Clinical validation and evaluation of a novel six-lead handheld electrocardiogram recorder compared to the 12-lead electrocardiogram in unselected cardiology patients (EVALECG Cardio)

Utility and acceptability of remote 6-lead electrocardiographic monitoring in children with inherited cardiac conditions

OBJECTIVE

This pilot study sought to investigate the utility and acceptability of the KardiaMobile 6-lead ECG (KM6LECG) as a tool for remote monitoring in children with inherited cardiac conditions.

DESIGN

A single-centre prospective cohort study. Children underwent standard clinical evaluation including a 12-lead ECG and a KM6LECG in the clinic. Participants recorded KM6LECGs monthly at home for 3 months. Families completed a questionnaire on their experience.

SETTING

Great Ormond Street Hospital Centre for Inherited Cardiovascular Diseases.

PARTICIPANTS

64 children: 22 with hypertrophic cardiomyopathy (HCM); 22 with long QT syndrome and 20 unaffected siblings (controls).

MAIN OUTCOME MEASURES

Comparison of data extracted from the clinic 12-lead ECG and supervised KM6LECG, and the supervised and unsupervised KM6LECG recording.

RESULTS

Of 64 children (35% female, mean age 12 years), 58 had a baseline 12-lead ECG and appropriate baseline KM6LECG. In children with HCM, abnormalities in ventricular depolarisation/repolarisation in the limb leads of the 12-lead ECG were reliably reproduced. From the whole cohort, there was a strong positive correlation between the corrected QT interval from the 12-lead ECG and baseline KM6LECG (intraclass correlation coefficient=0.839) and baseline KM6LECG with an unsupervised KM6LECG (intraclass correlation coefficient=0.736). Suspected 'lead' misplacement impacted 18% of unsupervised recordings. Overall, the acceptability of the KM6LECG to families was good.

CONCLUSIONS

The KM6LECG provides an accurate tool for assessing some ECG abnormalities associated with paediatric inherited cardiovascular disease and may provide a useful at-home adjunct to face-to-face clinical care of children requiring ECG assessment.

Feasibility and accuracy of mobile QT interval monitoring strategies in bedaquiline-enhanced prophylactic leprosy treatment

Some anti-mycobacterial drugs are known to cause QT interval prolongation, potentially leading to life-threatening ventricular arrhythmia. However, the highest leprosy and tuberculosis burden occurs in settings where electrocardiographic monitoring is challenging. The feasibility and accuracy of alternative strategies, such as the use of automated measurements or a mobile electrocardiogram (mECG) device, have not been evaluated in this context. As part of the phase II randomized controlled BE-PEOPLE trial evaluating the safety of bedaquiline-enhanced post-exposure prophylaxis (bedaquiline and rifampicin, BE-PEP, versus rifampicin, SDR-PEP) for leprosy, all participants had corrected QT intervals (QTc) measured at baseline and on the day after receiving post-exposure prophylaxis. The accuracy of mECG measurements as well as automated 12L-ECG measurements was evaluated. In total, 635 mECGs from 323 participants were recorded, of which 616 (97%) were of sufficient quality for QTc measurement. Mean manually read QTc on 12L-ECG and mECG were 394 ± 19 and 385 ± 18 ms, respectively (p < 0.001), with a strong correlation (r = 0.793). The mean absolute QTc difference between both modalities was 11 ± 10 ms. Mean manual and automated 12L-ECG QTc were 394 ± 19 and 409 ± 19 ms, respectively (n = 636; p < 0.001), corresponding to moderate agreement (r = 0.655). The use of a mECG device for QT interval monitoring was feasible and yielded a median absolute QTc error of 8 ms. Automated QTc measurements were less accurate, yielding longer QTc intervals.

KardiaMobile 6L versus 12-lead ECG: Effects on clinic utilization time

INTRODUCTION

We aimed to study whether KardiaMobile 6L 30-second capture technology could shorten ECG collection time compared to standard 12L ECG without compromising data usability.

METHODS

A single-center, non-randomized trial was performed on patients presenting for follow-up visits to the electrophysiology (EP) clinic. Providers in the KardiaMobile 6L group were allowed to request a standard 12L if the 6L was deemed insufficient for clinical care. Room utilization times, defined as the time from medical assistant room entry to exit, were compared for each group.

RESULTS

There were 100 patients in the study, with 50 in each arm. Average room utilization time for the 12L group and 6L groups were 10.33 ± 2.2 and 7.27 ± 1.93 min, respectively (p < .001). In 8 (16%) visits for the 6L group, an additional 12L was requested.

CONCLUSION

For EP follow-up visits, clinic utilization time was significantly reduced with the KardiaMobile 6L compared to the 12L ECG with infrequent need for an additional 12L.

Validation of a Handheld 6-Lead Device for QT Interval Monitoring in Resource-Limited Settings

Importance

Rifampin-resistant tuberculosis treatment regimens require electrocardiographic (ECG) monitoring due to the use of multiple QTc-prolonging agents. Formal 12-lead ECG devices represent a significant burden in resource-constrained clinics worldwide and a potential barrier to treatment scale-up in some settings.

Objective

To evaluate the diagnostic accuracy of a handheld 6-lead ECG device within resource-constrained clinics.

Design, Setting, and Participants

This diagnostic study was performed within a multicenter, pragmatic (broad eligibility criteria with no exclusions for randomized participants), phase 3 rifampin-resistant tuberculosis treatment trial (BEAT Tuberculosis [Building Evidence for Advancing New Treatment for Tuberculosis]) in South Africa. A total of 192 consecutive trial participants were assessed, and 191 were recruited for this substudy between January 21, 2021, and March 27, 2023. A low proportion (3 of 432 [0.7%]) of all screened trial participants were excluded due to a QTc interval greater than 450 milliseconds. Triplicate reference standard 12-lead ECG results were human calibrated with readers blinded to 6-lead ECG results.

Main Outcomes and Measures

Diagnostic accuracy, repeatability, and feasibility of a 6-lead ECG device.

Results

A total of 191 participants (median age, 36 years [IQR, 28-45 years]; 81 female participants [42.4%]; 91 participants [47.6%] living with HIV) with a median of 4 clinic visits (IQR, 3-4 visits) contributed 2070 and 2015 12-lead and 6-lead ECG assessments, respectively. Across 170 participants attending 489 total clinic visits where valid triplicate QTc measurements were available for both devices, the mean 12-lead QTc measurement was 418 milliseconds (range, 321-519 milliseconds), and the mean 6-lead QTc measurement was 422 milliseconds (range, 288-574 milliseconds; proportion of variation explained, R2 = 0.4; P < .001). At a QTc interval threshold of 500 milliseconds, the 6-lead ECG device had a negative predictive value of 99.8% (95% CI, 98.8%-99.9%) and a positive predictive value of 16.7% (95% CI, 0.4%-64.1%). The normal expected range of within-individual variability of the 6-lead ECG device was high (±50.2 milliseconds [coefficient of variation, 6.0%]) relative to the 12-lead ECG device (±22.0 milliseconds [coefficient of variation, 2.7%]). The mean (SD) increase in the 12-lead QTc measurement during treatment was 10.1 (25.8) milliseconds, with 0.8% of clinic visits (4 of 489) having a QTc interval of 500 milliseconds or more.

Conclusions and Relevance

This study suggests that simplified, handheld 6-lead ECG devices are effective triage tests that could reduce the need to perform 12-lead ECG monitoring in resource-constrained settings.

KardiaMobile 6L for measuring QT interval in people having antipsychotic medication to inform early value assessment: a systematic review

Background

The indication for this assessment is the use of the KardiaMobile six-lead electrocardiogram device for the assessment of QT interval-based cardiac risk in service users prior to the initiation of, or for the monitoring of, antipsychotic medications, which are associated with an established risk of QT interval prolongation.

Objectives

To provide an early value assessment of whether KardiaMobile six-lead has the potential to provide an effective and safe alternative to 12-lead electrocardiogram for initial assessment and monitoring of QT interval-based cardiac risk in people taking antipsychotic medications.

Review methods

Twenty-seven databases were searched to April/May 2022. Review methods followed published guidelines. Where appropriate, study quality was assessed using appropriate risk of bias tools. Results were summarised by research question; accuracy/technical performance; clinical effects (on cardiac and psychiatric outcomes); service user acceptability/satisfaction; costs of KardiaMobile six-lead.

Results

We did not identify any studies which provided information about the diagnostic accuracy of KardiaMobile six-lead, for the detection of corrected QT-interval prolongation, in any population. All studies which reported information about agreement between QT interval measurements (corrected and/or uncorrected) with KardiaMobile six-lead versus 12-lead electrocardiogram were conducted in non-psychiatric populations, used cardiologists and/or multiple readers to interpret electrocardiograms. Where reported or calculable, the mean difference in corrected QT interval between devices (12-lead electrocardiogram vs. KardiaMobile six-lead) was generally small (≤ 10 ms) and corrected QT interval measured using KardiaMobile six-lead was consistently lower than that measured using 12-lead electrocardiogram. All information about the use of KardiaMobile six-lead, in the context of QT interval-based cardiac risk assessment for service users who require antipsychotic medication, was taken from retrospective surveys of staff and service users who had chosen to use KardiaMobile six-lead during pilots, described in two unpublished project reports. It is important to note that both these project reports relate to pilot studies which were not intended to be used in wider evaluations of KardiaMobile six-lead for use in the NHS. Both reports included survey results which indicated that the use of KardiaMobile six-lead may be associated with reductions in the time taken to complete an electrocardiogram and costs, relative to 12-lead electrocardiogram, and that KardiaMobile six-lead was preferred over 12-lead electrocardiogram by almost all responding staff and service users.

Limitations

There was a lack of published evidence about the efficacy of KardiaMobile six-lead for initial assessment and monitoring of QT interval-based cardiac risk in people taking antipsychotic medications.

Conclusions

There is insufficient evidence to support a full diagnostic assessment evaluating the clinical and cost effectiveness of KardiaMobile six-lead, in the context of QT interval-based cardiac risk assessment for service users who require antipsychotic medication. The evidence to inform the aims of this early value assessment (i.e. to assess whether the device has the potential to be clinically effective and cost-effective) was also limited. This report includes a comprehensive list of research recommendations, both to reduce the uncertainty around this early value assessment and to provide the additional data needed to inform a full diagnostic assessment, including cost-effectiveness modelling.

Study registration

This study is registered as PROSPERO CRD42022336695.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Evidence Synthesis programme (NIHR award ref: NIHR135520) and is published in full in Health Technology Assessment; Vol. 28, No. 19. See the NIHR Funding and Awards website for further award information.

S, Poddubskaya E, Novikova A, Bykova A, Kopylov P. A single-lead ECG based cardiotoxicity detection in patients on polychemotherapy

Background

Anti-cancer treatment can be fraught with cardiovascular complications, which is the most common cause of death among oncological survivors. Without appropriate cardiomonitoring during anti-cancer treatment, it becomes challenging to detect early signs of cardiovascular complications. In order to achieve higher survival rates, it is necessary to monitor oncological patients outpatiently after anti-cancer treatment administration. In this regard, we aim to evaluate the efficacy of single-lead ECG remote monitoring to detect cardiotoxicity in cancer patients with minimal cardiovascular diseases after the first cycle of polychemotherapy.

Materials and methods

The study included patients 162 patients over 18 years old with first diagnosed different types of solid tumors, planed for adjuvant (within 8 weeks after surgery) or neoadjuvant polychemotherapy. All patients were monitored, outpatiently, during 14-21 days (depending on the regimen of polychemotherapy) after polychemotherapy administration using single-lead ECG.

Results

QTc > 500 mc prolongation was detected in 8 patients (6.6 %), first-diagnosed arial fibrillation was detected in 11 patients (9 %) in period after chemotherapy administration. Moreover, left ventricular diastolic dysfunction using single-lead ECG after polychemotherapy was detected in 49 (40.1 %) patients with sensitivity 80 %, specificity 95 %, AUC 0.88 (95 % CI, 0.82-0.93).

Conclusions

The side effects of cancer treatment may cause life-threatening risks. Early identification of cardiotoxicity plays a vital role in the solution of this problem. Using portable devices to detect early cardiotoxicity is a simple, convenient and affordable screening method, that can be used for promptly observation of patients.

Accuracy of mobile 6-lead electrocardiogram device for assessment of QT interval: a prospective validation study

INTRODUCTION

Ambulatory assessment of the heart rate-corrected QT interval (QTc) can be of diagnostic value, for example in patients on QTc-prolonging medication. Repeating sequential 12-lead electrocardiograms (ECGs) to monitor the QTc is cumbersome, but mobile ECG (mECG) devices can potentially solve this problem. As the accuracy of single-lead mECG devices is reportedly variable, a multilead mECG device may be more accurate.

METHODS

This prospective dual-centre study included outpatients visiting our cardiology clinics for any indication. Participants underwent an mECG recording using a smartphone-enabled 6‑lead mECG device immediately before or immediately after a conventional 12-lead ECG recording. Multiple QTc values in both recordings were manually measured in leads I and II using the tangent method and subsequently compared.

RESULTS

In total, 234 subjects were included (mean ± standard deviation (SD) age: 57 ± 17 years; 58% males), of whom 133 (57%) had cardiac disease. QTc measurement in any lead was impossible due to artefacts in 16 mECGs (7%) and no 12-lead ECGs. Mean (± SD) QTc in lead II on the mECG and 12-lead ECG was 401 ± 30 and 406 ± 31 ms, respectively. Mean (± SD) absolute difference in QTc values between both modalities was 12 ± 9 ms (r = 0.856; p < 0.001). In 55% of the subjects, the absolute difference between QTc values was < 10 ms.

CONCLUSION

A 6-lead mECG allows for QTc assessment with good accuracy and can be used safely in ambulatory QTc monitoring. This may improve patient satisfaction and reduce healthcare costs.

The Relationship between Body Composition and ECG Ventricular Activity in Young Adults

This study aimed to determine the correlation between body composition (measured as weight, body mass index, and body fat percentage (BFP)) and electrocardiographic ventricular parameters (the QT and TQ intervals and the ratios between the electrical diastole and electrical systole (TQ/QT) and between the cardiac cycle and electrical diastole (RR/TQ), both for uncorrected and corrected intervals) in a sample of 50 healthy subjects (age interval 19-23 years, mean age 21.27 ± 1.41 years, 33 women and 17 men). Subjects' measurements were performed with a bioimpedancemetry body composition analyzer and a portable ECG monitor with six leads. Starting from the correlations obtained between the investigated continuous variables, we performed a standard linear regression analysis between the body composition parameters and the ECG ones. Our results revealed that some of our regression models are statistically significant (p < 0.001). Thus, a specific part of the variability of the dependent variables (ECG ventricular activity parameters for corrected QT intervals) is explained by the independent variable BFP. Therefore, body composition influences ventricular electrical activity in young adults, which implies a differentiated interpretation of the electrocardiogram in these situations.

Clinical Validation of Automated Corrected QT-Interval Measurements From a Single Lead Electrocardiogram Using a Novel Smartwatch

Introduction

The Withings Scanwatch (Withings SA, Issy les Moulineaux, France) offers automated analysis of the QTc. We aimed to compare automated QTc-measurements using a single lead ECG of a novel smartwatch (Withings Scanwatch, SW-ECG) with manual-measured QTc from a nearly simultaneously recorded 12-lead ECG.

Methods

We enrolled consecutive patients referred to a tertiary hospital for cardiac workup in a prospective, observational study. The QT-interval of the 12-lead ECG was manually interpreted by two blinded, independent cardiologists through the tangent-method. Bazett's formula was used to calculate QTc. Results were compared using the Bland-Altman method.

Results

A total of 317 patients (48% female, mean age 63 ± 17 years) were enrolled. HR-, QRS-, and QT-intervals were automatically calculated by the SW in 295 (93%), 249 (79%), and 177 patients (56%), respectively. Diagnostic accuracy of SW-ECG for detection of QTc-intervals ≥ 460 ms (women) and ≥ 440 ms (men) as quantified by the area under the curve was 0.91 and 0.89. The Bland-Altman analysis resulted in a bias of 6.6 ms [95% limit of agreement (LoA) -59 to 72 ms] comparing automated QTc-measurements (SW-ECG) with manual QTc-measurement (12-lead ECG). In 12 patients (6.9%) the difference between the two measurements was greater than the LoA.

Conclusion

In this clinical validation of a direct-to-consumer smartwatch we found fair to good agreement between automated-SW-ECG QTc-measurements and manual 12-lead-QTc measurements. The SW-ECG was able to automatically calculate QTc-intervals in one half of all assessed patients. Our work shows, that the automated algorithm of the SW-ECG needs improvement to be useful in a clinical setting.

Use of a smartphone electrocardiogram to diagnose arrhythmias during exercise in athletes: a case series

Background

While athletes are generally very fit, intense exercise can increase the risk of atrial fibrillation. Moreover, other arrhythmias such as atrial flutter or supraventricular tachycardia can cause distressing, exercise-related symptoms. Given symptoms are infrequent and may occur during intense exertion, traditional monitoring devices are often impractical to use during exercise. Smartphone electrocardiograms (ECGs) such as the Alivecor Kardia device may be the portable and reliable tool required to help identify arrhythmias in this challenging population. This case series highlights the use of such devices in aiding the diagnosis of arrhythmias in the setting of exercise-related symptoms in athletes.

Case summary

The six cases in this series included one elite non-endurance athlete, two elite cricketers, one amateur middle-distance runner, and two semi-elite ultra-endurance runners, with an age range of 16-48 years. An accurate diagnosis of an arrhythmia was obtained in five cases (atrial fibrillation/flutter and supraventricular tachycardias) using the smartphone ECG, which helped guide definitive treatment. No arrhythmia was identified in the final case despite using the device during multiple symptomatic events.

Discussion

The smartphone ECG was able to accurately detect arrhythmias and provide a diagnosis in cases where traditional monitoring had not. The utility of detecting no arrhythmia during symptoms in one case was also highlighted, providing the athlete with the confidence to continue exercising. This reassurance and confidence across all cases is perhaps the most valuable aspect of this device, where clinicians and athletes can be more certain of reaching a diagnosis and undertaking appropriate management.