upload ECG data for real-time analysis, allowing for prompt decision-making and personalized patient care. Furthermore, the system offers interpretable results, highlighting key indicators and providing detailed explanations to aid clinicians in understanding the diagnostic outcomes.

Patterns of respiratory sinus arrhythmia and trajectories of anxiety and depressive symptoms in early adolescence

In children and adults, individual differences in patterns of respiratory sinus arrhythmia (RSA; i.e., interactions between resting RSA and RSA reactivity to stress) have emerged as a central predictor of internalizing symptoms. However, it is unclear whether individual differences in patterns of RSA also contribute to internalizing symptoms during the key developmental period of early adolescence, when rates of internalizing symptoms sharply increase. In the present multi-wave longitudinal study, we assessed whether patterns of RSA predicted trajectories of the two most common types of internalizing symptoms among adolescents: anxiety and depression. In the baseline session, we assessed RSA at rest and in response to a psychosocial stressor (Trier Social Stress Test [TSST]) in a sample of 75 early adolescents (Mage = 12.85). Youth then completed measures of anxiety and depressive symptoms at baseline and four times over approximately two years. Findings indicate that RSA patterns predicted trajectories of anxiety, but not depression. Specifically, region of significance analyses indicated that individuals with high resting RSA who demonstrated RSA augmentation to the lab stressor evinced decreasing anxiety over the follow-up period. In direct contrast, adolescents with high resting RSA in combination with RSA withdrawal to the stressor exhibited a trajectory of increasing anxiety. Findings provide preliminary evidence for understanding RSA as a developmentally salient risk or protective factor.

Clinical profiling and outcomes of viral myocarditis manifesting with ventricular arrhythmias.

Clinical features and risk stratification of patients with viral myocarditis (VM) complicated by ventricular arrhythmias (VA) are incompletely understood. We aim to describe arrhythmia patterns and outcomes in patients with VM and early-onset VA. We present a single-centre study, enrolling patients with VM proven by endomyocardial biopsy, and evidence of VA within 24 h of hospitalization. The incidence of major adverse events (MAE), including all-cause death, severe heart failure, advanced atrioventricular blocks, or major VA, was evaluated during a 24-month follow-up (FU) and compared with a matched group of virus-negative myocarditis. Of patients with VM (n = 74, mean age 47 ± 16 years, 66% males, and left ventricular ejection fraction 51 ± 13%), 20 (27%) presented with major VA [ventricular tachycardia/ventricular fibrillation (VT/VF)], and 32 (44%) had polymorphic VA. Patients with polymorphic VA more commonly had evidence of ongoing systemic infection (24/32 vs. 10/42, P = 0.004) and experienced greater occurrence of MAE at discharge (15/32 vs. 2/42, P < 0.001). However, the incidence of MAE during FU was higher in patients with monomorphic VA compared to those with polymorphic VA (17/42 vs. 2/28, P = 0.002). Patients with monomorphic VA displayed frequently signs of chronic cardiomyopathy and had outcomes comparable with virus-negative myocarditis (log rank P = 0.929). Presentation with VT/VF was independently associated with MAE [at discharge: hazard ratio (HR) 4.7, 95% confidence interval (CI) 1.6-14.0, P = 0.005; during FU: HR 6.3, 95% CI 2.3-17.6, P < 0.001]. In patients with VM, polymorphic VA point to ongoing systemic infection and early adverse outcomes, whereas monomorphic VA suggest chronic cardiomyopathy and greater incidence of MAE during FU. Presentation with VT/VF is independently associated with MAE.

The diagnostic and therapeutic challenge of atrial flutter in children: a case report

BackgroundPalpitations represent a common cause for consultation in the pediatric Emergency Department (ED). Unlike adults, palpitations in children are less frequently dependent from the heart, recognizing other causes.Case presentationA 11-year-old male came to our pediatric ED for epigastric pain, vomiting and palpitations. During the previous 6 month the patient was affected by SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus). Electrocardiogram (ECG) revealed supraventricular tachycardia. Therefore, adenosine was administered unsuccessfully. The administration of adenosine, however, allowed us to make diagnosis of atypical atrial flutter. Multiple attempts at both electrical cardioversion, transesophageal atrial overdrive, and drug monotherapy were unsuccessful in our patient. Consequently, a triple therapy with amiodarone, flecainide, and beta-blocker was gradually designed to control the arrhythmic pattern with the restoration of a left upper atrial rhythm. There was not any evidence of sinus rhythm in the patient clinical history.ConclusionsThe present study underlines the rarity of this type of dysrhythmia in childhood and the difficulties in diagnosis and management, above all in a patient who has never showed sinus rhythm. Raising awareness of all available treatment options is essential for a better management of dysrhythmia in children

Dysrhythmia in acute coronary syndrome patients undergoing coronary artery bypass grafting surgery at hanoi heart hospital

Objectives: Many studies have demonstrated arrhythmias were common in acute coronary syndrome and coronary artery bypass grafting surgery. Although the most of these arrhythmias were transient and have a benign course, but it may represent a significant source of morbidity and mortality. This study aimed to establish the temporal change pattern of arrhythmias observed to determine the incidence and characteristics of dysrhythmia.&#x0D; Methods: A prospective method was used to study 52 consecutive patients with acute coronary syndrome who were assessed using 24-hour Holter recordings before CABG and 1 week, 3 months, and 6 months after the surgery from June 2016 to August 2018 at Hanoi Heart Hospital.&#x0D; Results: New appearance of atrial fibrillation after coronary artery bypass grafting surgery increased by time, at 7 days was 17.3%, after 3 and 6 months were 10 - 18.4%. Percentage of ventricular dysrhythmias was highest before surgery 8.67%, decreased after surgery and lowest after 6 months. The rate of short ventricular tachycardia at 7 days after surgery was highest (11.8%), followed by the preoperative period (3.8%), decreased and disappeared after 6 months. Ventricular arrhythmias with Lown (grade &gt; 3) preoperative was 44.2%, increased at 7 days postop was 51.9% and decreased postop 3 - 6 month (28 - 20%).&#x0D; Conclusion: New appearances of atrial fibrillation after coronary artery bypass grafting surgery increased by time. Dysrhythmia was acutely affected by myocardial ischemia and coronary artery bypass grafting surgery.