The efficacy of detecting arrhythmia is higher with 7‐day continuous electrocardiographic patch monitoring than with 24‐h Holter monitoring

Abstract Background Detecting high‐risk arrhythmia is important in diagnosing patients with palpitations. We compared the diagnostic accuracies of 7‐day patch‐type electrocardiographic (ECG) monitoring and 24‐h Holter monitoring for detecting significant arrhythmias in patients with palpitations. Methods This was a single‐center prospective trial with 58 participants who presented with palpitations, chest pain or syncope. Outcomes were defined as the detection of any one of six arrhythmias, including supraventricular tachycardia (SVT), atrial fibrillation or atrial flutter lasting more than 30 s, pauses of more than 3 s, high‐degree atrioventricular block, ventricular tachycardia (VT) >3 beats, or polymorphic VT/ventricular fibrillation. The McNemar test for paired proportions was used to compare arrhythmia detection rates. Results The overall arrhythmia detection rate was higher with 7‐day ECG patch monitoring than with 24‐h Holter monitoring (34.5% vs. 19.0%, p = .008). Compared with the use of 24‐h Holter monitors, the use of 7‐day ECG patch monitors was associated with higher detection of SVT (29.3% vs. 13.8%, p = .042). No serious adverse skin reactions were reported among the ECG patch‐monitored participants. Conclusions The results suggest that a 7‐day patch‐type continuous ECG monitor is more effective for the detection of supraventricular tachycardia than is a 24‐h Holter monitor. However, the clinical significance of device detected arrhythmia should be consolidated.


| INTRODUC TI ON
Palpitations are one of the most common symptoms in patients who present to primary care clinicians and cardiologists. 1 Although the causes are usually benign, palpitations occasionally manifest as potentially life-threatening arrhythmias. Thus, an appropriate evaluation of palpitations is required.
Cardiac arrhythmias, including the development of new arrhythmias or significant changes in the rate of previously stable arrhythmias, are common causes of palpitations. Conventional Holter monitoring plays a significant role in the diagnosis of arrhythmias when evaluating palpitations. 2 However, it has the drawbacks of low diagnostic yield in detecting paroxysmal arrhythmias, burdensome wires that interfere with daily activities, and the inability of some patients to activate the event recorders when symptoms occur. 3,4 Recently, several newer generation electrocardiography (ECG) monitoring devices with advanced technologies have shown more advantages over the conventional 24-h Holter monitoring devices in terms of convenience, efficient energy use, longer duration of monitoring, wireless data transfer, and no interruption of daily activities. 5 Researchers developed a deep neural network to diagnose cardiac arrhythmia, demonstrating its superior ability to classify the 12 rhythm classes compared with interpretations by individual cardiologists. 6 Detection rates of cardiac arrhythmias for extended durations with fully automated and highly accurate systems were studied, and the results suggested that they could aid cardiologists in the accurate detection of arrhythmias. 7,8 The MEMO patch version 1 (HUINNO Co., Ltd.) is the first Korean Food and Drug Administration (KFDA)-approved, single-lead, lightweight, 7-day ambulatory ECG adhesive patch monitor ( Figure 1).
Soon after the release of version 1, version 2 was developed, tested, and approved for 14-days of ambulatory ECG monitoring by KFDA.
The device has no wires and can be re-attached every day with disposable 3M adhesives; therefore, it does not interfere with the patient's daily activities.
We compared the diagnostic accuracies of 7-day adhesive patch monitoring (the MEMO patch version 1) and 24-  The MEMO patch can store ECG data for up to 14 days in its internal storage. The stored ECG data can be extracted by connecting the device to a dedicated cradle with software for data download. The extracted ECG data are automatically uploaded to a cloud-based system through the software, and the initial analysis by the artificial neural network, constructed and trained by HUINNO, is automatically triggered. The network used in this study for the seven-class ECG classification was based on the 152-layer convolutional neural network architecture with skip connections, which is called a residual network, and squeeze and excitation blocks. 9 The ECG recording was initially analyzed using F I G U R E 1 Overview of where the concomitant Holter electrocardiography and MEMO® patch is worn on the torso. deep learning-based automated algorithms, 9 however, technicians manually double checked and reviewed the artificial intelligence (AI) diagnosis and if needed, revised the diagnosis after it was confirmed by cardiologists. The correction rate of the AI driven diagnosis, except for the ECG noise, included a total of three diagnoses (3/51, 5.9%), specifically, two for second-degree (Mobitz type I) atrioventricular block (AVB) and one for intermittent 2:1 AVB.

| Study protocol and outcomes
The network was trained by cardiologist-reviewed 18 000 lead II ECG data recordings acquired from the Seoul National University Bundang Hospital.
The Holter and MEMO data were subjected to a technical review for report generation and quality assurance. This report was then uploaded to a secure website for independent review by two investigators (J.H.L. and Y.C.). If there were any discrepancies in the interpretation of the ECG signals, then the sets of signals were sent to a senior cardiologist who decided on the final classification Outcomes were defined as the detection of any one of the six arrhythmias: (1) supraventricular tachycardia (>3 beats, not including atrial fibrillation or flutter), (2) atrial fibrillation or atrial flutter lasting more than 30 s, (3) pause of more than 3 s, (4) AVB (second-degree AVB Mobitz type II or third-degree AVB), (5) ventricular tachycardia >3 beats, or (6) polymorphic ventricular tachycardia or ventricular fibrillation.

| Statistics
The MEMO Patch and the Holter device were used simultaneously on the same patients during the first 24 h. This study compared the detection rates of arrhythmia events between the MEMO patch and Holter device over the total monitoring time of each device.
Continuous variables are presented as means and standard deviations, and categorical variables are shown as numbers with percentages. The McNemar test for paired proportions was used to compare the detection rate for arrhythmias between the Holter and MEMO patch monitors.

| Estimation of sample size calculation
A previous study showed that the adhesive patch monitor detected 36 more arrhythmia events than did the Holter monitor, while the Holter monitor detected one event undetected by the adhesive patch monitor. 10 Another study found that 202 atrial fibrillation or flutter episodes were detected in six patients with 14-day ECG patches, while only one atrial fibrillation episode was detected in a patient with a 24-h Holter monitor. 11 Since our study aimed to compare 7-day ECG patch monitors with 24-h Holter monitors, we assumed that the odds ratio of detecting arrhythmias could be six times higher with the MEMO patch than with the 24-h Holter monitor. A sample size of at least 57 after attrition achieved 90% power for a two-tailed McNemar test with a type 1 error of 0.05 (G*Power software version 3.1.9.4). 12

| RE SULTS
Of the 70 participants screened, 60 were enrolled; 2 enrolled patients were lost to follow-up. A total of 58 participants with data available from both the Holter and MEMO patch groups were included in the final analysis. The baseline characteristics of the patients are presented in Table 1. The mean age was 50.5 years and 57% (33/58) were women. Hypertension (15/58, 26%) and dyslipidemia (14/58, 24%) were common underlying medical conditions.

| Detection rate for significant arrhythmias
The detection rates of significant arrhythmias, defined as the outcomes, are summarized in Table 2. The cumulative detection rates of MEMO patches on days 1 and 7 were 19.0% (11/58) and 34.5% The detection rate for total significant arrhythmias was higher with MEMO patches (34.5% vs. 19.0%, p = .008), as shown in Table 2.

Characteristics
Age (

| Detection of all arrhythmias
A total of 51 arrhythmias were detected by MEMO patch monitoring and 22 arrhythmias were detected by Holter monitoring, as shown in

| CON CLUS ION
In this single-center prospective trial, 7-day patch-type continuous ECG monitoring was more effective in detecting supraventricular tachycardia than was 24-h Holter monitoring. However, detecting other types of significant arrhythmias with ECG patch monitoring might require a longer duration of more than 7 days. Further studies on the efficacy of detecting specific arrhythmias in certain populations are required. In addition, studying the comparative effectiveness will help choose the most appropriate options for patients in terms of monitoring periods, costs, convenience, and limitations among various types of ECG devices.

CO N FLI C T O F I NTER E S T S TATEM ENT
JuYK is employed part-time at HUINNO Co., Ltd Seoul, Korea. YG, SJ, DK, MGS, JYY, and JK are currently employed at HUINNO Co., Ltd Seoul, Korea. The rest of the authors declare that they have no conflicts of interest.

DATA AVA I L A B I L I T Y S TAT E M E N T
The data that support the findings of this study are available from the corresponding author (Il-Young Oh) upon reasonable request.

E TH I C S A PPROVA L S TATEM ENT
The Institutional Review Board of Seoul National University Bundang Hospital approved the protocol (approval No: E-1901-516-001).