Holter Monitoring Research Articles

Exploring sleep heart rate variability: linear, nonlinear, and circadian rhythm perspectives.

Heart rate variability (HRV) is believed to possess the potential for disease detection. However, early identification of heart disease remains challenging, as HRV analysis in dogs primarily reflects the advanced stages of the disease. The aim of this study is to compare 24-h HRV with sleep HRV to assess the potential utility of sleep HRV analysis. Thirty healthy dogs with no echocardiographic abnormalities were included in the study, comprising 23 females and 7 males ranging in age from 2 months to 8 years (mean [standard deviation], 1.4 [1.6]). This study employed a cross-sectional study. 24-h HRV and sleep HRV were measured from 48-h Holter recordings. Both linear analysis, a traditional method of heart rate variability analysis, and nonlinear analysis, a novel approach, were conducted. Additionally, circadian rhythm parameters were assessed. In frequency analysis of linear analysis, the parasympathetic index nHF was significantly higher during sleep compared to the mean 24-h period (mean sleep HRV [standard deviation] vs. mean 24 h [standard deviation], 95% confidence interval, p value, r-family: 0.24 [0.057] vs. 0.23 [0.045], 0.006-0.031, p = 0.005, r = 0.49). Regarding time domain analysis, the parasympathetic indices SDNN and RMSSD were also significantly higher during sleep (SDNN: 179.7 [66.9] vs. 156.6 [53.2], 14.5-31.7, p < 0.001, r = 0.71 RMSSD: 187.0 [74.0] vs. 165.4 [62.2], 13.2-30.0, p < 0.001, r = 0.70). In a geometric method of nonlinear analysis, the parasympathetic indices SD1 and SD2 showed significantly higher values during sleep (SD1: 132.4 [52.4] vs. 117.1 [44.0], 9.3-21.1, p < 0.001, r = 0.70 SD2: 215.0 [80.5] vs. 185.9 [62.0], 17.6-40.6, p < 0.001, r = 0.69). Furthermore, the circadian rhythm items of the parasympathetic indices SDNN, RMSSD, SD1, and SD2 exhibited positive peaks during sleep. The findings suggest that focusing on HRV during sleep can provide a more accurate representation of parasympathetic activity, as it captures the peak circadian rhythm items.

Value of Extended Arrhythmia Screening in Adult Congenital Heart Disease Patients.

The European Society of Cardiology guidelines for the management of adult congenital heart disease patients recommend screening for arrhythmias and bradycardias in symptomatic patients, often being done by means of an ambulatory 24-48-hour Holter or implantable loop recorder (ILR). However, nowadays non-invasive instruments, such as patches, smartwatches and smartphones based on single-lead ECGs that perform extended monitoring, are also available. The aim of this narrative review was to assess whether these instruments, when they detect arrhythmias and bradycardias in patients with adult congenital heart disease, will lead to meaningful changes in clinical care. Clinically meaningful changes include adjustment of medication, cardioversion, electrophysiology study, ablation or implantation of a cardiovascular implantable electronic device. The following monitoring instruments are discussed: cumulative Holter, 2-week continuous monitor, smartwatchand smartphone-based single-lead ECG, and ILR. The diagnostic yield of extended rhythm monitoring is high, and varies between 18% (smartphone-based single-lead ECG) and 41% with ILR. In conclusion, contemporary arrhythmia screening includes various new non-invasive technologies that are promising new tools as an alternative to Holter monitoring or ILR. However, the optimal mode of detection is still unclear due to the lack of head-to-head comparisons.

Hypertension as predictive factor for bevacizumab-containing first-line therapy in metastatic breast and colorectal cancer in BRECOL (GEICAM/2011-04) study

BackgroundRetrospective data suggest an association between bevacizumab efficacy and the incidence of arterial hypertension (AHT). Additionally, epigenetic mechanisms have been related to AHT.MethodsThis prospective observational study conducted by GEICAM Spanish Breast Cancer Research Group included metastatic breast (MBC) or colorectal (mCRC) cancer patients treated with bevacizumab-containing chemotherapy as first-line treatment. Blood pressure (BP) levels were measured (conventional and 24-h Holter monitoring) at baseline and up to cycle 3. Primary endpoint assessed BP levels increase as predictive factor for progression-free survival (PFS). Germline DNA methylation profile was explored in pre-treatment blood samples; principal component analysis was used to define an epigenetic predictive score for increased BP levels.ResultsFrom Oct-2012 to Jul-2016, 143 (78 MBC and 65 mCRC) patients were included. The incidence of AHT according to guidelines was neither predictive of PFS nor of best overall tumor response (BOR). No statistically significant association was observed with systolic BP nor diastolic BP increment for PFS or BOR. Grade 3 and 4 adverse events were observed in 37 and 5% of patients, respectively. We identified 27 sites which baseline methylation status was significantly associated to BP levels increase secondary to bevacizumab-containing chemotherapy.ConclusionsNeither the frequency of AHT nor the increase of BP levels were predictive of efficacy in MBC and mCRC patients treated with bevacizumab-containing chemotherapy.Clinical trial registryClinicalTrials.gov Identifier: NCT01733628.

An artificial intelligence-enabled Holter algorithm to identify patients with ventricular tachycardia by analysing their electrocardiogram during sinus rhythm.

Ventricular tachycardia (VT) is a dangerous cardiac arrhythmia that can lead to sudden cardiac death. Early detection and management of VT is thus of high clinical importance. We hypothesize that it is possible to identify patients with VT during sinus rhythm by leveraging a continuous 24 h Holter electrocardiogram and artificial intelligence. We analysed a retrospective Holter data set from the Rambam Health Care Campus, Haifa, Israel, which included 1773 Holter recordings from 1570 non-VT patients and 52 recordings from 49 VT patients. Morphological and heart rate variability features were engineered from the raw electrocardiogram signal and fed, together with demographical features, to a data-driven model for the task of classifying a patient as either VT or non-VT. The model obtained an area under the receiving operative curve of 0.76 ± 0.07. Feature importance suggested that the proportion of premature ventricular beats and beat-to-beat interval variability was discriminative of VT, while demographic features were not. This original study demonstrates the feasibility of VT identification from sinus rhythm in Holter.

The effect of potassium levels on electrocardiographic data in calves with neonatal diarrhea

Objective: The objective of the current study was to assess the potassium levels and electrocardiographic (ECG) data in a cohort of 40 calves (age &lt; 30 days) diagnosed with newborn diarrhea, originating from dairy farms located in Ankara, Turkey.&#x0D; Materials and Methods: This study was conducted on a dairy farm located in Ankara, involving a population of 500 dairy animals. The calves were divided into two groups: one group with normal potassium levels (n=24) and another group with hyperkalemia (n=16) due to neonatal diarrhea. After the initial clinical examination was conducted on the farm, electrocardiographic investigations were carried out utilizing an ECG equipment. The biochemical analysis of blood samples that were collected in red and dry collecting tubes was carried out with the assistance of an automated analyzing machine &#x0D; Results: The findings indicate that there were no statistically significant differences observed across all ECG variables between the two groups.&#x0D; Conclusion: Acidemia and metabolic acidosis are commonly observed in calves suffering from hyperkalemic diarrhea, as documented in previous investigations, often accompanied by heart rhythm problems. In contrast, the current investigation revealed that neonatal calves with diarrhea and hyperkalemia had just a deepening of the T wave, without any additional abnormalities. Nevertheless, it is important to note that acidemia and metabolic acidosis were not of a severe nature. The implementation of Holter monitoring is indicated for calves experiencing hyperkalemia in conjunction with diarrhea.

Low rates of myocardial fibrosis and ventricular arrhythmias in recreational athletes after SARS-CoV-2 infection.

High rates of cardiac involvement were reported in the beginning of the coronavirus disease 2019 (COVID-19) pandemic. This led to anxiety in the athletic population. The current study was set up to assess the prevalence of myocardial fibrosis and ventricular arrhythmias in recreational athletes with the recent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Consecutive adult recreational athletes (≥18 years old, ≥4 h of mixed type or endurance sports/week) underwent systematic cardiac evaluation after a prior confirmed COVID-19 infection. Evaluation included clinical history, electrocardiogram (ECG), 5-day Holter monitoring, and cardiac magnetic resonance (CMR) imaging with simultaneous measurement of high-sensitive cardiac Troponin I. Data from asymptomatic or mildly symptomatic athletes (Group 1) were compared with those with moderate to severe symptoms (Groups 2-3). Furthermore, a comparison with a historical control group of athletes without COVID-19 (Master@Heart) was made. In total, 35 athletes (18 Group 1, 10 female, 36.9 ± 2.2 years, mean 143 ± 20 days following diagnosis) were evaluated. The baseline characteristics for the Group 1 and Groups 2-3 athletes were similar. None of the athletes showed overt myocarditis on CMR based on the updated Lake Louise criteria for diagnosis of myocarditis. The prevalence of non-ischemic late gadolinium enhancement [1 (6%) Group 1 vs. 2 (12%) Groups 2-3; p = 0.603] or ventricular arrhythmias [1 Group 1 athlete showed non-sustained ventricular tachycardia (vs. 0 in Groups 2-3: p = 1.000)] were not statistically different between the groups. When the male athletes were compared with the Master@Heart athletes, again no differences regarding these criteria were found. In our series of recreational athletes with prior confirmed COVID-19, we found no evidence of ongoing myocarditis, and no more detection of fibrosis or ventricular arrhythmias than in a comparable athletic pre-COVID cohort. This points to a much lower cardiac involvement of COVID-19 in athletes than originally suggested.

The diagnostic efficiency of artificial intelligence based 2 hours Holter monitoring in premature ventricular and supraventricular contractions detection.

Electrocardiography (ECG) and 24 hours Holter monitoring (24 h-Holter) provided valuable information for premature ventricular and supraventricular contractions (PVC and PSVC). Currently, artificial intelligence (AI) based 2 hours single-lead Holter (2 h-Holter) monitoring may provide an improved strategy for PSVC/PVC diagnosis. AI combined with single-lead Holter monitoring improves PSVC/PVC detection. In total, 170 patients were enrolled between August 2022 and 2023. All patients wore both devices simultaneously; then, we compared diagnostic efficiency, including the sensitivity/specificity/positive predictive-value (PPV) and negative predictive-value (NPV) in detecting PSVC/PVC by 24 h-Holter and 2 h-Holter. The PPV and NPV in patients underwent 2 h-Holter were 76.00%/87.50% and 96.35%/98.55, respectively, and the sensitivity and specificity were 79.17%/91.30%, and 95.65%/97.84% in PSVC/PVC detection compared with 24 h-Holter. The areas under the ROC curves (AUCs) for PSVC and PVC were 0.885 and 0.741, respectively (p < .0001). The potential advantages of the 2 h-Holter were shortened wearing period, improved convenience, and excellent consistency of diagnosis.

Значение лучевых методов в диагностике ишемической болезни сердца у конкретного пациента

Purpose: Demonstrate a clinical observation in which to establish a diagnosis it was necessary to use eight methods for diagnosing coronary pathology, four of which are radiation. Material and methods: To establish a diagnosis in a cardiac patient with suspected coronary heart disease (CHD), post-infarction cardiosclerosis, echocardiography (ECG), Holter monitoring (HM), bicycle ergometry (VE), X-ray computed tomography (X-ray computed tomography) to determine calcification of the coronary arteries, single-photon selective computer tomography (SPECT), magnetic resonance computed tomography (MRI), positron emission computed tomography (PET), coronary angiography (CAG). Results: The sequential use of eight diagnostic methods, four from radiation, was established when observing cardiosclerosis with coronary heart disease, cardiosclerosis in the 4, 5, 10, and 11 segments of the heart, complicated by a left ventricular aneurysm in the lower and lateral walls with minor ischemia at the height of physical activity. The need to use SPECT/CT in the complex diagnosis of coronary heart disease consists of using hybrid tomography and sequentially performing two studies in one diagnostic procedure (X-ray computed tomography and SPECT with 99m Tc-technetril) it seems possible to obtain 26 study indicators (with X-ray computed tomography – 4 indicators assessing calcification of the coronary arteries, with SPECT – 11 indicators of perfusion and 11 indicators of myocardial function). Conclusion: A clinical observation of the diagnosis of coronary artery disease with post-infarction cardiosclerosis and left ventricular aneurysm was demonstrated in which eight diagnostic technologies were used (ECG, CM, VE, CT, SPECT, MRI, PET, and CAG), four of which relate to radiation diagnostics (X-ray CT, SPECT, PET, and KAG). A feature of sequential hybrid tomography (X-ray CT and SPECT with 99mTc-technitrile) is that this technology allows you to obtain 26 research indicators.

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.

Accelerated Idioventricular Rhythm in Acute Coronary Syndrome with ST Segment Elevation: Clinical Significance

Background: Accelerated Idioventricular rhythm in acute coronary syndrome with ST segment elevation is common after thrombolysis and it is relatively benign; its occurrence is considered as a sign of reperfusion of the occluded coronary artery. Aims: The main objective of our study is the determination of the frequency of Accelerated Idioventricular rhythm in acute coronary syndrome with ST segment elevation after thrombolysis, the secondary objective is checking with coronary angiography if this rhythm really means the success of thrombolysis and reperfusion of the occluded coronary artery. Methods and materials: In this prospective study, conducted in the cardiology department of Hussein Dey hospital (Algiers-Algeria), 467 patients with acute coronary syndrome with elevated ST segment (87 women and 380 men) were enrolled between 28 February 2014 and 16 July 2015. The average age is 60 ± 13 years; at admission, a Holter recorder was attached in 448 patients, for continuous ECG monitoring during 48 hours, coronary angiography was performed in 329 patients. Kruskal’s ANNOVA or H tests were used for comparison of quantitative variables, χ2 test or Fisher’s exact test, were used for qualitative variables, all tests were performed with 1st species risk of 5%. Results: The frequency of Accelerated idioventricular rhythm recorded by the Holter ECG is 17.2 % (77 patients), CI 95%: [13.7%-20.7%], this frequency is 18.71 % (73 patients) CI 95%: [14.8 %-22.6%] in patients undergoing thrombolytic treatment. There is no significant difference between the frequencies of persistence of chest pain in the groups of patients with or without accelerated idioventricular rhythm after thrombolysis: 5.47 % (4 patients) versus 5.99 % (19 patients) respectively, p = 0.979; also for the frequencies of persistence of ST segment elevation after thrombolysis: 4.10 % (3 patients) versus 6.94 % (22 patients) respectively, p = 0.476). The frequency of occluded coronary artery (TIMI 0) is low in group of patients with accelerated idioventricular rhythm 14.51 %, (9 patients) compared to group of patients without this rhythm 21.39 % (52 patients), but the difference isn’t significant (p= 0.227). Conclusion: Accelerated idioventricular rhythm is common in acute coronary syndrome with elevated ST segment and generally considered as a sign of reperfusion; in our study, this rhythm may occur even in the absence of reperfusion of the occluded coronary artery and does not necessarily mean reperfusion or success of thrombolysis.

THE VALUE OF HOLTER MONITORING AND THE LEVEL OF SYSTEMIC INFLAMMATION IN PATIENTS WITH STABLE ISCHEMIC HEART DISEASE COMBINED WITH TYPE 2 DIABETES, DEPENDING ON THE NUMBER OF AFFECTED CORONARY ARTERIES

Diabetes mellitus (DM) is one of the significant medical and social problems of modern society, which is due to high morbidity and prevalence, frequent occurrence of chronic micro- and macrovascular complications. Coronary heart disease (CHD) in patients with type 2 diabetes is 2-4 times more common than in people of the same age without diabetes [1]. In the absence of apparent signs of atherosclerosis, the risk of developing coronary artery disease in the next 10 years is 30% [2]. To date, the course and prognosis of this group of patients have not been sufficiently studied, objective clinical and diagnostic criteria for the development of complications of myocardial infarction have not been developed, and the problem of choosing pathogenetically based methods of treatment of CHD in combination with type 2 diabetes remains unresolved [3].The aim of the work was to investigate the informativeness of Holter monitoring (HM), the correlation of HM indicators, C-reactive protein (CRP) and carbohydrate metabolism in patients with stable coronary heart disease (CHD) in combination with type 2 diabetes for the prognosis of the course of this pathology, timely individual treatment and prevention occurrence of endpoints.Material and methods. The study involved 95 patients with coronary heart disease with angina pectoris functional class (FC) III and heart failure (HF FC III with a preserved left ventricular ejection fraction (LVEF); of them, 60 patients had concomitant type 2 DM in the compensation stage.Results. In patients with comorbidity (a combination CHD and type 2 diabetes), episodes of ST depression/elevation, tachycardia, and extrasystoles were more often registered in patients with multivessel lesions of CA (р&lt;0.05), according to HM; the content of CRP in blood serum increased in proportion to the severity of the course of the disease, which depended on the number of affected CA.Conclusions. The nature and severity of the course of CHD correlate with comorbid pathology and the number of CAs affected by atherosclerosis. In the case of multivessel damage, according to the data of clinical, functional and laboratory research, an aggressive progression of cardiac pathology was noted.

High Prevalence of Atrial Fibrillation Found in the Capital of Greenland When Using Continuous Electrocardiogram Monitoring: A Cross-Sectional Study

BackgroundAtrial fibrillation (AF) increases the risk of conditions such as ischemic stroke, dementia, and heart failure, and early detection is crucial. In Greenland, ischemic strokes are common, and the prevalences of AF risk factors are increasing. Studies based on 30-second electrocardiograms (ECGs) and diagnosis codes so far have indicated either a low prevalence of AF or a prevalence comparable to that in other Western countries, such as Denmark. However, using short, single-point ECGs may underestimate the true prevalence, as especially paroxysmal AF can be missed. With this study, we aim to estimate the prevalence of AF using 3-5–day continuous Holter recordings among people in Nuuk, the capital of Greenland. MethodsIn this cross-sectional study, we estimated the prevalence of AF among the population aged ≥ 50 years in Greenland’s capital, Nuuk. We used an ePatch to record continuous ECGs for 3-5 days, and questionnaires to assess demographic data, comorbidities, medication, symptoms, and risk factors for AF. ResultsOf 226 participants (62% women), 21 (33% women) had either self-reported AF, AF on the recording, or both, equivalent to a prevalence of 9.3% (confidence interval [CI] 5.8-13.9). The age-stratified prevalence was 7.2% (CI 2.7-15.1) among those aged 50-59 years; 8.8% (CI 4.1-16.1) among those aged 60-69 years; and 18.2% (CI 7.0-35.5) among those aged ≥ 70 years. ConclusionsThis study provides a novel insight into AF prevalence in Nuuk, emphasizing the potential underestimation in previous studies. Continuous ECG monitoring revealed a higher prevalence, especially among the younger age groups, urging a reevaluation of diagnostic practices in this unique population.

Impact of left ventricular hypertrophy on frequency and complexity of ventricular arrhythmia among hypertensive Egyptian patients

BackgroundLeft ventricular hypertrophy (LVH) is associated with an increased risk of ventricular arrhythmias and cardiovascular mortality. The study objective was to investigate the effect of LVH severity on the complexity and severity of ventricular arrhythmias among a subset of Egyptian hypertensive patients.ResultsThe study cohort consisted of 60 hypertensive patients with LVH as diagnosed by echocardiography. Their mean age was (53.7 ± 12.3) years. 36 males (40%) and 24 females (60%). Diabetes mellitus was found in 26 patients (43%), 41% of these cases were smokers. 48-h Holter monitoring was performed in all cases to assess the frequency of ventricular premature contractions (VPC) and their complexity using the Lown grading. Increasing posterior wall thickness end diastole (PWTd) was an independent predictor of increasing VPC frequency, each 1 mm increase in the PWTd is associated with a 1.26% increase in the VPC% among total heart beats (b = 12.6, p < 0.001). Higher-grade VPCs—defined as grade 4a, 4b, and 5—were seen in 29 patients (48.3%). Interventricular septum thickness end diastole, PWTd, left ventricular mass, and left ventricular mass index (LVMI), were significantly higher among patients with higher Lown grading (p < 0.001). Using logistic regression analysis, female sex and LVMI were independent predictors of more complex VPC (OR = 8.766, p = .014), (OR = 1.096, p < 0.001), respectively. Among females, LVMI of more than 120 g/m2 can differentiate between high- and low-grade VPCs with 71% sensitivity and 80% specificity, while among males, LVMI of more than 129.5 g/m2 can differentiate between high and low-grade VPCs with 86% sensitivity and 66% specificity.ConclusionsThe frequency and complexity of ventricular arrhythmias among hypertensive heart disease are correlated with the severity of ventricular hypertrophy. Female sex and increasing left ventricular mass index are independent predictors of more complex forms of ventricular arrhythmias.

Idiopathic Premature Ventricular Contraction Catheter Ablation, Sedentary Population vs. Athlete's Populations: Outcomes and Resumption of Sports Activity.

There are no investigations about the outcomes of idiopathic PVC catheter ablation (CA) in athletes compared to the sedentary population. We conducted a prospective single-centre observational study. The primary and secondary procedural outcomes were the post-ablation reduction of premature ventricular contractions (PVCs) in an athletes vs. non-athletes group and in agonist vs. leisure-time athletes. The third was the evaluation of the resumption of physical activity and the improvement of symptoms in agonist and leisure-time athletes. From January 2020 to October 2022 we enrolled 79 patients with RVOT/LVOT/fascicular PVC presumed origin. The median percentage of decrease between the pre-procedure and post-procedure Holter monitoring in the non-athletes group was 96 (IQR 68-98) and 98 in the athletes group (IQR 92-99) (p = 0.08). Considering the athletes, the median percentage of decrease in the number of PVCs was 98 (IQR 93-99) and 98 (IQR 87-99), respectively, in leisure-time and agonistic athletes (p = 0.42). Sixteen (70%) leisure time and seventeen (90%) agonist athletes (p = 0.24) have resumed physical activity 3 months after PVC CA; among agonistic athletes, 59% have resumed competitive physical activity. Many leisure-time (88%) and agonist (70%) athletes experienced an improvement in symptoms after ablation. PVC CA was effective and safe in both groups, reducing symptoms and allowing a quick and safe return to sports activities in athletes.

48 hours holter monitoring in detecting occult atrial fibrillation in Adults

48 hours holter monitoring in detecting occult atrial fibrillation in Adults

Three-Day Monitoring of Adhesive Single-Lead Electrocardiogram Patch for Premature Ventricular Complex: Prospective Study for Diagnosis Validation and Evaluation of Burden Fluctuation.

Wearable electrocardiogram (ECG) monitoring devices are used worldwide. However, data on the diagnostic yield of an adhesive single-lead ECG patch (SEP) to detect premature ventricular complex (PVC) and the optimal duration of wearing an SEP for PVC burden assessment are limited. We aimed to validate the diagnostic yield of an SEP (mobiCARE MC-100, Seers Technology) for PVC detection and evaluate the PVC burden variation recorded by the SEP over a 3-day monitoring period. This is a prospective study of patients with documented PVC on a 12-lead ECG. Patients underwent simultaneous ECG monitoring with the 24-hour Holter monitor and SEP on the first day. On the subsequent second and third days, ECG monitoring was continued using only SEP, and a 3-day extended monitoring was completed. The diagnostic yield of SEP for PVC detection was evaluated by comparison with the results obtained on the first day of Holter monitoring. The PVC burden monitored by SEP for 3 days was used to assess the daily and 6-hour PVC burden variations. The number of patients additionally identified to reach PVC thresholds of 10%, 15%, and 20% during the 3-day extended monitoring by SEP and the clinical factors associated with the higher PVC burden variations were explored. The recruited data of 134 monitored patients (mean age, 54.6 years; males, 45/134, 33.6%) were analyzed. The median daily PVC burden of these patients was 2.4% (IQR 0.2%-10.9%), as measured by the Holter monitor, and 3.3% (IQR 0.3%-11.7%), as measured in the 3-day monitoring by SEP. The daily PVC burden detected on the first day of SEP was in agreement with that of the Holter monitor: the mean difference was -0.07%, with 95% limits of agreement of -1.44% to 1.30%. A higher PVC burden on the first day was correlated with a higher daily (R2=0.34) and 6-hour burden variation (R2=0.48). Three-day monitoring by SEP identified 29% (12/42), 18% (10/56), and 7% (4/60) more patients reaching 10%, 15%, and 20% of daily PVC burden, respectively. Younger age was additionally associated with the identification of clinically significant PVC burden during the extended monitoring period (P=.02). We found that the mobiCARE MC-100 SEP accurately detects PVC with comparable diagnostic yield to the 24-hour Holter monitor. Performing 3-day PVC monitoring with SEP, especially among younger patients, may offer a pragmatic alternative for identifying more individuals exceeding the clinically significant PVC burden threshold.

Electrocardiographic and Autonomic Nervous System Changes after Changes in the Posture of Children and Adolescents with Duchenne Muscular Dystrophy.

Duchenne Muscular Dystrophy (DMD) is a rare inherited neuromuscular disease. At first, cardiac involvement may be asymptomatic. Therefore, assessing patients using non-invasive methods can help detect any changes. Analyze the electrocardiogram (ECG) test and heart rate variability (HRV) of the DMD group and compare the information with that of the age-matched control group. A prospective study with 27 male patients with DMD (11.9 years old), who underwent clinical evaluation, ECG, echocardiogram, and Holter monitoring. ECG (200% increase) was assessed by two independent observers. HRV was measured over time (24 h) and in the frequency domain, in the supine and sitting positions. The healthy group consisted of nine patients (11.0 years old). A value of p < 0.05 was considered statistically significant. The mean ejection fraction (EF) was 60% (34 to 71%). The Kappa coefficient for ECG measurements ranged from 0.64 to 1.00. An increase in the R/S ratio in V1 was observed in 25.9% of the subjects, pathological Q wave in 29.6%, and fragmented QRS in 22.2% in inferior/high lateral regions, with a negative correlation with EF (p = 0.006). There was low HRV, without the influence of any variable, including treatment. With the change in position, there was an increase in HR (p = 0.004), but there was no change in HRV. The LF/HF ratio was 2.7 in the DMD group and 0.7 in the control group (p = 0.002). In DMD subjects, prominent R waves in V1 and changes in the inferior/high lateral regions occurred in almost 30% of the cases. Lower vagal tone was observed without the influence of the variables age, ejection fraction, QT dispersion, and treatment. Despite the increase in HR, there was no adequate HRV response to the change in position.

Efficacy and safety of antiarrhythmic therapy in dogs with naturally acquired tachyarrhythmias treated with amiodarone or sotalol: a retrospective analysis of 64 cases

Introduction/objectiveStudies on the use of amiodarone or sotalol are limited in dogs. Therefore, this study aimed to provide data on the efficacy and safety of these drugs in dogs with ventricular tachyarrhythmia (VT) and/or supraventricular tachyarrhythmia (SvT). Animals, materials, and methodsDogs with VT and/or SvT treated with amiodarone or sotalol as a first-line therapy were retrospectively evaluated. Signalment, clinical, diagnostic, therapeutic, and outcome data were retrieved. For VT, efficacy was demonstrated through a decrease of the Lown-Wolf grade to less than five or a reduction of at least 85% in the number of ventricular premature complexes observed on Holter monitoring. For SvT, efficacy was represented by cardioversion or a reduction in the mean heart rate on Holter monitoring ≤140 beats/min. Treatment-related side effects (TRSEs) were classified as clinically relevant and irrelevant. Statistical analysis was performed to compare data before and after antiarrhythmic prescription. ResultsSixty-four dogs were included. Amiodarone and sotalol were efficacious in treating both VT (85.7% and 90.0% of cases, respectively) and SvT (75% and 71.4% of cases, respectively). No significant differences were found when comparing their efficacy rates in dogs with VT and SvT (P=0.531 and 0.483, respectively). Clinically relevant TRSEs were rare with both amiodarone and sotalol (8.3% and 5% of cases, respectively), while clinically irrelevant TRSEs occurred more frequently with amiodarone (29.2%) than with sotalol (10%). DiscussionIn dogs with tachyarrhythmias, amiodarone and sotalol are generally efficacious and safe, as clinically relevant TRSEs seem rare. ConclusionsThis study provides novel data on the effects of amiodarone and sotalol in dogs with tachyarrhythmias.

Abstract P241: Stress-Induced Autonomic Dysfunction is Associated With Mental Stress-Induced Myocardial Ischemia in Patients With Coronary Artery Disease

Background: Mental stress-induced myocardial ischemia (MSIMI) is associated with adverse cardiovascular outcomes in individuals with coronary artery disease (CAD), but the mechanisms underlying this phenomenon are unknown. We examined the relationship between stress-induced autonomic dysfunction, measured by lower heart rate variability (HRV) in response to stress, and MSIMI in patients with stable CAD. We hypothesized that stress-induced autonomic dysfunction is associated with higher odds of MSIMI. Methods: In 735 participants with stable CAD, we measured high frequency (HF) and low frequency (LF) HRV in 5-minute intervals before and during a standardized laboratory-based speech stressor using Holter monitoring. MSIMI was evaluated with single-photon emission computed tomography myocardial perfusion imaging. HRV at rest and stress were categorized into low (lowest quartile) versus high (upper three quartiles) categories; low category was used as an indicator of autonomic dysfunction. Multivariable logistic regression models were used to examine the association of autonomic dysfunction with MSIMI. Results: The mean age was 58 (SD ±10) years, 35% were women, 44% were Black participants, and 16% developed MSIMI. Compared with high stress HRV, low stress HRV (both HF and LF) was associated with higher odds of MSIMI after adjusting for demographic and clinical factors. LF HRV at rest was also significantly associated with MSIMI with slightly reduced effect estimates. Conclusions: In individuals with CAD, mental stress-induced autonomic dysfunction may be an independent mechanism in the pathogenesis of MSIMI.

An association between heart rate variability and pediatric obstructive sleep apnea

BackgroundThere are different findings on heart rate variability (HRV) and pediatric obstructive sleep apnea (pOSA) by an overnight HRV or a 1-hr HRV. However, there is limited data of HRV and pOSA diagnosis by using a 24-h HRV test. This study aimed to evaluate if HRV had potential for OSA diagnosis by using a 24-h HRV test.MethodsThis was a prospective study included children age between 5 and 15 years old, presenting with snoring, underwent polysomnography and a 24-h Holter monitoring. Predictors for pOSA diagnosis were analyzed using logistic regression analysis.ResultsDuring the study period, there were 81 pediatric patients met the study criteria. Of those, 65 patients (80.25%) were diagnosed as OSA. There were three factors were independently associated with OSA: standard deviation of all normal interval (SDNN), high frequency (HF), and low frequency (LF). The adjusted odds ratios of these factors were 0.949 (95% confidence interval 0.913, 0.985), 0.786 (95% confidence interval 0.624, 0.989), and 1.356 (95% confidence interval 1.075, 1.709).ConclusionsHRV parameters including SDNN, HF, and LF were associated with pOSA diagnosis in children by using the 24-h Holter monitoring.