European Journal of Cardiovascular Medicine

The prevalence of arrhythmias is increasing as life expectancy improves with advances in healthcare. A 12-lead electrocardiogram is usually the first investigation for patients presenting with paroxysmal palpitations or syncope. However, a 12-lead ECG often does not capture the diagnosis. Although 24-hour Holter monitoring has been routinely used for suspected paroxysmal arrhythmias, it can be cumbersome, and its sensitivity for detecting intermittent arrhythmias is limited. Several ambulatory ECG devices are available, ranging from event monitors to implantable loop recorders; however, there is no standard duration or device for evaluating paroxysmal arrhythmias, and there is no consensus on the ideal device or monitoring period. Therefore, we conducted a prospective study at our institute using a 3-day (and, in a separate cohort, 7-day) externally applied WebCardio patch monitor in patients with suspected paroxysmal arrhythmias to evaluate the safety, efficacy, and diagnostic yield of arrhythmia detection.

Objective:

To assess the utility of a web-based external patch monitor for detecting arrhythmia burden in patients with suspected paroxysmal arrhythmias.

In all patients, the Webcardio patch was applied to the left upper chest after skin preparation. The Webcardio patch is a single-use, two-channel ECG patch that weighs approximately 28 grams and measures 10 cm × 8 cm. It can be applied easily to the chest wall and is comfortable for patients. The patch was applied after obtaining consent, and patients were instructed on how to trigger the device during symptoms. The Webcardio patch was paired with a mobile device containing the WebCardio app, downloaded from the Google Play Store or Apple store. Relevant patient details were entered into the WebCardio app at the start of the procedure, and patients were instructed to trigger the device during symptoms. After the initial setup, ECG signal quality was confirmed using the WebCardio system. Once paired, the Webcardio patch continuously and wirelessly transmitted ECG signals to the mobile device and then to the remote server until disconnection or up to 3 days (3-day cohort) or up to 7 days (7-day cohort). All patients were encouraged to keep the mobile device with them throughout monitoring. The ambulatory ECG was analysed using proprietary software by a qualified Holter technician at the remote centre, and a report was generated and sent to the hospital by email. The investigating cardiologists reviewed the complete ambulatory ECG recording, arrhythmic events, and report after logging in to the WebCardio site. Detection of at least one of the following arrhythmias was assessed: atrial fibrillation (AF), atrioventricular (AV) block, sinus pause of more than 2.5 seconds, supraventricular tachycardia (SVT), premature ventricular complexes (PVCs), ventricular tachycardia (VT), and ventricular fibrillation (VF). Standard definitions of arrhythmia were used for event review.

In addition to the 3-day cohort, a separate cohort of 29 patients underwent monitoring with the 7-day WebCardio patch at PSG Hospital during the same duration. The same application, pairing, data transmission, and analysis procedures were followed. Because the monitoring durations differed, the 3-day and 7-day cohorts were analysed separately, and the data were not pooled. For the 7-day cohort, results are reported separately.

Table A Operational definitions of Arrhythmias included in the study

ᵃThresholds were confirmed from individual monitoring reports

Clinical characteristics of the study population:

A total of 1076 consecutive patients who presented to the outpatient department with symptoms suggestive of paroxysmal arrhythmias were enrolled. The mean age of the study population was 55.86 ± 19.60 years. Most patients were older than 60 years (553; 54.16%), followed by those aged 40–59 years (296; 28.99%) and 18–39 years (172; 16.85%). There was a male predominance, with 639 male patients (59.39%) and 437 female patients (40.61%).In the separate 7-day cohort (n = 29; mean age 66.41 ± 14.71 years; 16 male [55.17%] and 13 females [44.83%]).  The clinical characteristics of the study population are summarized in Table 1 and Table 4 respectively.

Arrhythmias detected:

The recordings were of good quality with very little artifact, as shown in Fig. 2. Analysis of WebCardio patch recordings identified a total of 1076procedures,  As shown in Table 2, supraventricular tachycardia (SVT) was the most common arrhythmia detected (472 events), followed by ventricular tachycardia (VT; 191 events), second-degree atrioventricular block (AVB; 109 events), pauses (100 events), atrial fibrillation (AF; 89 events), complete heart block (CHB; 37 events), and >2:1 AVB (4 events). A substantial proportion of arrhythmias were first detected after 24 hours and would therefore likely have been missed by a routine 24-hour Holter recording. As shown in Table 3, 30.95% of AF, 35.17% of SVT, 40.84% of pauses, and 44.0% of VT events were detected after the first day. Several of these findings have direct clinical relevance: CHB, higher-grade AV block, and pauses are conventionally evaluated for pacing, VT warrants assessment for underlying structural heart disease and arrhythmic risk, and AF informs stroke-prevention decisions. These values are event counts; the number of individual patients affected by each arrhythmia was not derived.

Table 1. Clinical characteristics of the study population

Note: Values are presented as mean ± standard deviation or n (%). The age-group percentages are calculated using the number of patients with available age-group data as the denominator.

Table 2. Distribution of arrhythmias detected during WebCardio patch monitoring

         Note: Values indicate the number of arrhythmic events detected. AFib, atrial fibrillation; AVB, atrioventricular block; CHB, complete heart block; SVT, supraventricular tachycardia; VT, ventricular tachycardia.

Table 3. Proportion of arrhythmic events detected after the first 24 hours of monitoring

      Note: Values represent the percentage of each arrhythmia type first detected after 24 hours of continuous WebCardio patch monitoring. AF, atrial fibrillation; SVT, supraventricular tachycardia; VT, ventricular tachycardia.

7-day monitoring cohort: A separate cohort of 29 patients underwent 7-day WebCardio patch monitoring and is reported independently of the 3-day cohort. The mean age was 66.41 ± 14.71 years (range 17–87 years), and most patients were aged 60 years or older (22; 78.57%). There were 16 male patients (55.17%) and 13 female patients (44.83%) (Table 4). The most frequent indications were presyncope (6; 20.69%), stroke (4; 13.79%), syncope (3; 10.34%), and chest pain (3; 10.34%). At least one arrhythmia was detected in 25 of 29 patients (86.21%), while no arrhythmia was detected in 4 patients (13.79%). As shown in Table 5, SVT was the most common finding (19 patients; 65.52%), followed by AV block (9; 31.03%), pauses (9; 31.03%), VT (4; 13.79%), junctional beats (3; 10.34%), and AF (1; 3.45%). Among patients monitored for syncope (n = 3), pauses and AV block were each recorded in 2; among those with presyncope (n = 6), pauses and AV block were each recorded in 2 and VT in 1; and VT was recorded in 1 of 2 patients with palpitation. These findings provide the relevance of monitoring for longer duration to detect those clinically significant arrhythmias which would have been missed by traditional holter.

Table 4. Clinical characteristics of the 7-day monitoring cohort

Note: Values are presented as mean ± standard deviation or n (%). Age-group percentages are calculated using the 29 patients with available age-group data

Table 5. Arrhythmias detected during 7-day WebCardio patch monitoring (patients, N = 29)

Note patients could have more than one arrhythmia type, so categories overlap. Percentages use N = 29. AF, atrial fibrillation; AVB, atrioventricular block; SVT, supraventricular tachycardia; VT, ventricular tachycardia.

Figure 4 First detection all arrhythmias Age wise distribution of detected arrythmias and first day detection (3-Day Monitoring)

Several devices are available in the market today for evaluation of paroxysmal arrhythmias in ambulatory patients1. Traditionally, Holter recording is done for 24 hours. Continuous ECG recording is useful, but it is cumbersome because multiple leads are attached to the patient, and it is often affected by artifacts and reduced patient compliance. Event recorders are another type of device available, but they must be worn continuously and do not provide continuous ECG data2,3. The patient must trigger the device during the event, which may not always be possible, and these devices may not capture silent asymptomatic arrhythmias. Loop recorders also provide only a fixed length of recording data before and after a predefined arrhythmia2,3. Mobile cardiac telemetry devices can record continuous ECG for 30 days, but they are costly and bulkier, limiting their use. Implantable loop recorders are invasive and costly and therefore cannot be used frequently. External patch monitors like Zio Patch are available in the market and are easy to use and wearable without disconnection for prolonged periods4, but they are not widely available in our setting. A similar device, the WebCardio patch monitoring system, is waterproof and easily attached to the chest wall without dermal irritation5,6. It can be removed during bathing and reattached by the patient during the monitoring period and can be used for monitoring up to 7 days. In our study, we evaluated the effectiveness of patch monitoring in detecting arrhythmias in patients with infrequent paroxysmal arrhythmic symptoms. WebCardio is a cloud-based cardiac rhythm monitoring device that can be easily applied to the patient’s chest wall, with good compliance and acceptance for prolonged monitoring. In this study, 1076 arrhythmic events were recorded, with SVT being the most common event (472), followed by VT (191), second-degree AV block (109), pauses (100), AFib (89), complete heart block (37), and >2:1 AV block (4). Notably, a considerable proportion of arrhythmias were first detected after the initial 24 hours: AF 30.95%, SVT 35.17%, pauses 40.84%, and VT 44.0%. These findings suggest that traditional 24-hour Holter recording may miss a clinically meaningful proportion of arrhythmias, supporting the potential role of convenient, wearable patch monitoring in the evaluation of paroxysmal arrhythmias, although a direct comparison with Holter monitoring was not performed in this study.Long-term, continuous, uninterrupted cardiac recording may improve arrhythmia detection compared with current standard recording technologies. Continuous ECG recording for 24–48 hours with multi-lead Holter monitors is commonly used as an initial option for screening and detecting cardiac arrhythmias7,8. Although multi-lead ECG monitors may offer advantages over single-lead monitors in selected situations, such as distinguishing ventricular tachycardia from aberrant atrial rhythms, limitations related to patient comfort, adherence, and signal quality may reduce arrhythmia detection within a 1–2-day recording window and may require repeat monitoring. Other longer-duration external monitoring technologies, such as external loop recorders and mobile cardiovascular telemetry, may improve detection compared with Holter monitoring because of longer recording periods. However, their use may be limited by the need to recharge or replace batteries, replace lead-wire patches, or remove the device during activities such as showering or physical activity9. Finally, although implantable cardiac monitors have shown promise for long-term arrhythmia detection, their invasive nature and high cost may limit widespread use and make them unsuitable as a first-line monitoring option for many patients.

In the separate 7-day cohort of 29 patients (mean age 66.41 ± 14.71 years), at least one arrhythmia was detected in 86.21%, most frequently SVT (65.52%), AV block (31.03%), pauses (31.03%), and VT (13.79%). These findings indicate that prolonged patch monitoring can capture a broad spectrum of arrhythmias, including potentially clinically significant bradyarrhythmias and ventricular tachycardia which would be missed by traditional holter. The 3-day and 7-day cohorts were analysed independently and were not pooled or directly compared. in addition,the 7-day cohort was small, so larger comparative studies are needed to define the incremental yield of 7-day over 3-day monitoring.

Clinical implications: The arrhythmias identified through extended patch monitoring have direct management relevance and illustrate the clinical utility of prolonged rhythm surveillance. Documentation of pauses, higher-grade atrioventricular block, or complete heart block in patients with syncope or presyncope can establish a bradyarrhythmic cause of symptoms and guide appropriate evaluation for permanent pacing. Detection of ventricular tachycardia enables risk stratification and may prompt assessment for underlying structural heart disease, initiation or adjustment of antiarrhythmic therapy, or referral for electrophysiological evaluation.

Prolonged continuous patch-based ECG monitoring with the WebCardio system demonstrated clinical utility by detecting a substantial burden of clinically actionable arrhythmias, including SVT, AV block, pauses, VT, and AF. The finding that many events were first identified after 24 hours indicates that shorter recordings may under-detect intermittent arrhythmias, while the high arrhythmia-detection rate in the 7-day cohort further supports the value of extended monitoring. Detection of conduction disease, pauses, VT, and AF provides clinically meaningful information that can inform pacing evaluation, anticoagulation, antiarrhythmic therapy, and electrophysiological referral. Although downstream management decisions and outcomes were not assessed, these results suggest that WebCardio patch monitoring can provide actionable diagnostic information in patients with suspected paroxysmal arrhythmias; larger prospective multicentre studies are warranted to confirm these findings and define the incremental yield of 7-day over 3-day monitoring.

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