Pilot evaluation of an integrated monitor-adhesive patch for long-term cardiac arrhythmia detection in India

Review of the Requirements for a Wearable, Low-Cost External Cardiac Loop Recorder with WBAN in Resource-Constrained Settings

Cardiovascular disease (CVD) has become the most serious health concern in India and globally. The cost of treatment for CVD is very high and in a country like India, where most of the population belongs to rural area, affording treatment is not possible. Diagnosis and treatment are further hampered due to shortage of medical expertise as well as the unavailability of the wearable device. This makes the condition worst in rural areas. As a result of delay in diagnosis, patients do not receive appropriate treatment on time, thus risking lives. Hence, early detection of physiological abnormalities in patients is the best solution to avoid sudden death. In India, the majority of ECG diagnosis is done using a standard ECG machine or Holter monitor, which are not adequate to detect transient or infrequent arrhythmia as the window of detection is 30 s or up to 48 h. So, for arrhythmia diagnosis or syncope and palpitation, external cardiac loop recorder (ECLR) is preferred. ECLR is a monitoring device which records cardiac activities and detects infrequent arrhythmias with syncope and palpitation of a subject for longer period continuously. Due to recent improvements in technology, such as flexible electronics and wireless body area network (WBAN), wearable medical devices are progressively assisting people to monitor their health status while doing their day-to-day activities and furnishing more information to clinicians for early diagnosis and treatment. Flexible electronics allows to develop an electronic circuit on a flexible substrate hence making the device bendable and stretchable. WBAN is a wireless communication between different nodes like sensors and processors that are located at different points on the body. By incorporating technologies such as miniaturization of electronics, making flexible electronics and WBAN concept in ECLR, the device can be made wearable so as to not interfere with the patient's day-to-day activities. This review paper discusses the limitations of existing standard ECG machines as well as how to make the existing ECLR devices more robust, more advanced, more comfortable and also affordable.

Identifying high risk patients post myocardial infarction with reduced left ventricular function using loop recorders INSPIRE-ELR clinical study

Aims

Sudden cardiac death (SCD) continues to be a devastating complication amongst survivors of myocardial infarction (MI). Mortality is high in the initial months after MI. The aims of the INSPIRE-ELR study were to assess the proportion of patients with significant arrhythmias early after MI and the association with mortality during 12 months of follow-up.

Methods

The study included 249 patients within 14 days after MI with left ventricular ejection fraction (LVEF) ≤35% at discharge in 11 hospitals in India. Patients received a wearable external loop recorder (ELR) 5 ± 3 days after MI to monitor arrhythmias for 7 days.

Results

Patients were predominantly male (86%) with a mean age of 56 ± 12 years. In 82%, reperfusion had been done and all received standard of care cardiovascular medications at discharge. LVEF was 32.2 ± 3.9%, measured 5.1 ± 3.0 days after MI. Of the 233 patients who completed monitoring (7.1 ± 1.5 days), 81 (35%) experienced significant arrhythmias, including Ventricular Tachycardia/Fibrillation (VT/VF): 10 (4.3%); frequent Premature Ventricular Contractions (PVCs): 65 (28%); Atrial Fibrillation (AF): 8 (3.4%); chronic atrial flutter: 4 (1.7%); 2nd or 3rd degree Atrioventricular (AV) block: 4 (1.7%); and symptomatic bradycardia: 8 (3.4%). In total, 26 patients died. Mortality was higher in patients with clinically significant arrhythmia (at 12 months: 23.6% vs 4.8% with 19 vs 7 deaths, hazard ratio (HR) = 5.5, 95% confidence interval (CI) 2.3 to 13.0, p < 0.0001). Excluding 7 deaths during ELR monitoring, HR = 4.5, p < 0.001.

Conclusion

ELR applied in patients with acute MI and LV dysfunction at the time of discharge identifies patients with high mortality risk.

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External Loop Recorder applied in patients with acute MI and LV dysfunction showed a high incidence of clinically significant arrhythmias.

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Significant arrhythmias within 14 days of hospital discharge were associated with 5 times higher mortality at one year.

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A simple ELR-based risk score was an independent predictor of mortality.

Accuracy of mHealth Devices for Atrial Fibrillation Screening: Systematic Review

BACKGROUND

Mobile health (mHealth) devices can be used for the diagnosis of atrial fibrillation. Early diagnosis allows better treatment and prevention of secondary diseases like stroke. Although there are many different mHealth devices to screen for atrial fibrillation, their accuracy varies due to different technological approaches.

OBJECTIVE

We aimed to systematically review available studies that assessed the accuracy of mHealth devices in screening for atrial fibrillation. The goal of this review was to provide a comprehensive overview of available technologies, specific characteristics, and accuracy of all relevant studies.

METHODS

PubMed and Web of Science databases were searched from January 2014 until January 2019. Our systematic review was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analyses. We restricted the search by year of publication, language, noninvasive methods, and focus on diagnosis of atrial fibrillation. Articles not including information about the accuracy of devices were excluded.

RESULTS

We found 467 relevant studies. After removing duplicates and excluding ineligible records, 22 studies were included. The accuracy of mHealth devices varied among different technologies, their application settings, and study populations. We described and summarized the eligible studies.

CONCLUSIONS

Our systematic review identifies different technologies for screening for atrial fibrillation with mHealth devices. A specific technology's suitability depends on the underlying form of atrial fibrillation to be diagnosed. With the suitable use of mHealth, early diagnosis and treatment of atrial fibrillation are possible. Successful application of mHealth technologies could contribute to significantly reducing the cost of illness of atrial fibrillation.

Wireless body sensor for electrocardiographic monitoring in dogs and cats

OBJECTIVES

To evaluate the diagnostic utility of electrocardiogram data obtained by a wireless sensor from 36 dogs and four cats with suspected arrhythmias caused by cardiac or systemic diseases.

MATERIALS AND METHODS

Wireless electrocardiographic recordings were obtained via two precordial electrodes attached to an electrocardiogram sensor connected to a smart device via low-power Bluetooth technology. Cardiac rate, rhythm and duration of P-QRS-T waves were evaluated with VisECG® software. Fifteen- to 30-minute wireless recordings were compared to standard electrocardiograms. Furthermore, the wireless sensor was used in 10 dogs and four cats for 24-hour continuous electrocardiogram monitoring at home.

RESULTS

When compared to standard electrocardiogram, equivalent results were obtained for heart rate and duration of different waves. Due to the longer recording time, more arrhythmias were diagnosed with the wireless device in 50% (15 of 30) of animals with arrhythmias. Satisfactory recordings were obtained when the dogs were resting, standing or walking but interpretation of the wireless electrocardiogram signal was not possible during strenuous physical activity.

CLINICAL SIGNIFICANCE

Wireless electrocardiographic monitoring is a reliable and accurate method for identification of heart rate, arrhythmia and duration of electrocardiogram waves. A higher diagnostic yield of arrhythmias was documented with the wireless sensor due to prolonged monitoring. The device offers a good option for the long-term monitoring of canine and feline cardiac rhythm.

Role of hospitalists in the diagnosis of atrial fibrillation for the management of cryptogenic stroke patients

Cryptogenic strokes are responsible for significant morbidity and mortality. Identifying the underlying cause of cryptogenic stroke is imperative for appropriate short and long-term management of these patients. In particular, detecting atrial fibrillation in cryptogenic stroke patients may shed insight into the cause of the index stroke, but is also important to identify an important cause of secondary stroke. There is accumulating evidence indicating that monitoring for durations beyond the guideline recommended 30 day-period results in greater atrial fibrillation yield. This article reviews current guidelines and practices for the diagnosis of cryptogenic stroke, as well as outpatient cardiac monitoring options available, and focuses on the role that hospitalists have to play in the care of these patients.

Diagnostic yield of patch ambulatory electrocardiogram monitoring in children (from a national registry)

The diagnostic yield of continuous electrocardiographic (ECG) monitoring in children for periods longer than a Holter monitor is unclear. The aim of this study was to characterize diagnostic yield, arrhythmia type, and time to first arrhythmia using a clinical repository of national ambulatory ECG data in children. A cross-sectional study was performed in 3,209 consecutive children receiving a 14-day adhesive patch monitor (Zio Patch) for clinical indications from January 2011 to December 2013. Of the 3,209 children (56% female, mean age 12.5 ± 4.4 years, range 1 month to 17 years), 390 had arrhythmias detected, making the diagnostic yield 12.2%. Of these, 137 patients (4.3%) had arrhythmias deemed clinically significant to warrant urgent physician notification. The most frequent indications for monitoring were palpitations (n = 1,138 [35.5%]), syncope (n = 450 [14.0%]), unspecified tachycardia (n = 291 [9.1%]), supraventricular tachycardia (n = 264 [8.2%]), and chest pain (n = 261 [8.1%]). Arrhythmias were detected in 10.0% of patients with palpitations, 6.7% of patients with syncope, 14.8% of patients with tachycardia, 22.7% of patients with supraventricular tachycardia, and 6.5% of patients with chest pain. The mean times to first detected and first symptom-triggered arrhythmias were 2.7 ± 3.0 and 3.3 ± 3.3 days, respectively. Forty-four percent of first detected arrhythmias and 50.4% of the first symptom-triggered arrhythmias occurred beyond 48 hours of monitoring. In conclusion, the diagnostic yield of continuous ECG patch monitoring in children was substantial beyond 48 hours and should be considered in children who are candidates for longer term ECG monitoring.

Patient experience with a novel patch-like external loop recorder for cardiac arrhythmia detection in India

Cardiovascular disease (CVD) is reaching pandemic proportions in India. The effects of CVD are disastrous for the Indian economy as the disease strikes in the prime working ages of the labor force. The great need for therapeutic and diagnostic options combined with pressure on cost containment place emphasis on the development of low cost, credible, point of care diagnostic tools to pinpoint issues in cardiac health for the Indian consumer. A previous study of 125 patients in India examined a novel external loop recorder (ELR) for ambulatory ECG monitoring with high yield and compliance. The current study probes the patient experience, inclusive of patient comfort, ease of use, clarity of the diagnostic report, and value of the ELR. The analysis shows that 85% found this ELR comfortable to wear and deploy, 77% responded with no challenges with the use of this ELR, 60% mentioned they were inclined to seek treatment after this ELR was deployed, and 60% found good value in the device. The results indicate that this particular ELR is a high performing device with excellent patient satisfaction, indicating that the device is a suitable tool for diagnosis of cardiac arrhythmia in India.