Search Results (13)

In metabolic syndrome, cardiomyocyte changes induced by metabolic and proinflammatory factors impair repolarization and exacerbate the heterogeneity of the transmural dispersion of repolarization, and this is proarrhythmogenic. Limited data in the literature on the capabilities of speckle tracking echocardiography for assessing proarrhythmogenicity in metabolic syndrome exists. 71 patients with newly diagnosed metabolic syndrome, aged 35–55 years, were studied. Ischemic heart disease was excluded in all patients with stress test cycle ergometry, CT-angiography or selective coronary angiography. All patients underwent a 48-h Holter ECG recording. Based on the latter, they were divided into two groups: 38 patients (53.5%) with a high arrhythmogenic load (supraventricular or ventricular tachycardia, atrial fibrillation/flutter, ventricular extrasystoles over 10%, frequent supraventricular extrasystoles > 500/24 h are included); and 33 patients (46.5%) with low arrhythmogenic load (no significant rhythm disturbances are included). Echocardiography was performed with a GE Vivid T9 emphasizing global longitudinal strain, mechanical dispersion index and left atrium strains. Statistically significant differences in the global longitudinal strain, mechanical dispersion index, and left atrium strain were found between the group with low arrhythmogenicity and the group with high arrhythmogenicity (p < 0.0001). The index of mechanical dispersion has the most optimal sensitivity and specificity of all investigated echocardiographic markers. These results support the mechanical dispersion index as an additional tool for assessing proarrhythmogenicity in metabolic syndrome. Full article

Background and Objectives: The perioperative use of beta-blockers remains controversial due to conflicting evidence of their risks and benefits. The aim of this study was to evaluate the association between chronic beta-blocker (bb) therapy and perioperative cardiac events in non-cardiac surgeries using 24 h continuous Holter monitoring. Materials and Methods: A prospective observational study was conducted on patients undergoing elective or emergency non-cardiac surgery at a Romanian tertiary care hospital. The patients were divided into two groups: G1 (not receiving Bb) and G2 (on chronic Bb). The incidences of perioperative cardiac events, such as severe bradycardia (<40 b/min), new-onset atrial fibrillation (AF), extrasystolic arrhythmia (Ex), and sustained ventricular tachycardia (sVT) and arterial hypotension, were compared between the two groups using clinical, electrocardiography (ECG), and Holter ECG data. Beta-blocker indications, complications, and outcomes were analyzed using chi-squared tests and logistic regression. Results: A total of 100 consecutive patients (63% men, mean age of 53.7 years) were enrolled in the study. G2 included 30% (n = 30) of patients on chronic beta-blocker therapy. The indications included atrial fibrillation (46.7%, n = 14), arterial hypertension (36.7%, n = 11), extrasystolic arrhythmias (10%, n = 3), and chronic coronary syndrome (6.6%, n = 2). Beta-blocker use was significantly associated with severe bradycardia (n = 6; p < 0.001) in G2, whereas one patient in G1 had bradycardia, and 15 and 1 patients had hypotension (p < 0.001) in G1 and G2, respectively. The bradycardia and arterial hypotension cases were promptly treated and did not influence the patients’ prognoses. The 14 patients with AF in G2 had a 15-fold higher odds of requiring beta-blockers (p < 0.001, odds ratio (OR) = 15.145). No significant associations were found between beta-blocker use and the surgery duration (p = 0.155) or sustained ventricular tachycardia (p = 0.857). Ten patients developed paroxysmal postoperative atrial fibrillation (AF), which was related to longer surgery durations (165 (150–180) vs. 120 (90–150) minutes; p = 0.002) and postoperative anemia [hemoglobin (Hg): 10.4 (9.37–12.6) vs. 12.1 (11–13.2) g/dL; p = 0.041]. Conclusions: Patients under chronic beta-blocker therapy undergoing non-cardiac surgery have a higher risk of perioperative bradycardia and hypotension. Continuous Holter monitoring proved effective in detecting transient arrhythmic events, emphasizing the need for careful perioperative surveillance of these patients, especially the elderly, in order to prevent cardiovascular complications These findings emphasize the necessity of tailored perioperative beta-blocker strategies and support further large-scale investigations to optimize risk stratification and management protocols. Full article

Background/Objectives: Immune checkpoint inhibitor (ICI)-associated cardiovascular adverse events are relatively uncommon; they can be life-threatening, particularly when involving malignant ventricular arrhythmias. Electrocardiographic markers such as P-wave dispersion (PWD), QT dispersion (QTd), T-peak to T-end (Tp-e) interval, and Tp-e/QT and Tp-e/QTc ratios have been linked to an elevated risk of both atrial and ventricular arrhythmias and sudden cardiac death across various cardiac conditions. Monitoring these parameters may aid in identifying the risk of arrhythmogenic events in cancer patients undergoing ICI therapy. Methods: This retrospective cohort study analyzed 42 patients with cancer who received ICI therapy and had serial 12-lead electrocardiograms (ECGs) performed at baseline and at three-month intervals during the first year of treatment, from May 2022 to November 2023. ECG parameters including PWD, QTd, Tp-e interval, and Tp-e/QT and Tp-e/QTc ratios were measured and compared between baseline and follow-up time points. Results: The median follow-up duration was 5.3 months (range: 0.5–18.9 months). No statistically significant differences were observed in any of the ECG parameters between baseline and subsequent measurements (p > 0.05). One patient developed atrial fibrillation during the third month of treatment. Additionally, one patient exhibited a left anterior fascicular block, and another experienced frequent ventricular extrasystoles. No malignant ventricular arrhythmias were reported throughout the study period. Conclusions: This study found no significant changes in electrocardiographic markers associated with arrhythmia risk during ICI treatment. Larger, multicenter, prospective studies with extended follow-up are warranted to further elucidate the cardiovascular safety profile of ICIs. Full article

Introduction: Atrial fibrillation (AF), apart from non-stenotic supracardiac atherosclerosis and neoplastic disease, is the leading cause of cryptogenic stroke, including embolic stroke of un-determined source (ESUS). The aim of our study was to determine the prevalence of AF in ESUS patients based on 30-day telemetric heart rate monitoring initiated within three months after stroke onset. Another aim was to identify factors that increase the likelihood of detecting subsequent AF among ESUS patients. Material and Methods: patients with first-ever stroke classified as per the ESUS definition were eligible for this study. All patients underwent outpatient 30-day telemetric heart rate monitoring. Results: In the period between 2020 and 2022, 145 patients were included. The mean age of all qualified patients was 54; 40% of eligible patients were female. Six patients (4.14%), mostly male patients (4 vs. 2), were diagnosed with AF within the study period. In each case, the diagnosis related to a patient whose stroke occurred in the course of large vessel occlusion. Episodes of AF were detected between day 1 and 25 after starting ECG monitoring. Out of the analyzed parameters that increase the probability of, A.F.; only supraventricular extrasystoles proved to be an independent factor regarding an increased risk of AF [OR 1.046, CI 95% 1.016–1.071, p-value < 0.01]. Conclusions: The use of telemetry heart rhythm monitoring in an outpatient setting can detect AF in 4% of ESUS patients who have undergone prior diagnostic procedures for cardiogenic embolism. Supraventricular extrasystoles significantly increases the likelihood of AF detection in patients with ESUS within three months following stroke. Comorbid coronary artery disease, diabetes and hypertension, rather than a single-factor clinical burden, increase the likelihood of AF detection in older ESUS patients. ESUS in the course of large vessel occlusion is probably associated with an increased likelihood of cardiogenic embolism. Full article

Ambulatory 24–72 h Holter ECG monitoring is recommended for patients with suspected arrhythmias, which are often transitory and might remain unseen in resting standard 12-lead ECG. Holter manufacturers provide software diagnostic tools to assist clinicians in evaluating these large amounts of data. Nevertheless, the identification of short arrhythmia events and differentiation of the arrhythmia type might be a problem in limited Holter ECG leads. This observational clinical study aims to explore a novel and weakly investigated ECG modality integrated into a commercial diagnostic tool ECHOView (medilog DARWIN 2, Schiller AG, Switzerland), while used for the interpretation of long-term Holter-ECG records by a cardiologist. The ECHOView transformation maps the beat waveform amplitude to a color-coded bar. One ECHOView page integrates stacked color bars of about 1740 sequential beats aligned by R-peak in a window (R ± 750 ms). The collected 3-lead Holter ECG recordings from 86 patients had a valid duration of 21 h 20 min (19 h 30 min–22 h 45 min), median (quartile range). The ECG rhythm was reviewed with 3491 (3192–3723) standard-grid ECG pages and a substantially few number of 51 (44–59) ECHOView pages that validated the ECHOView compression ratio of 67 (59–74) times. Comments on the ECG rhythm and ECHOView characteristic patterns are provided for 14 examples representative of the most common rhythm disorders seen in our population, including supraventricular arrhythmias (supraventricular extrasystoles, paroxysmal supraventricular arrhythmia, sinus tachycardia, supraventricular tachycardia, atrial fibrillation, and flutter) and ventricular arrhythmias (ventricular extrasystoles, non-sustained ventricular tachycardia). In summary, the ECHOView color map transforms the ECG modality into a novel diagnostic image of the patient’s rhythm that is comprehensively interpreted by a cardiologist. ECHOView has the potential to facilitate the manual overview of Holter ECG recordings, to visually identify short-term arrhythmia episodes, and to refine the diagnosis, especially in high-rate arrhythmias. Full article

Heartbeat rhythms are related to a complex dynamical system based on electrical activity of the cardiac cells usually measured by the electrocardiogram (ECG). This paper presents a mathematical model to describe the electrical activity of the heart that consists of three nonlinear oscillators coupled by delayed Duffing-type connections. Coupling alterations and external stimuli are responsible for different cardiac rhythms. The proposed model is employed to build synthetic ECGs representing a variety of responses including normal and pathological rhythms: ventricular flutter, torsade de pointes, atrial flutter, atrial fibrillation, ventricular fibrillation, polymorphic ventricular tachycardia and supraventricular extrasystole. Moreover, the sinoatrial rhythm variations are described by time-dependent frequency, representing transient disturbances. This kind of situation can represent transitions between different pathological behaviors or between normal and pathological physiologies. In this regard, a nonlinear dynamics perspective is employed to describe cardiac rhythms, being able to represent either normal or pathological behaviors. Full article

OBJECTIVE: To assess the safety of electrotherapy applied in the knee area in patients with known atrial arrhythmias or ischemic heart disease, as it is not known whether this treatment induces or aggravates arrhythmias during or immediately after therapy. MATERIAL AND METHODS: The analytical and transversal study involved 46 patients with degenerative knee osteoarthritis (OA), with or without cardiac diseases, from the Clinical Rehabilitation Hospital inpatient center, Cluj-Napoca, Romania. All patients underwent a 10-day physical therapy program for knee OA (electrotherapy, massage and kinesiotherapy). Heart rate and the total number of ventricular and supraventricular extrasystoles were evaluated before and after treatment, by 24 h Holter ECG monitoring. RESULTS: There was no significant increase in heart rate or in the number of ventricular or supraventricular extrasystoles before or after electrotherapy treatment, regardless of the positive or negative history of arrhythmia or ischemic heart disease (all p > 0.05). Mean values during day 1 were: 35.15 (95% CI [9.60–60.75]) for ventricular ones extrasystoles and 91.7 (95% CI [51.69–131.7]) for supraventricular ones, which during day 2 were 38.09 (95% CI [3.68–72.50]), 110.48 (95% CI [48.59–172.36]), respectively. CONCLUSION: One of the most important things to consider when dealing with an OA patient is that they are most likely older than 65 years, which increases the chance of having a cardiac disease. This raises the need for viable interventions regarding the management of this disease in patients that probably have multiple comorbidities, and where pharmacological and surgical management are not possible, limited or have multiple side effects. Electrotherapy used for treating knee OA did not cause a significant increase in heart rate or number of ventricular and supraventricular extrasystoles in this category of patients. Full article

Background: In patients with complete atrioventricular block (AVB), the prevalence and clinical characteristics of patients with pause-dependent AVB (PD-AVB) is not known. Our objective was to assess the prevalence of PD-AVB in a population of patients with complete (or high-grade) AVB. Methods: Twelve-lead electrocardiogram (ECG) and/or telemonitoring from patients admitted (from September 2020 to November 2021) for complete (or high-degree) AVB were prospectively collected at the University Hospital of Nice. The ECG tracings were analyzed by an electrophysiologist to determine the underlying mechanism of PD-AVB. Results: 100 patients were admitted for complete (or high-grade) AVB (men 55%; 82 ± 12 years). Arterial hypertension was present in 68% of the patients. Baseline QRS width was 117 ± 32 ms, and mean left ventricular ejection fraction was 56 ± 7%. Fourteen patients (14%) with PD-AVB were identified, and presented similar clinical characteristics in comparison with patients without PD-AVB, except for syncope (which was present in 86% versus 51% in the non-PD-AVB patients, p = 0.01). PD-AVB sequence was induced by: Premature atrial contraction (8/14), premature ventricular contraction (5/14), His extrasystole (1/14), conduction block in a branch (1/14), and atrial tachycardia termination (1/14). All patients with PD-AVB received a dual-chamber pacemaker during hospitalization. Conclusion: The prevalence of PD-AVB was 14%, and may be underestimated. PD-AVB episodes were more likely associated with syncope in comparison with patients without PD-AVB. Full article

Computer modeling of the electrophysiology of the heart has undergone significant progress. A healthy heart can be modeled starting from the ion channels via the spread of a depolarization wave on a realistic geometry of the human heart up to the potentials on the body surface and the ECG. Research is advancing regarding modeling diseases of the heart. This article reviews progress in calculating and analyzing the corresponding electrocardiogram (ECG) from simulated depolarization and repolarization waves. First, we describe modeling of the P-wave, the QRS complex and the T-wave of a healthy heart. Then, both the modeling and the corresponding ECGs of several important diseases and arrhythmias are delineated: ischemia and infarction, ectopic beats and extrasystoles, ventricular tachycardia, bundle branch blocks, atrial tachycardia, flutter and fibrillation, genetic diseases and channelopathies, imbalance of electrolytes and drug-induced changes. Finally, we outline the potential impact of computer modeling on ECG interpretation. Computer modeling can contribute to a better comprehension of the relation between features in the ECG and the underlying cardiac condition and disease. It can pave the way for a quantitative analysis of the ECG and can support the cardiologist in identifying events or non-invasively localizing diseased areas. Finally, it can deliver very large databases of reliably labeled ECGs as training data for machine learning. Full article

Heart rate variability, which is the fluctuation of the R-R interval (RRI) in electrocardiograms (ECG), has been widely adopted for autonomous evaluation. Since the HRV features that are extracted from RRI data easily fluctuate when arrhythmia occurs, RRI data with arrhythmia need to be modified appropriately before HRV analysis. In this study, we consider two types of extrasystoles—premature ventricular contraction (PVC) and premature atrial contraction (PAC)—which are types of extrasystoles that occur every day, even in healthy persons who have no cardiovascular diseases. A unified framework for ectopic RRI detection and a modification algorithm that utilizes an autoencoder (AE) type of neural network is proposed. The proposed framework consists of extrasystole occurrence detection from the RRI data and modification, whose targets are PVC and PAC. The RRI data are monitored by means of the AE in real time in the detection phase, and a denoising autoencoder (DAE) modifies the ectopic RRI caused by the detected extrasystole. These are referred to as AE-based extrasystole detection (AED) and DAE-based extrasystole modification (DAEM), respectively. The proposed framework was applied to real RRI data with PVC and PAC. The result showed that AED achieved a sensitivity of 93% and a false positive rate of 0.08 times per hour. The root mean squared error of the modified RRI decreased to 31% in PVC and 73% in PAC from the original RRI data by DAEM. In addition, the proposed framework was validated through application to a clinical epileptic seizure problem, which showed that it correctly suppressed the false positives caused by PVC. Thus, the proposed framework can contribute to realizing accurate HRV-based health monitoring and medical sensing systems. Full article

It is known that in pathological conditions, physiological systems develop changes in the multiscale properties of physiological signals. However, in real life, little is known about how changes in the function of one of the two coupled physiological systems induce changes in function of the other one, especially on their multiscale behavior. Hence, in this work we aimed to examine the complexity of cardio-respiratory coupled systems control using multiscale entropy (MSE) analysis of cardiac intervals MSE (RR), respiratory time series MSE (Resp), and synchrony of these rhythms by cross multiscale entropy (CMSE) analysis, in the heart failure (HF) patients and healthy subjects. We analyzed 20 min of synchronously recorded RR intervals and respiratory signal during relaxation in the supine position in 42 heart failure patients and 14 control healthy subjects. Heart failure group was divided into three subgroups, according to the RR interval time series characteristics (atrial fibrillation (HFAF), sinus rhythm (HFSin), and sinus rhythm with ventricular extrasystoles (HFVES)). Compared with healthy control subjects, alterations in respiratory signal properties were observed in patients from the HFSin and HFVES groups. Further, mean MSE curves of RR intervals and respiratory signal were not statistically different only in the HFSin group (p = 0.43). The level of synchrony between these time series was significantly higher in HFSin and HFVES patients than in control subjects and HFAF patients (p < 0.01). In conclusion, depending on the specific pathologies, primary alterations in the regularity of cardiac rhythm resulted in changes in the regularity of the respiratory rhythm, as well as in the level of their asynchrony. Full article

The predisposition of atrial extrasystoles (AES) to trigger cardiac tachyarrhythmia may arise from intramural conduction disorders causing endo-epicardial asynchrony (EEA). This study aimed to determine whether spontaneous AES disturb endo-epicardial conduction. Simultaneous endo-epicardial mapping of the right atrium was performed in patients during cardiac surgery with two 128-electrode arrays. Sixty spontaneous AES were observed in 23 patients and were analyzed for incidence of conduction delay, conduction block and amount of EEA compared to the previous sinus rhythm beat. Both conduction delay and block occurred more often in AES compared to sinus rhythm. The difference in lines of conduction block between the epicardium and endocardium increased in AES causing a greater imbalance of conduction disorders between the layers. The incidence of EEA with differences ≥10 ms increased significantly in AES. AES caused delays between the epicardium and endocardium up to 130 ms and EEA to increase for up to half (47%) of the mapping area. Conduction disturbances between the epicardial and endocardial layer giving rise to EEA increase during AES. Asynchronous activation of the atrial layers increases during AES which may be a mechanism for triggering cardiac tachyarrhythmia under the right conditions but EEA cannot be recognized by current mapping tools. Full article

A 36-year-old woman was seen at the Cardiac Congenital Clinic for her annual visit. She was born with a dtransposition of the great arteries (d-TGA) and underwent a Rashkind procedure shortly after birth, followed by a Senning procedure (atrial switch) in 1978. She recently went through two uncomplicated pregnancies and is asymptomatic except for occasional palpitations documented as ventricular extrasystoles and bigeminy. She does not take medication [...] Full article