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To evaluate heart rate (HR), the presence of extrasystoles and other Holter findings among healthy newborns, and to collect data for new normal limits for Holter parameters in newborns. For this cross-sectional study, 70 healthy term newborns were recruited to undergo 24-h Holter monitoring. Linear regression analysis was used in HR analyses. The age-specific limits for HRs were calculated using linear regression analysis coefficients and residuals. The mean (SD) age of the infants was 6.4 (1.7) days during the recording. Each consecutive day of age raised the minimum and mean HR by 3.8 beats per minute (bpm) (95% CI: 2.4, 5.2; P <.001) and 4.0 bpm (95% CI: 2.8, 5.2; P <.001), respectively. Age did not correlate with maximum HR. The lowest calculated limit for minimum HR ranged from 56 bpm (aged 3 days) to 78 bpm (aged 9 days). A small number of atrial extrasystoles and ventricular extrasystoles were observed in 54 (77%) and 28 (40%) recordings, respectively. Short supraventricular or ventricular tachycardias were found in 6 newborns (9%). Conclusion: The present study shows an increase of 20 bpm in both the minimum and mean HRs of healthy term newborns between the 3rd and 9th days of life. Daily reference values for HR could be adopted in the interpretation of HR monitoring results in newborns. A small number of extrasystoles are common in healthy newborns, and isolated short tachycardias may be normal in this age group. What is Known: • The current definition of bradycardia in newborns is 80 beats per minute. • This definition does not fit into the modern clinical setting of continuously monitored newborns, where benign bradycardias are commonly observed. What is New: • A linear and clinically significant increase in heart rate was observed in infants between the ages of 3 and 9 days. • It appears as though lower normal limits for heart rate could be applied to the youngest newborns. [ABSTRACT FROM AUTHOR]

We aimed to demonstrate the feasibility of 90-day cardiac monitoring with an external Holter device and to find a target population able to benefit from such a technique. Cryptogenic stroke patients were continuously monitored for 90 days with a textile wearable Holter (TWH). Compliance and quality of the monitoring were assessed by the number of hours of ECG stored per month. Mean predictors of pAF, including age, gender, stroke severity, and atrial size (LAVI), were evaluated. One-year follow-up assessed pAF detection outside per protocol monitoring. Out of 224 patients included in 5 stroke centers, 163 patients (72.76%) fulfilled the criteria for the protocol. Median monitoring time was similar among the three months. Per protocol pAF detection reached 35.37% at 90 days. The age (OR 1.095; 95% CI 1.03–1.14) and the LAVI (OR 1.055; 95% CI 1.01–1.09) independently predicted pAF. The cut-off point of 70 years (AUC 0.68) (95% CI 0.60–0.76) predicted pAF with a sensitivity of 75.8% and specificity of 50.5%. The LAVI cut-off point of 28.5 (AUC 0.67) (95% CI 0.56–0.77) had a sensitivity of 63.6% and a specificity of 61.8% to detect pAF. The combination of both markers enhanced the validity of pAF detection sensitivity to 89.6%, with a specificity of 27.59%. These patients had increased risk of pAF during the 90-day monitoring HR 3.23 (χ2 7.15) and beyond 90 days (χ2 5.37). Intensive 90-days TWH monitoring detected a high percentage of pAF. However, a significant number of patients did not complete the monitoring. Patients older than 70 years and with enlarged left atria benefitted more from the protocol. [ABSTRACT FROM AUTHOR]

Frequent ventricular ectopy (VE) ≥ 10% in children with structurally normal hearts and the development of ventricular dysfunction is not well described. We aim to describe frequent VE ≥ 10% in children with structurally normal hearts and characterize the development of dysfunction. Patients with VE burden ≥ 10% on 24-h Holter performed between 2010 and 2019 were included in this retrospective review. Patients with structural heart disease and cardiomyopathy preceding the onset of VE were excluded. Medical records, electrocardiogram, Holter, and transthoracic echocardiogram data were analyzed. Patients were classified based on maximum VE burden on Holter (“frequent” 10–29% versus “very frequent” ≥ 30%), presence of runs of VE, VE morphology on ECG, coupling interval, and development of dysfunction. Two hundred thirty-four patients met inclusion criteria, 187 with frequent VE and 47 with very frequent VE. Seventeen (7%) patients developed ventricular dysfunction, the majority of whom had mild dysfunction. Very frequent VE > 30% and non-sustained ventricular tachycardia (NSVT) on Holter were associated with dysfunction. There was no association between coupling interval or prematurity index and dysfunction. Ventricular dysfunction is uncommon in children with structurally normal hearts and frequent VE burden > 10%, though VE burden > 30% and presence of NSVT were associated with dysfunction. Previously described characteristics to delineate higher risk VE based on coupling interval were not associated with dysfunction. [ABSTRACT FROM AUTHOR]

P wave centric ambulatory electrocardiographic (ECG) monitoring has emerged as an important tool aiding the diagnosis of arrhythmias. However, their efficacy and user experience in infants and young children are not well established. A retrospective study was performed to detail clinical and user experience of ECG monitoring using the Carnation Ambulatory Monitor (CAM) patch (Bardy Diagnostics Inc., Seattle, WA) in patients less than 10 kg. Additionally, 2 different monitor locations (over the sternum and horizontal over the left axilla) were assessed to address the optimal placement in these patients. A total of 33 CAM reports from 25 patients, aged 0 to15 months were included in the study. Mean patient age was 4.2 months ± 5.0 and mean weight was 5.3 kg ± 2.4. Thirty-six percent of patients (9/25) had known congenital heart disease. Indications for monitoring included: tachyarrhythmia (15/33, 45%), bradyarrhythmia (6/33, 18%), ectopic rhythm (9/33, 27%), cardiac tumor (1/33, 1%), and prolonged QT interval (1/33, 1%). All CAM reports showed clear, identifiable P waves which were diagnostic and lead to changes in medical management for 30% of patients (e.g., medication adjustments or discharge from cardiology care). We found the upright placement over the sternum performed better than the horizontal placement over the left axilla for small infants and children less than 10 kg. A P wave centric single-lead ECG monitor is helpful in providing accurate diagnostics tracings in infants and small children aiding in their clinical management. [ABSTRACT FROM AUTHOR]

Background: Direct-acting antiviral agents (DAAs) cure patients with hepatitis C virus (HCV) infection. Concerns have arisen the occurrence of significant bradyarrhythmias during treatment with DAAs. The aim of this study was to assess the impact of a DAA combination for the treatment of HCV infection on heart rate, rhythm, and heart rate variability (HRV) using 24-h ECG monitoring. Results: A prospective randomized study of 50 treatment-naïve patients with HCV infection treated with a combination of sofosbuvir 400 mg daily and daclatasvir 60 mg daily for 12 weeks. Surface ECG and 24-h ECG monitoring were performed at baseline and after completion of therapy to assess PR interval, corrected QT interval (QTc), minimum heart rate (HR), maximum HR, average HR, HRV time-domain and frequency-domain measures, significant pauses, tachycardias, bradycardias, premature atrial contractions (PACs), and premature ventricular contraction (PVCs). No differences were detected in all examined parameters between baseline and after completion of treatment. PR interval was 154 ± 25.95 vs 151.4 ± 23.82 ms, respectively (p = 0.124). QTc interval was 397.34 ± 29.38 vs 395.04 ± 30.23 ms, respectively (p = 0.403). No differences were detected for minimum HR, maximum HR, average HR, HRV time-domain and frequency-domain measures, the occurrence of significant pauses, sinus tachycardia episodes, sinus bradycardia episodes, PACs, and PVCs. No episodes of bradyarrhythmias, syncope, and atrial fibrillation, supraventricular, or ventricular tachycardias were reported or detected. Conclusion: In non-cardiac patients receiving no cardioactive medications, the combination of sofosbuvir and daclatasvir for the treatment of HCV infection has no effect on HR, rhythm, conductivity, or HRV. No symptomatic bradycardias, tachycardias, or syncope were reported or detected using 24-h ECG monitoring. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this analysis was to investigate the potential for ulixertinib (BVD-523) to prolong cardiac repolarization. The mean prolongation of the corrected QT (QTc) interval was predicted at the mean maximum drug concentrations of the recommended phase 2 dose (RP2D; 600 mg BID) and of higher concentrations. In addition, the effect of ulixertinib on other quantitative ECG parameters was assessed.Methods: In a two-part, phase 1, open-label study in adults with advanced solid tumors, 105 patients [24 in Part 1 (dose escalation) and 81 in Part 2 (cohort expansion)] were included in a QT prolongation analysis. Electrocardiograms (ECGs) extracted from 12-lead Holter monitors, along with time-matched pharmacokinetic blood samples, were collected over 12 h on cycle 1 day 1 and cycle 1 day 15 and analyzed by a core ECG laboratory.Results: A small increase in heart rate was observed on both study days (up to 5.6 bpm on day 1 and up to 7 bpm on day 15). The estimated mean changes from baseline in the study-specific QTc interval (QTcSS), at the ulixertinib Cmax, were - 0.529 ms (90% CI - 6.621, 5.562) on day 1 and - 9.202 ms (90% CI - 22.505, 4.101) on day 15. The concentration: QTc regression slopes were mildly positive but not statistically significant [0.53 (90% CI - 1.343, 2.412) and 1.16 (90% CI - 1.732, 4.042) ms per µg/mL for days 1 and 15, respectively]. Ulixertinib had no meaningful effect on PR or QRS intervals.Conclusions: Ulixertinib administered to patients with solid tumors at clinically relevant doses has a low risk for QT/QTc prolongation or any other effects on ECG parameters.Registration: The study is registered at Clinicaltrials.gov (NCT01781429) and was sponsored by BioMed Valley Discoveries. [ABSTRACT FROM AUTHOR]

Background: Premature ventricular beats (PVBs) are early depolarization of the myocardium originating in the ventricle. In case of very frequent PVBs, patients are severely symptomatic with impaired quality of life and are at risk of pre-syncope, syncope, heart failure, and sudden cardiac death particularly in the presence of structural heart disease. Ventricular outflow tracts are the most common sites of origin of idiopathic PVBs especially in patients without structural heart disease. We examined the role of radiofrequency catheter ablation in suppression of monomorphic PVBs of outflow tract origin in the presence or absence of structural heart disease, and its impact on improvement of left ventricular (LV) systolic function. Methods: Thirty-seven highly symptomatic patients with PVBs burden exceeding 10% were enrolled, provided that PVBs are monomorphic, originating in ventricular outflow tracts and regardless the presence or absence of structural heart disease. Patients were divided into 2 groups according to PVB site origin (RVOT vs. LVOT). 3D electro-anatomical mapping modalities were used in all patients employing activation mapping technique in the majority of cases. Acute success was considered when PVBs completely disappeared or when residual sporadic PVBs ≤ 1 beats/min or ≤10 beats/30 min after RF ablation. Patients were followed up for a mean period of 5.4 ± 1.2 months with long-term success defined as complete disappearance or marked reduction by more than 75% in the PVBs absolute number on 24 h holter monitoring. Results: Mean age of the study group was 39.9 ± 12.97 years, including 22 (59.4%) males. PVBs originated in RVOT in 17 cases and in LVOT in the remaining 20 cases. Prevalence of structural heart disease and consequently shortness of breath was higher in LVOT group. Initial ECG localization matched EP localization in the majority (94%) of cases. R wave duration index was the only significant independent predictor for RVOT origin with cut off value of <0.3 (P = 0.0057) upon multivariate analysis. Acute success was encountered in 32 (86%) patients with all cases of failure in the LVOT group. Recurrence occurred in 5 (15%) cases without significant difference between both groups. All cases of recurrence had residual PVBs at the end of the procedure. 18 cases out of the study group showed significant improvement of their EF (>5%) at the end of the follow-up period with no significant differences between both groups (p = 0.09). A linear correlation was observed between PVBs burden at follow up and magnitude of improvement of LV EF, particularly in patients with resting LV dysfunction and increased LV internal dimensions. Conclusions: RF ablation is an effective and safe method for elimination of outflow tract PVBs irrespective of their origin and the presence or absence of structural heart disease. PVBs burden after ablation appears to be the main determinant for reversal of PVB induced myopathy particularly in those with increased LV internal dimensions. [ABSTRACT FROM AUTHOR]

The evaluation of the stroke and transient ischemic attack (TIA) patient has been historically predominated by the initial evaluation in the hospital setting. As the etiology of stroke has eluded us in approximately one third of all acute events, the medical community has been eager to seek the answer to this mystery. In recent years, we have seen an explosion of innovations and trends allowing for a more detailed post stroke assessment strategy aimed at the identification of occult atrial fibrillation as the etiologic cause for the cryptogenic event. This has been achieved through the evolution and aggressive application and study of prolonged and advanced cardiac monitoring. This review is aimed to clarify and elucidate the standard and novel cardiac monitoring methods that have become available for use by the medical community and expected in the higher level care of cryptogenic stroke and TIA patients. These cardiac monitoring methods and devices are as heterogeneous as our patient population and have their own advantages and disadvantages. Many factors may be taken into consideration in choosing the appropriate cardiac monitoring method and are highlighted for consideration in this review. With a judicious approach to investigating the cryptogenic stroke population, and applying a wealth of novel treatment options, we may move forward into a new era of stroke prevention. [ABSTRACT FROM AUTHOR]

Patients with ischemic stroke and atrial fibrillation (AF) are treated with long-term oral anticoagulation (OAC) because it is considerably more effective than antiplatelet (AP) therapy for the prevention of subsequent strokes and systemic emboli. Therefore, detecting AF changes therapy and makes secondary prevention more effective. Technology for detection of rare episodes of paroxysmal AF (PAF) has improved recently. AF that is only detectable by prolonged monitoring (occult AF, or oAF) may underlie some strokes of unknown cause (cryptogenic stroke). However, the ideal method and duration of cardiac monitoring to detect oAF after stroke is unknown. Furthermore, new technologies allow the detection of brief, rare episodes of AF that would not have been detectable at the time classic studies establishing the benefit of OAC were conducted. Therefore, it is unknown what the minimum threshold of oAF burden or duration is that mandates OAC instead of AP therapy. Here we review the available technologies, and discuss the therapeutic implications and uncertainties when oAF is found after ischemic stroke. There is evidence that 3 weeks of outpatient cardiac telemetry has a high yield of detection of AF after cryptogenic stroke; however, ongoing studies may show that even longer monitoring periods have higher yield. [ABSTRACT FROM AUTHOR]

Abstract: Finding the cause of syncope represents a major medical challenge. Interrogation of the patient where possible, combined with medical examination and good knowledge of the relative incidence of the different types of syncope are essential elements to identify the true origin of the faint. Concerning rhythmic syncopes (with a prevalence of “only” 10–15%), the first step is to avoid false association between syncope and arrhythmia on the ECG. From one person to another, there can be wide difference in the ability to tolerate a slow or a rapid arrhythmia. [Copyright &y& Elsevier]

A random sample of 457 neonates was prospectively studied in order to identify the incidence, common types, and risk factors for arrhythmias in the neonatal intensive care unit (NICU). A 12-lead EKG was studied in all neonates ( n = 457). A total of 139 Holter studies was done in every fourth baby with a normal EKG ( n = 100) and in all babies with an abnormal EKG ( n = 39). Of the 100 infants who were thought to be arrhythmia-free by EKG, nine infants demonstrated an arrhythmia on Holter studies. When we correlated screening results with maternal, obstetrical, and neonatal risk factors; arrhythmias were significantly associated with male gender, more mature gestational age, lower glucose levels, maternal smoking, high umbilical artery lines, and the use of the nebulized β-2 adrenergic treatment, whereas umbilical venous lines and dopamine infusion did not relate to arrhythmia. We conclude that arrhythmias are more common in the NICU than in the general neonatal population. Compared to Holter monitoring, the sensitivity of the EKG was only 89%. [ABSTRACT FROM AUTHOR]

The metoprolol CR/Zok is a multi-unit formulation containing metoprolol succinate controlled release (CR/Zok) in the form of individual drug delivery units (microcapsules). Each microcapsule acts as a diffusion cell and is designed to deliver metoprolol succinate at a near constant rate for about 20 hours independently of food intake, pH and other physiological variations. Taking the half-life of metoprolol into account this yields an even plasma concentration over 24 hours with a once daily dosage scheme. The formulation allows for once daily dosing, avoiding peaks and troughs in the plasma concentration of the drug. This leads to an even beta1-blockade over 24 hours in dose ranges from 12.5 mg to 200 mg once daily. Plasma fluctuations are considerably decreased compared with immediate release formulations and cardioselectivity is well maintained also on 200 mg CR/Zok. Vital important beta1-blockade is maintained for 24 hours. Metoprolol CR/Zok is well tolerated and well-being has been shown to be improved with metoprolol CR/Zok in patients with chronic heart failure as illustrated in the findings from the MERIT-HF study. [ABSTRACT FROM AUTHOR]

Effective initial identification of potential cardiac arrhythmias in symptomatic children is difficult due to the infrequency, brief duration, and vague nature of subjective complaints in the young. Although both telephone event and Holter monitoring are used for this purpose, no comparative studies of the initial screening efficacy of either have been performed. A total of 202 consecutive symptomatic children (age 11 days to 26 years, mean 10.2 years) were evaluated for potential cardiac arrhythmias with either 24-h Holter (97 patients) or telephone event (105 patients) recorders and grouped according to the presence or absence of congenital heart defects, normal or abnormal resting electrocardiogram (ECG), and presence or absence of cardiac surgery. The results showed 30% of all recordings (61% event; 14% Holter) failed to substantiate any arrhythmias in spite of subjective symptoms. Event recordings showed a better correlation of sensed symptoms with arrhythmias (32%) compared to Holters (5%) ( p<0.01) with 73% of Holter recordings performed during both asymptomatic and arrhythmia-free 24-h periods. Holter monitoring was more effective in detecting nonsensed and asymptomatic events (8% versus 0.5%, ( p<0.01), among high-risk children. This study demonstrates that although both monitoring devices are applicable to children, each has inherent limitations and usefulness. These must be considered in choosing either device to permit their most optimal and cost-effective application. [ABSTRACT FROM AUTHOR]