Validation of heart rate spot-check protocol to measure circadian variation and heart rate in healthy dogs and dogs with atrial fibrillation.

INTRODUCTION: Alternatives for out-of-clinic heart rate (HR) measurement are required to optimise the management of atrial fibrillation (AF) in dogs. Additionally, the presence of circadian variation (CV) in HR in pet dogs remains unknown. We aimed to identify the number and duration of spot-checks required for an accurate estimation of 24-hour HR in canine AF. Circadian variation in HR was examined in healthy dogs and dogs with AF, and spot-check-derived HR was compared with a CV-derived gold standard. MATERIALS AND METHODS: Ambulatory electrocardiogram data from healthy dogs and dogs with AF were retrospectively analysed. Heart rate was calculated from the entire recording and pre-defined periods (spot-checks) of one hour to 30 and 60 s in duration. Circadian variation in HR was determined by cosinor analysis. Bias and limits of agreement of means and median HR with mesor HR were determined by correlation and Bland-Altman analysis. RESULTS: Circadian variation in HR was identified not only in 18/22 healthy dogs and 14/21 AF dogs but only on ambulatory electrocardiogram recordings. Four-hourly spot-checks provided the most accurate estimate of mesor HR in healthy dogs (bias of the median over 30 s 7.70, limits of agreement 7.48), whereas, in dogs with AF, four, six and eight-hourly spot-checks provided reliable estimates of mesor HR (bias within -1.29 and -29.5). CONCLUSIONS: Four, six and eight-hourly HR spot-checks can estimate 24-hourly HR in dogs with AF. There was CV in HR in most healthy pet dogs and dogs with AF. Spot-check protocols cannot identify CV in HR.

Cross-instrument feasibility, validity, and reproducibility of wireless heart rate monitors: Novel opportunities for extended daily life monitoring.

Wired ambulatory monitoring of the electrocardiogram (ECG) is an established method used by researchers and clinicians. Recently, a new generation of wireless, compact, and relatively inexpensive heart rate monitors have become available. However, before these monitors can be used in scientific research and clinical practice, their feasibility, validity, and reproducibility characteristics have to be investigated. Therefore, we tested how two wireless heart rate monitors (i.e., the Ithlete photoplethysmography (PPG) finger sensor and the Cortrium C3 ECG monitor perform against an established wired reference method (the VU-AMS ambulatory ECG monitor). Monitors were tested on cross-instrument and test-retest reproducibility in a controlled laboratory setting, while feasibility was evaluated in protocolled ambulatory settings at home. We found that the Cortrium and the Ithlete monitors showed acceptable agreement with the VU-AMS reference in laboratory setting. In ambulatory settings, assessments were feasible with both wireless devices although more valid data were obtained with the Cortrium than with the Ithlete. We conclude that both monitors have their merits under controlled laboratory settings where motion artefacts are minimized and stationarity of the ECG signal is optimized by design. These findings are promising for long-term ambulatory ECG measurements, although more research is needed to test whether the wireless devices' feasibility, validity, and reproducibility characteristics also hold in unprotocolled daily life settings with natural variations in posture and activities.

Feasibility of P wave Centric Ambulatory Electrocardiogram Monitoring in Infants and Young Children.

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.

Comparison of Omegawave Device and an Ambulatory ECG for RR Interval Measurement at rest.

The aim of this study was to validate the measurements of the beat intervals taken at rest by the Omegawave® device by comparing them to an ambulatory electrocardiogram system. For this purpose, the electrocardiogram was digitally processed, time-aligned, and scrutinized for its suitable use as gold-standard. Rest measurements were made for 10 minutes on 5 different days to 10 men and 3 women (24.8±5.05 years; 71.82±11.02 kg; 174.35±9.13 cm). RR intervals were simultaneously recorded using the Omegawave device and a Holter electrocardiogram. The processing of Holter electrocardiogram signals included the detrending of baseline noise and a high-pass filtering for emphasizing the QRS complexes and attenuating the T waves. After obtaining the RR intervals from the electrocardiogram, those from the Omegawave device were automatically aligned to them with cross-correlation digital processing techniques and compared to check whether both measurements could be considered superimposable. A Bland-Altman analysis was applied to the 5 measurements made for all subjects. The Omegawave device exhibited very strong agreement with a quality-controlled Holter electrocardiogram. Deviations not exceeding 25 ms could be expected in 95% of the cases, which is within manageable ranges both for clinical practice and for sports.

Placement of Reveal LINQ Device in the Left Anterior Axillary Position.

Implantable loop recorders (ILR) are utilized for long-term rhythm monitoring. Typical placement of the Medtronic Reveal LINQ along the left parasternal border may compromise the quality and/or feasibility of future imaging studies. We sought to evaluate the utility of placing an ILR in the left anterior axillary position and the impact on the quality of cardiac imaging. We reviewed patients from May 2017 to June 2018 who had placement of a Reveal LINQ device in the left anterior axillary position. Demographic, procedural, and clinical data were collected via retrospective review. Cardiac magnetic resonance imaging (MRI) studies were reviewed for image quality after ILR placement. Eight patients met inclusion criteria for this study (median age 6 years, 50% female). Six patients (75%) had an ILR placed in the operating room, while all others were placed in the electrophysiology lab. All patients demonstrated acceptable R waves for diagnostic evaluation (median = 0.85 mV, range 0.24-1.7 mV). Cardiac MRI was obtained in 7 patients following ILR placement with diagnostic image quality and no adverse events. One device was explanted 28 days after placement due to concern for possible infection. No other devices required removal or revision (median follow up duration 11 months, IQR 8-13.5). ILR placement in the left anterior axillary position can record adequate signals in pediatric patients. In addition, axillary ILR device position may allow for completion of cardiac imaging, particularly cardiac MRI, without significant artifacts which is critical for patients with congenital heart disease.

Accuracy of wrist-worn heart rate monitors for rate control assessment in atrial fibrillation.

BACKGROUND: Wrist-worn heart rate (HR) monitors are increasingly popular. A paucity of data exists on their accuracy in atrial fibrillation (AF) in ambulatory patients. We sought to assess the HR accuracy of two commercially available smart watches [SW] (Fitbit Charge HR [FB] and Apple Watch Series 3 [AW]) compared with Holter monitoring in an ambulant patient cohort. METHODS: Thirty-two participants ≥18 years referred for 24-hour Holter monitoring were prospectively recruited. Each participant was randomly allocated to wear either a FB or AW along with their Holter monitor. RESULTS: Across all devices, 53,288 heart rate values were analysed from 32 participants. Twenty wore the AW (17 had persistent AF and 3 had sinus rhythm [SR]) while 12 participants wore the FB (9 in persistent AF and 3 in SR). Participants in SR demonstrated strong agreement compared to Holter monitoring (bias <1 beat, limits of agreement [LoA] -11 to 11 beats). In AF, both devices underestimated HR measurements (bias -9 beats, LoA -41 to 23). The degree of underestimation was more pronounced when HR > 100 bpm (bias of -28 beats for HR range 100-120 bpm, -48 for 120-140 bpm, and -69 for >140 bpm) compared to a slower HR (bias of -6 for HR range 80-100 bpm, <1 for 60-80 bpm, and -1 for <60 bpm). CONCLUSION: In ambulatory patients, smartwatches underestimated HR in AF particularly at HR ranges >100 bpm. Further improvements in device technology are needed before integrating them into the clinical management of rate control in AF.

RR interval signal quality of a heart rate monitor and an ECG Holter at rest and during exercise.

This study was designed to examine the RR interval signal qualities of a Holter device and a heart rate chest belt monitor at rest and during exercise. Ten healthy individuals completed five low- to high-intensity activities while simultaneously using the medilog® AR12plus Holter monitor and the Polar H10 heart rate monitor. The RR interval signal quality was based on the quantification of the missing RR intervals and RR interval detection errors. Therefore, both measurement systems were compared against visual inspection of the raw electrocardiography signal. The missing and wrong R-wave peak detections were counted manually for both measurement systems. RR interval signal quality was defined as the relative number of correctly detected RR intervals. Overall, RR interval signal qualities of 94.6% and 99.6% were demonstrated for the medilog® AR12plus and the Polar H10. During the high-intensity activities, the RR interval signal quality of the medilog® AR12plus dropped to 89.8%, whereas the Polar H10 maintained a signal quality of 99.4%. The correlation between both systems was high (r = 0.997, p > 0.001). The excellent RR interval signal quality during low- to moderate-intensity activities in the medilog® AR12plus and during low- to high-intensity activities in the Polar H10 demonstrates both measurement systems' validity for the detection of RR intervals throughout a wide range of activities. A simple chest strap such as the Polar H10 might be recommended as the gold standard for RR interval assessments if intense activities with strong body movements are investigated.

Qualitative and quantitative evaluation of a new wearable device for ECG and respiratory Holter monitoring.

BACKGROUND: Recent advances in wearable technology make continuous cardiorespiratory monitoring possible, with potential applications in assessment of cardiopulmonary patients, healthy subjects and athletes. The aim of the present study was to qualitatively and quantitatively evaluate a new wearable device (Learn Inspire Free Entertain = L.I.F.E.) by embedding in a compression shirt a 12­lead ECG system and 5 respiratory sensors. METHODS: Thirty cardiorespiratory patients and ten healthy subjects were studied for 24 h during their usual life activities. In 8 healthy subjects, simultaneous measurements of the device and of an ergo-spirometer were performed during different levels of ventilation in five different body positions. The quality of ECG signals in terms of measurability of heart rate, P wave, QRS complex and ST segment, was analyzed by four expert cardiologists/respiratory physiologists using an arbitrary 1-5 scale. The sum of the respiratory signals was used to calculate the respiratory rate, inspiratory time and relative changes of tidal volume. These parameters were compared to ergo-spirometer measurements. RESULTS: Median quality value was >3 for heart rate, QRS complex, ST segment and P wave (except in L3, aVL, aVF, V1 and V2 leads). Median quality of respiratory traces was >4 in patients and between 3 and 4 in healthy subjects. The respiratory monitoring of respiratory rate and inspiratory time was accurate in all body positions. Tidal volumes were underestimated due to a high level of ventilation. CONCLUSIONS: The L.I.F.E. device provides an accurate continuous monitoring of cardiorespiratory signals during the 24 h both in normal subjects and cardiorespiratory patients.

Ambulatory electrocardiogram monitoring for syncope and collapse: a comparative assessment of clinical practice in UK and Germany.

Aims: Diagnostic ambulatory electrocardiogram (AECG) monitoring is widely used for evaluating syncope/collapse. In Europe, two sets of practice guidelines [National Institute for Health and Clinical Excellence (NICE) and European Society of Cardiology (ESC)] provide recommendations concerning optimal selection of AECG devices. However, whether practising physicians' select AECGs based on published guidelines is unclear. This study examined AECG use by Emergency Department (EDs) physicians and cardiologists in two European countries: Germany (D) and United Kingdom (UK). Methods and Results: A quantitative survey was undertaken in which 177 respondents participated (ED: UK 33, Germany 40; Cardiology: UK 54, Germany 50). The choice of AECG technology varied by specialty. Thus, among EDs, despite patients having daily symptoms, 20% (UK), 31% (D) of respondents chose an AECG other than Holter monitor. Conversely, when monitoring for infrequent events (

The multiple arrhythmia dataset evaluation database (M.A.D.A.E.).

The convergence between wearable and medical device technologies is a natural progression. Miniaturization has allowed the design of small, compact monitoring systems that can record physiological signals over longer periods of time. Thus, the potential for these devices to expand the understanding of disease progression and patients' clinical status is very high. The accuracy of these devices, however, is dependent upon the computer algorithms utilized in the analysis of the large volume of physiological data monitored and/or recorded by the devices. Automated interpretation of the data by these new technologies, therefore, necessitates closer examination by regulatory organizations. The current requirements for the validation of novel Ambulatory ECG (A-ECG) annotation algorithms are based on the AAMI/ANSI-EC57 and IEC60601-2-47 Standard. These standards are being updated, but they rely on a very limited set of digitized ECG recordings from a couple of ECG databases built in the first half of the 70's. These reference signals are obsolete. We are developing a validation tool for computerized methods designed to detect and monitor cardiac activities based on body-surface ECGs. We will rely on a set of existing digital high-resolution 12­lead A-ECG recordings acquired in cardiac patients and healthy individuals. These ECG signals include a large and unique set of electrocardiographic events. This tool is being qualified by the Center for Devices and Radiological Health of the United States Food and Drug Administration (FDA) as a Medical Device Development Tool (MDDT). This document provides insights into the design of the M.A.D.A.E. database, its functionalities, and its ultimate role in enabling the next generations of automatic interpretation of ECG signals.

Comparison of one- and three-lead ECG to measure cardiac intervals and differentiate drug-induced multi-channel block.

INTRODUCTION: FDA has established initiatives to characterize clinical and non-clinical biomarkers to enable more precise prediction of proarrhythmia risk based upon knowledge of drug effect on multiple cardiac ion channels (Colatsky et al., 2016). The FDA has recently demonstrated superiority of early ventricular repolarization interval (JTp) in differentiating pure hERG block from multi-channel block in human subjects. Preclinical studies often acquire a single lead ECG, whereas FDA measurements of JTp were derived ​from a spatial vectorcardiogram computed using multiple leads. This study compares QT subintervals derived from single lead vs. spatial magnitude (SM) ECG and contrasts information obtained from multilead and single lead ECGs in the canine model. METHODS: Four beagle dogs were instrumented with 3-lead Holter monitors to acquire continuous surface ECG recordings for three consecutive days. A 24-h baseline recording was obtained on day 1 followed by administration of dofetilide on day 2 and atropine and dofetilide on day 3. Lead II and SM ECGs were automatically analyzed using the AE-1010 Rhythm Express™ (RE) software (VivaQuant, St. Paul, MN USA) without manual intervention or editing of the results (auto). Five-minute averages of beat-to-beat intervals measured on each lead were compared for agreement assessed by Bland-Altman (BA) statistics and consistency measured as the repeatability standard deviation (SD) from 5-min intervals. The fully automated results were screened by an operator (semi-automated) and compared to automated results. RESULTS: JTp and TpTe measured using SM lead are less sensitive to changes in posture and respiration related changes in T-wave morphology. The 24-h repeatability SD of 5-min subintervals for JTp and TpTe over the three days was improved by 15.4% and 15.5% respectively with the highest improvements of 23.3% for JTp on day 2 and 25.3% for TpTe on day 3. Drug induced changes in QTcV, QRS, RR, and PR intervals were qualitatively similar between the SM lead and Lead II and in close agreement based on BA statistics. Semi-automated and automated measurements from SM Lead were in close agreement based on BA statistics. DISCUSSION: Single lead ECG is adequate for PR, RR, QRS, and QT, but produces different and more variable results when assessing QT subintervals relative to the SM lead. Close agreement between automated and semi-automated measurements demonstrates Rhythm Express accuracy and the potential to streamline interval analysis.

Update to Practice Standards for Electrocardiographic Monitoring in Hospital Settings: A Scientific Statement From the American Heart Association.

BACKGROUND AND PURPOSE: This scientific statement provides an interprofessional, comprehensive review of evidence and recommendations for indications, duration, and implementation of continuous electro cardiographic monitoring of hospitalized patients. Since the original practice standards were published in 2004, new issues have emerged that need to be addressed: overuse of arrhythmia monitoring among a variety of patient populations, appropriate use of ischemia and QT-interval monitoring among select populations, alarm management, and documentation in electronic health records. METHODS: Authors were commissioned by the American Heart Association and included experts from general cardiology, electrophysiology (adult and pediatric), and interventional cardiology, as well as a hospitalist and experts in alarm management. Strict adherence to the American Heart Association conflict of interest policy was maintained throughout the consensus process. Authors were assigned topics relevant to their areas of expertise, reviewed the literature with an emphasis on publications since the prior practice standards, and drafted recommendations on indications and duration for electrocardiographic monitoring in accordance with the American Heart Association Level of Evidence grading algorithm that was in place at the time of commissioning. RESULTS: The comprehensive document is grouped into 5 sections: (1) Overview of Arrhythmia, Ischemia, and QTc Monitoring; (2) Recommendations for Indication and Duration of Electrocardiographic Monitoring presented by patient population; (3) Organizational Aspects: Alarm Management, Education of Staff, and Documentation; (4) Implementation of Practice Standards; and (5) Call for Research. CONCLUSIONS: Many of the recommendations are based on limited data, so authors conclude with specific questions for further research.

Variable Accuracy of Wearable Heart Rate Monitors during Aerobic Exercise.

PURPOSE: Athletes and members of the public increasingly rely on wearable HR monitors to guide physical activity and training. The accuracy of newer, optically based monitors is unconfirmed. We sought to assess the accuracy of five optically based HR monitors during various types of aerobic exercise. METHODS: Fifty healthy adult volunteers (mean ± SD age = 38 ± 12 yr, 54% female) completed exercise protocols on a treadmill, a stationary bicycle, and an elliptical trainer (±arm movement). Each participant underwent HR monitoring with an electrocardiogaphic chest strap monitor (Polar H7), forearm monitor (Scosche Rhythm+), and two randomly assigned wrist-worn HR monitors (Apple Watch, Fitbit Blaze, Garmin Forerunner 235, and TomTom Spark Cardio), one on each wrist. For each exercise type, HR was recorded at rest, light, moderate, and vigorous intensity. Agreement between HR measurements was assessed using Lin's concordance correlation coefficient (rc). RESULTS: Across all exercise conditions, the chest strap monitor (Polar H7) had the best agreement with ECG (rc = 0.996) followed by the Apple Watch (rc = 0.92), the TomTom Spark (rc = 0.83), and the Garmin Forerunner (rc = 0.81). Scosche Rhythm+ and Fitbit Blaze were less accurate (rc = 0.75 and rc = 0.67, respectively). On treadmill, all devices performed well (rc = 0.88-0.93) except the Fitbit Blaze (rc = 0.76). While bicycling, only the Garmin, Apple Watch, and Scosche Rhythm+ had acceptable agreement (rc > 0.80). On the elliptical trainer without arm levers, only the Apple Watch was accurate (rc = 0.94). None of the devices was accurate during elliptical trainer use with arm levers (all rc < 0.80). CONCLUSION: The accuracy of wearable, optically based HR monitors varies with exercise type and is greatest on the treadmill and lowest on elliptical trainer. Electrode-containing chest monitors should be used when accurate HR measurement is imperative.

Association of Implementation of Practice Standards for Electrocardiographic Monitoring With Nurses' Knowledge, Quality of Care, and Patient Outcomes: Findings From the Practical Use of the Latest Standards of Electrocardiography (PULSE) Trial.

BACKGROUND: Although continuous electrocardiographic (ECG) monitoring is ubiquitous in hospitals, monitoring practices are inconsistent. We evaluated implementation of American Heart Association practice standards for ECG monitoring on nurses' knowledge, quality of care, and patient outcomes. METHODS AND RESULTS: The PULSE (Practical Use of the Latest Standards of Electrocardiography) Trial was a 6-year multisite randomized clinical trial with crossover that took place in 65 cardiac units in 17 hospitals. We measured outcomes at baseline, time 2 after group 1 hospitals received the intervention, and time 3 after group 2 hospitals received the intervention. Measurement periods were 15 months apart. The 2-part intervention consisted of an online ECG monitoring education program and strategies to implement and sustain change in practice. Nurses' knowledge (N=3013 nurses) was measured by a validated 20-item online test, quality of care related to ECG monitoring (N=4587 patients) by on-site observation, and patient outcomes (mortality, in-hospital myocardial infarction, and not surviving a cardiac arrest; N=95 884 hospital admissions) by review of administrative, laboratory, and medical record data. Nurses' knowledge improved significantly immediately after the intervention in both groups but was not sustained 15 months later. For most measures of quality of care (accurate electrode placement, accurate rhythm interpretation, appropriate monitoring, and ST-segment monitoring when indicated), the intervention was associated with significant improvement, which was sustained 15 months later. Of the 3 patient outcomes, only in-hospital myocardial infarction declined significantly after the intervention and was sustained. CONCLUSIONS: Online ECG monitoring education and strategies to change practice can lead to improved nurses' knowledge, quality of care, and patient outcomes. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01269736.

Influence of food intake on the QT and QT/RR relation.

BACKGROUND: There are conflicting data on the influence of meal intake on the QT interval. METHODS: Ten healthy subjects were studied before and after a standardized breakfast and lunch with a sequence of supine resting, standing and exercise. Data collection was performed using a 12-lead Holter with semi-automated analysis. QT correction was performed using Fridericia (QTcF) correction formula and a subject-specific method based on individual QT/RR-regression (QTcI). RESULTS: Meal intake induced significant changes in HR (p<0.001), but not in QTcF (p=0.512) or QTcI (p=0.739). Postural analysis showed only significant differences in supine position for HR (p=0.010), not when standing or during exercise. CONCLUSION: Food intake induced an increase in heart rate limited to supine position. Using QTcF and QTcI no QTc changes were found.

Impact of standardized MONitoring for Detection of Atrial Fibrillation in Ischemic Stroke (MonDAFIS): Rationale and design of a prospective randomized multicenter study.

BACKGROUND: Atrial fibrillation (AF) is estimated to account for approximately every fifth ischemic stroke. In routine clinical practice, detection of undiagnosed, clinically silent AF represents a major diagnostic challenge, and in up to 30% of patients with ischemic stroke, AF remains undetected. The MonDAFIS study has been designed to quantify the diagnostic yield and clinical relevance of systematic electrocardiogram (ECG) monitoring for patients with acute ischemic stroke during the subsequent in hospital stay. STUDY DESIGN: A prospective randomized multicenter study in 3,470 patients with acute ischemic stroke or transient ischemic attack and without known AF on hospital admission. Over a period of approximately 2years, patients will be enrolled in about 30 German-certified stroke units and randomized 1:1 to receive either usual stroke unit diagnostic procedures for detection of AF (control group) or usual stroke unit diagnostic procedures plus standardized and centrally analyzed Holter ECG recording for up to 7days in hospital (intervention group). Results of the ECG core laboratory analysis will be provided to the patients and treating physicians. All patients will be followed up for treatment and cardiovascular outcomes at 6, 12, and 24months after enrollment. OUTCOMES: The primary outcome of the randomized MonDAFIS study is the proportion of patients who receive anticoagulation therapy 12months after the index stroke. Secondary outcomes include the number of stroke patients with newly detected AF in hospital and the rate of recurrent stroke, major bleedings, myocardial infarction, or death 6, 12, and 24months after the index event. MonDAFIS will also explore patient-reported adherence to anticoagulants, the clinical relevance of short atrial tachycardia, or excessive supraventricular ectopic activity as well as cost-effectiveness of prolonged, centrally analyzed ECG recordings. CONCLUSION: MonDAFIS will be the largest study to date to evaluate whether a prolonged and systematic ECG monitoring during the initial in hospital stay has an impact on secondary stroke prevention. In addition, prognosis as well as adherence to medication up to 2 years after the index stroke will be analyzed. The primary results of the MonDAFIS study may have the potential to change the current guidelines recommendations regarding ECG workup after ischemic stroke.

Arrhythmia Detection in Pediatric Patients: ECG Quality and Diagnostic Yield of a Patient-Triggered Einthoven Lead-I Event Recorder (Zenicor EKG-2™).

Symptoms that may be caused by arrhythmia are common in pediatric outpatient departments, though it remains challenging to reveal paroxysmal tachycardia. This investigation evaluated prospectively the quality and diagnostic yield of a newly available handheld patient-activated event recorder (ER) in children. In 226 children (pts) aged 0-17 years with or without congenital heart defects, pacemaker/ICDs or arrhythmia, a lead-I ER ECG was created. ER ECGs were recorded by pressing the patients' thumbs on the device and were analyzed in comparison with a lead-12 ECG, as gold standard. Event recording and data transmission were possible in all cases. ECG quality of the ER showed a high accordance in measuring heart rate (ICC = 0.962), duration of QRS complexes (κ = 0.686), and PR interval (ICC = 0.750) (p < 0.001) although P wave detection remained challenging (p = 0.120). 36 % (n = 82) of the pts had heart rhythm disturbances. The ER yielded 92 % sensitivity in diagnosing supraventricular tachycardia plus 77 % sensitivity and 92 % specificity in identifying abnormal ECGs. In children, the application of the tested ER was suitable. ECGs of good quality could be performed and transmitted easily, and also complex arrhythmia analysis was possible. This ER is an excellent diagnostic device for the detection and exclusion of tachycardia in children.