Search Results (28)

Type 2 diabetes mellitus is associated with major cardiovascular complications, including cardiac autonomic neuropathy, which contributes to sympathetic–parasympathetic imbalance and increases susceptibility to arrhythmias and sudden cardiac death. Heart rate variability, assessed through R–R intervals on electrocardiography and 24 h Holter monitoring, represents a sensitive, non-invasive marker of autonomic dysfunction and arrhythmogenic risk. In patients with type 2 diabetes mellitus, chronic hyperglycaemia, oxidative stress, and metabolic inflammation lead to early impairment of the autonomic nervous system, manifested by consistent reductions in SDNN, RMSSD, pNN50, total power, and the high-frequency component, indicating diminished parasympathetic tone and sympathetic predominance. Nonlinear HRV indices demonstrate a loss of complexity and fractal organisation, providing additional prognostic value beyond conventional time- and frequency-domain analyses. Reduced HRV correlates with the severity of cardiac autonomic neuropathy, duration of diabetes, and poor glycaemic control, identifying patients with increased arrhythmogenic vulnerability. HRV analysis enables prediction of arrhythmic risk, facilitating the identification of high-risk individuals and guiding personalised interventions. The integration of HRV assessment into routine clinical practice may improve the early detection of subclinical autonomic neuropathy and optimise cardiovascular risk stratification and management in patients with type 2 diabetes mellitus. Full article

Background: Obstructive sleep apnea (OSA) is a major modifiable risk factor for atrial fibrillation (AF), promoting arrhythmogenesis through intermittent hypoxia, autonomic activation, and atrial remodeling. Although continuous positive airway pressure (CPAP) effectively treats OSA, real-world evidence linking objectively measured CPAP exposure to clinically relevant AF recurrence remains limited. Aims: We aimed to evaluate the association between CPAP adherence and risk of recurrent paroxysmal AF, and to compare time to first recurrence between patients with mean nightly CPAP use ≥4 h/night versus <4 h/night. Materials and Methods: In this prospective observational cohort (2017–2024), consecutive hospitalized and outpatient adults with severe obstructive sleep apnea (OSA; apnea–hypopnea index > 30 events/h) and documented paroxysmal atrial fibrillation (AF) were enrolled. Persistent and long-standing persistent AF were excluded to ensure a homogeneous population with respect to atrial substrate. OSA was assessed using home sleep apnea testing (ResMed ApneaLink), and all patients initiated continuous positive airway pressure (CPAP) therapy (ResMed AirSense 10). Objective adherence data were obtained via the ResMed AirView telemonitoring platform. Exclusion criteria included permanent AF, prior pulmonary vein isolation, central sleep apnea, left ventricular ejection fraction < 50%, end-stage chronic kidney disease (eGFR < 15 mL/min/1.73 m² or dialysis), or inability to initiate or maintain CPAP therapy. Patients were followed for 12 months. The primary endpoint was time to first documented recurrence of paroxysmal AF (≥30 s on 12-lead electrocardiography or 24-h Holter monitoring). Progression to permanent AF, defined after unsuccessful rhythm control attempts and subsequent transition to a rate control strategy, was assessed as a secondary endpoint. Time-to-event analyses used Kaplan–Meier estimates with log-rank testing, and Cox proportional hazards regression adjusted for age, body mass index, apnea–hypopnea index, heart failure, left atrial volume index, and antiarrhythmic drug therapy. Results: The final analysis included 91 patients (mean age 62.15 ± 8.29 years; 68.13% men). Mean nightly CPAP use was ≥4 h/night in 49 patients and <4 h/night in 42 patients. During follow-up, paroxysmal AF recurrence occurred in 12/49 (24.5%) patients in the ≥4 h/night group and 16/42 (38.1%) in the <4 h/night group. Mean arrhythmia-free survival at 12 months was numerically higher in the ≥4 h/night group (11.25 vs. 10.51 months), without a statistically significant difference in Kaplan–Meier curves (log-rank p = 0.11). In multivariable Cox regression, binary adherence (≥4 h/night) was not independently associated with recurrence (HR 0.52, p = 0.13), whereas mean nightly CPAP use analyzed as a continuous variable remained independently associated with delayed recurrence (per 1-h increase: HR 0.66, 95% CI 0.48–0.91, p = 0.01). Progression to permanent AF occurred in 4/49 (10.0%) versus 9/42 (17.6%) patients, respectively (p = 0.29). Conclusions: In this real-world cohort of patients with severe OSA and paroxysmal AF, higher objectively measured CPAP exposure was independently associated with delayed AF recurrence when analyzed as a continuous variable, suggesting a graded association between objectively measured CPAP exposure and AF recurrence. Larger studies with extended follow-up and continuous rhythm monitoring are warranted to confirm long-term rhythm benefits and effects on AF progression. Full article

Background: Palpitations are common in adolescents and often occur without structural heart disease. Although anxiety and autonomic dysregulation have been implicated, the role of micronutrient status remains unclear. This study aimed to investigate the association between palpitations, micronutrient levels, and anxiety in adolescents and to evaluate the independent associations between selected micronutrients and palpitations using multivariable regression models. Methods: This case–control study included 52 adolescents with palpitations and 52 frequency-matched healthy controls. Structural heart disease was excluded by electrocardiography, echocardiography, and 24-h Holter monitoring. Results: Adolescents with palpitations had significantly lower serum magnesium, selenium, and ferritin levels and higher anxiety scores than controls, despite most values remaining within reference ranges. In age- and sex-adjusted analyses, lower magnesium and selenium levels were independently associated with palpitations. Conclusions: Subclinical differences in micronutrient status, particularly magnesium and selenium, together with increased anxiety, may contribute to non-structural palpitations in adolescents. These findings support a more integrative evaluation that includes micronutrient and psychological assessment alongside standard cardiac investigations. Full article

Background: Cardiac arrhythmias are a frequent complication of acute SARS-CoV-2 infection. However, their long-term prevalence and clinical determinants among patients with post-COVID-19 syndrome, especially those previously hospitalized, remain poorly defined. Objectives: To assess the prevalence and types of arrhythmias in long COVID patients following hospitalization and to identify associated clinical risk factors. Methods: In this cross-sectional study, 53 patients previously hospitalized with confirmed COVID-19 were evaluated ≥3 months post-infection. All participants underwent a standardized clinical assessment, 12-lead electrocardiography, and 24 h Holter monitoring. Logistic and Cox regression analyses were performed to identify predictors of arrhythmia. Results: Arrhythmias were identified in 41.5% (n = 22) of patients. Atrial fibrillation (32%) was the most frequent arrhythmia, followed by sinus bradycardia (27%) and sinus tachycardia (18%). Age (OR 1.06, 95% CI 1.01–1.10, p = 0.01) and length of hospital stay (OR 1.1, 95% CI 1.01–1.2, p = 0.04) were independently associated with arrhythmia. Biguanide (metformin) therapy was inversely associated with the occurrence of arrhythmia (Exp(B) = 0.017, p = 0.008). Dyspnea (82.4%) and palpitations (41.5%) were the most commonly reported symptoms. Conclusions: Arrhythmias are common in patients with long COVID following severe disease. Advanced age and prolonged hospitalization are significant risk factors, while biguanide use may offer a protective effect. These findings underscore the need for targeted cardiac surveillance in this population. Full article

Atrial fibrillation (AF) is the most common sustained arrhythmia and a growing global health burden, yet conventional monitoring with Holter devices, event recorders and implantable loop recorders often fails to adequately capture recurrence. Rapid advances in digital health, wearable biosensors and artificial intelligence (AI) have transformed consumer smartwatches and wearables into potential clinical tools capable of continuous, real-world rhythm surveillance. This narrative review synthesizes contemporary evidence on smartwatch-based AF monitoring, spanning core technologies—photoplethysmography, single-lead electrocardiography and AI fusion algorithms—and validation studies across post-ablation follow-up. Compared with traditional modalities, smartwatch-based AF monitoring demonstrates improved detection of AF recurrence, enhanced characterization of AF burden, symptom–rhythm correlation, and greater patient engagement. At the same time, key limitations are critically examined, including motion artifacts, false-positive alerts, short recording windows, adherence dependence, digital literacy and access gaps, as well as unresolved issues around regulation, interoperability and data privacy. By integrating engineering advances with guideline-directed care pathways, smartwatch-based AF monitoring holds promise to complement, rather than immediately replace, established diagnostic tools and to enable more proactive, individualized AF management. Future work must focus on robust clinical validation, equitable implementation and clear regulatory frameworks to safely scale these technologies. Full article

Atrial fibrillation (AF) and ventricular arrhythmias (VAs) are common pathological arrhythmias of dogs and are both associated with a poor prognosis in those with cardiac disease. This study aimed to assess the ability of 2 to 5 min electrocardiography (routine ECG) to detect the presence and severity of concomitant VAs in dogs with secondary AF. Continuous 24 h ECG monitoring (Holter) was used as the reference standard to identify VAs, quantify the number of premature ventricular ectopic complexes (VPCs) and evaluate the degree of their organization using a modified Lown–Wolf classification scale. In light of the Holter findings, VAs were classified as severe based on two criteria: the presence of more than 100 VPCs and a Lown–Wolf grade ≥ 4. Thirty-five dogs with secondary AF were included, where all exhibited VAs on Holter monitoring. Most dogs had severe VAs, according to both the VPC count (69%) and Lown–Wolf classification (77%). However, only 13 dogs (37%) had VAs detectable on routine ECG. A significant positive correlation was found between the presence of VAs on routine ECG and the severity of VAs identified via Holter. Nevertheless, the diagnostic accuracy of routine ECG in predicting severe VAs was only moderate (68.6% based on VPC count and 60% based on Lown–Wolf grade). Overall, a 2 to 5 min ECG appears to be a highly specific but relatively insensitive tool for detecting VAs in dogs with secondary AF. 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: Early identification of left ventricular ejection fraction (LVEF) levels during the progression of hypertension is essential to prevent cardiac deterioration. However, achieving a non-invasive, cost-effective, and definitive assessment is challenging. It has prompted us to develop a comprehensive machine learning framework for the automatic quantitative estimation of LVEF levels from electrocardiography (ECG) signals. Methods: We enrolled 200 hypertensive patients from Zhongshan City, Guangdong Province, China, from 1 November 2022 to 1 January 2025. Participants underwent 24 h Holter monitoring and echocardiography for LVEF estimation. We developed a comprehensive machine learning framework that initiated with preprocessed ECG signal in one-hour intervals to extract CMSE-based heart rate variability (HRV) features, then utilized machine learning models such as linear regression (LR), Support Vector Machines (SVMs), and random forests (RFs) with recursive feature elimination for optimal LVEF estimation. Results: The LR model, notably during early night interval (20:00–21:00), achieved a RMSE of 4.61% and a MAE of 3.74%, highlighting its superiority. Compared with other similar studies, key CMSE parameters (Scales 1, 5, Slope 1–5, and Area 1–5) can effectively enhance regression models’ estimation performance. Conclusion: Our findings suggest that CMSE-derived circadian HRV features from Holter ECG could serve as a non-invasive, cost-effective, and interpretable solution for LVEF assessment in community settings. From a machine learning interpretable perspective, the proposed method emphasized CMSE’s clinical potential in capturing autonomic dynamics and cardiac function fluctuations. Full article

Background/Objectives: Atrial fibrillation (AF) remains a major risk factor for stroke. It is often asymptomatic and paroxysmal, making it difficult to detect with conventional electrocardiography (ECG). While photoplethysmography (PPG)-based devices like smartwatches have demonstrated efficacy in detecting AF, they are rarely integrated into hospital infrastructure. The study aimed to establish a seamless system for real-time AF screening in hospitalized high-risk patients using a wrist-worn PPG device integrated into a hospital’s data infrastructure. Methods: In this investigator-initiated prospective clinical trial conducted at the University Hospital Basel, patients with a CHA₂DS₂-VASc score ≥ 2 and no history of AF received a wristband equipped with a PPG sensor for continuous monitoring during their hospital stay. The PPG data were automatically transmitted, analyzed, stored, and visualized. Upon detection of an absolute arrhythmia (AA) in the PPG signal, a Holter ECG was administered. Results: The analysis encompassed 346 patients (mean age 72 ± 10 years, 175 females (50.6%), mean CHA₂DS₂-VASc score 3.5 ± 1.3)). The mean monitoring duration was 4.3 ± 4.4 days. AA in the PPG signal was detected in twelve patients (3.5%, CI: 1.5–5.4%), with most cases identified within 24 h (p = 0.004). There was a 1.3 times higher AA burden during the nighttime compared to daytime (p = 0.03). Compliance was high (304/346, 87.9%). No instances of AF were confirmed in the nine patients undergoing Holter ECG. Conclusions: This study successfully pioneered an automated infrastructure for AF screening in hospitalized patients through the use of wrist-worn PPG devices. This implementation allowed for real-time data visualization and intervention in the form of a Holter ECG. The high compliance and early AA detection achieved in this study underscore the potential and relevance of this novel infrastructure in clinical practice. Full article

Background and Objectives: Breast cancer (BC) is the most prevalent cancer globally, with a significant mortality rate, especially among women. While advances in treatment have reduced BC mortality, cardiovascular complications resulting from anticancer therapies have become a major concern. The autonomic nervous system (ANS) may be affected in BC patients and it is assessed with heart rate variability (HRV). The aim of this study was to investigate the prevalence of impaired HRV, its predictors, and its clinical impacts in BC patients. Materials and Methods: We retrospectively screened all female BC patients and enrolled cases who underwent 24 h Holter electrocardiography monitoring with accessible clinical follow-up data. Results: This study included 136 BC patients, and the mean age was 56.8 ± 10.8 years old. Impaired HRV was present in 36.8% of patients, and hypertension was identified as a significant predictor of reduced HRV (OR = 3.61, CI: 1.01–12.92, p = 0.048). Furthermore, de novo atrial fibrillation (AF) occurred more frequently in patients with impaired HRV (20% vs. 8.1%; p = 0.044). None of the HRV parameters were associated with all-cause mortality, and cancer stage was found to be the only independent predictor of all-cause mortality (HR = 3.93, CI: 1.81–8.55; p < 0.001). Conclusions: HRV is impaired in a significant proportion of patients with BC. Hypertension plays a crucial role in the deterioration of HRV in patients with BC, and de novo AF is more common in patients with impaired HRV. However, HRV does not appear to predict all-cause mortality in patients with BC. This study highlights the importance of the optimal management of cardiovascular risk factors, such as hypertension, to prevent ANS dysfunction in cancer patients. Full article

Background: The aim of this study was to evaluate the performance of the diagnostic pathway proposed by the European Society of Cardiology (ESC) guidelines for identifying the underlying aetiology of sudden cardiac death (SCD) through the screening of first-degree family members of patients with SCD who either had a negative autopsy or no autopsy performed. Methods: To be eligible for enrolment, patients had to meet the following inclusion criteria: a family history of SCD in a first-degree relative under the age of 50 years; the SCD decedents must not have undergone an autopsy, or if an autopsy was performed, non-cardiac and structural cardiac causes must have been excluded. Patients underwent a comprehensive assessment, including the evaluation of family and medical history, electrocardiography (ECG) and ECG with high precordial leads, Holter ECG monitoring, echocardiography, cardiac magnetic resonance imaging, and exercise stress testing. A sodium channel blocker test (i.e., flecainide test) was performed when other clinical investigations were negative and the suspicion of Brugada syndrome was high. Results: Forty-one patients from 25 different families fulfilled the inclusion criteria and represented the final study cohort. After the comprehensive diagnostic work-up, a total of seven patients from five different families (5/25, 20%) were diagnosed with an inherited cardiac condition: two families with arrhythmogenic right ventricular cardiomyopathy, one with dilated cardiomyopathy, one with non-dilated left ventricular cardiomyopathy, and one with long QT syndrome. Conclusions: The comprehensive cardiologic work-up of relatives of mainly young SCD victims results in the diagnosis of inherited cardiac conditions in one-fifth of cases. Full article

Hypertrophic cardiomyopathy (HCM) is a common heart disease in cats, characterized by regional or diffuse hypertrophy of the left ventricular walls, with an uncertain etiology and heterogenous natural history. Several types of rhythm disturbances are often associated with the disease. This study conducts a comprehensive review of the current literature, in order to evaluate the diagnostic and prognostic effectiveness of electrocardiography and Holter monitoring in the management of feline hypertrophic cardiomyopathy. The main subjects of discussion will include general information about HCM and its connection to arrhythmias. We will explore the rhythm disturbances documented in the current literature on Holter monitoring, as well as the techniques used for Holter monitoring. Additionally, the review will cover classical electrocardiography (ECG) and its diagnostic utility. Prognostic indicators and anti-arrhythmic therapy will also be discussed in detail. The findings highlight the importance of understanding arrhythmias in feline HCM for accurate diagnosis, risk assessment, and therapeutic intervention. ECG and Holter monitoring may offer valuable insights into managing feline HCM. Full article

Vital signs are crucial for assessing the condition of a patient and detecting early symptom deterioration. Noncontact sensor technology has been developed to take vital measurements with minimal burden. This study evaluated the accuracy of a mat-type noncontact sensor in measuring respiratory and pulse rates in patients with cardiovascular diseases compared to conventional methods. Forty-eight hospitalized patients were included; a mat-type sensor was used to measure their respiratory and pulse rates during bed rest. Differences between mat-type sensors and conventional methods were assessed using the Bland–Altman analysis. The mean difference in respiratory rate was 1.9 breaths/min (limits of agreement (LOA): −4.5 to 8.3 breaths/min), and proportional bias existed with significance (r = 0.63, p < 0.05). For pulse rate, the mean difference was −2.0 beats/min (LOA: −23.0 to 19.0 beats/min) when compared to blood pressure devices and 0.01 beats/min (LOA: −11.4 to 11.4 beats/min) when compared to 24-h Holter electrocardiography. The proportional bias was significant for both comparisons (r = 0.49, p < 0.05; r = 0.52, p < 0.05). These were considered clinically acceptable because there was no tendency to misjudge abnormal values as normal. The mat-type noncontact sensor demonstrated sufficient accuracy to serve as an alternative to conventional assessments, providing long-term monitoring of vital signs in clinical settings. Full article

Introduction: Obstructive sleep apnea (OSA) is associated with an increased risk of hypertension, coronary artery disease, heart failure (HF), and atrial fibrillation (AF). Materials and methods: A total of 179 patients aged 34–81 years were included in the study. The median age was 63 years (interquartile range: 56–69 years). Of these patients, 105 (58.7%) were men, and 74 (41.3%) were women; there were cases of paroxysmal (n = 99), persistent (n = 64), and permanent AF (n = 16). All patients underwent investigations including respiratory sleep monitoring, echocardiography, and 24 h Holter electrocardiography monitoring. Statistical analyses were performed using IBM SPSS Statistics 26.0. Results: OSA was detected in 131 (73.2%) patients. In patients with OSA, paroxysmal AF was commonest (n = 65), followed by persistent AF (n = 51) and permanent AF (n = 15). The patients with sleep apnea had increased body mass index (33.6 kg/m2; p = 0.02), waist circumference (114 cm; p < 0.001), and neck circumference (42 cm; p < 0.001) values. HF (OR 2.9; 95% CI: 1.4–5.9; p = 0.004) and type 2 diabetes (OR 3.6; 95% CI: 1.5–8.3; p = 0.001) were more common in patients with AF and OSA. The STOP-BANG scale (AUC = 0.706 ± 0.044; 95% CI: 0.619–0.792; p < 0.001) and the Berlin questionnaire (AUC = 0.699 ± 0.044; 95% CI: 0.614–0.785) had a higher predictive ability for identifying sleep apnea. Conclusions: Patients with AF demonstrate a high prevalence of OSA and an increased association with cardiovascular comorbidities. The STOP-BANG scale and the Berlin questionnaire can be used to screen for OSA in patients with AF. Full article

Background: Most recent clinical practice guidelines addressing the management of infantile hemangiomas (IHs) recommend oral propranolol, a non-selective beta-adrenergic antagonist, as first-line treatment. However, few reports have provided continuous follow-up data regarding cardiac evaluations. Methods: Sixty-four patients diagnosed with IHs and treated with oral propranolol before 2 years of age at the Department of Pediatrics, Kangbuk Samsung Hospital (Seoul, Republic of Korea), with regular examinations between 2017 and 2021, were included. Cardiac evaluations, including electrocardiography, Holter monitoring, chest X-ray, and echocardiography, were performed. Results: Sixty-four patients with IHs successfully underwent continuous follow-up cardiac evaluations. The median age at diagnosis was 2 weeks (1 day to 34.3 weeks). The median age at treatment initiation was 13.6 weeks (2.4–87.9 weeks), the mean longitudinal diameter of hemangioma at diagnosis was 2.8 ± 2.1 cm (0.3–12.0 cm), and the mean percentage of size decrease after 1 year of oral propranolol treatment was 71.8%. None of the 64 patients experienced severe adverse side effects during propranolol treatment. There was no statistically significant differences in echocardiographic function and electrocardiographic data after treatment. Conclusions: Propranolol treatment ≥6 months was effective and safe without significant cardiac toxicity in the treatment of patients with infantile hemangiomas. Full article