Remote and wearable ECG devices with diagnostic abilities in adults: A state-of-the-science scoping review

The electrocardiogram (ECG) records the electrical activity in the heart in real time, providing an important opportunity to detecting various cardiac pathologies. The 12-lead ECG currently serves as the "standard" ECG acquisition technique for diagnostic purposes for many cardiac pathologies other than arrhythmias. However, the technical aspects of acquiring a 12-lead ECG are not easy. and its usage currently is restricted to trained medical personnel, which limits the scope of its usefulness. Remote and wearable ECG devices have attempted to bridge this gap by enabling patients to take their own ECG using a simplified method at the expense of a reduced number of leads, usually a single-lead ECG. In this review, we summarize the studies that investigated the use of remote ECG devices and their clinical utility in diagnosing cardiac pathologies. Eligible studies discussed Food and Drug Administration-cleared, commercially available devices that were validated in an adult population. We summarize technical logistics of signal quality and device reliability, dimensional and functional features, and diagnostic value. Our synthesis shows that reduced-set ECG wearables have huge potential for long-term monitoring, particularly if paired with real-time notification techniques. Such capabilities make them primarily useful for abnormal rhythm detection, and there is sufficient evidence that a remote ECG device can be superior to the traditional 12-lead ECG in diagnosing specific arrhythmias such as atrial fibrillation. However, this review identifies important challenges faced by this technology and highlights the limited availability of clinical research examining their usefulness.

Usefulness of Mobile Electrocardiographic Devices to Reduce Urgent Healthcare Visits

Mobile electrocardiogram (mECG) devices are being used increasingly, supplying recordings to providers and providing automatic rhythm interpretation. Given the intermittent nature of certain cardiac arrhythmias, mECGs allow instant access to a recording device. In the current COVID-19 pandemic, efforts to limit in-person patient interactions and avoid overwhelming emergency and inpatient services would add value. Our goal was to evaluate whether a mECG device would reduce healthcare utilization overall, particularly those of urgent nature. We identified a cohort of KardiaMobile (AliveCor, USA) mECG users and compared their healthcare utilization 1 year prior to obtaining the device and 1 year after. One hundred and twenty-eight patients were studied (mean age 64, 47% female). Mean duration of follow-up pre-intervention was 9.8 months. One hundred and twenty-three of 128 individuals completed post-intervention follow-up. Patients were less likely to have cardiac monitors ordered (30 vs 6; p <0.01), outpatient office visits (525 vs 382; p <0.01), cardiac-specific ED visits (51 vs 30; p <0.01), arrhythmia related ED visits (45 vs 20; p <0.01), and unplanned arrhythmia admissions (34 vs 11; p <0.01) in the year after obtaining a KardiaMobile device compared to the year prior to obtaining the device. Mobile technology is available for heart rhythm monitoring and can give feedback to the user. This study showed a reduction of in-person, healthcare utilization with mECG device use. In conclusion, this strategy would be expected to decrease the risk of exposure to patients and providers and would avoid overwhelming emergency and inpatient services.

Expanding a single‑lead mobile electrocardiographic device to multiple‑lead recordings improves diagnostic accuracy and confidence

BACKGROUND

Mobile electrocardiographic (mECG) devices that record ECG lead I have been used to detect atrial fibrillation. Other arrhythmias may not be readily diagnosed with one lead. Obtaining multi‑lead tracings from an mECG (MLmECG) to simulate a 12‑lead ECG may lead to more accurate diagnoses.

METHODS

We developed a method to generate multi‑lead ECGs using a mECG device by attaching it with alligator clips connected to an insulated copper wire to adhesive electrodes on the patient's limbs and torso according to standard lead configurations. Different rhythm and conduction abnormalities from a sample of inpatients were collected. Arrhythmias were recorded in three ways (single lead, MLmECG, and standard 12‑lead) and grouped by category. Recordings were sent to cardiology fellows in the form of a multiple choice survey. Participants were asked for their diagnosis and confidence in their decision.

RESULTS

Survey response rate was 100%. Single‑lead, MLmECG, and 12‑lead yielded 48.2%, 81.6%, and 88.6% of agreement with the correct diagnosis, respectively (single‑lead vs. MLmECG or 12‑lead; p < 0.01). Overall mean confidence scores were 3.34, 4.35, and 4.53 out of 5, for single‑lead, MLmECG, and 12‑lead ECG, respectively (single‑lead vs. MLmECG or 12‑lead; p < 0.01, MLmECG vs. 12‑lead; p = 0.09).

CONCLUSION

The diagnostic accuracy of MLmECGs were similar to that of a standard 12‑lead ECG. Fellows' confidence in their diagnosis were similar between MLmECG or 12‑lead ECG, and higher with both modalities compared to a single‑lead tracing. The ability to recreate, as fully as possible, a standard 12‑lead ECG is a reasonable goal for mobile technology.

Initial Experience in Monitoring QT Intervals Using a Six-lead Contactless Mobile Electrocardiogram in an Inpatient Setting

Mobile electrocardiograms (ECGs) (mECGs) using smartphone applications are an emerging technology. In the coronavirus disease 2019 (COVID-19) era, minimizing patient contact has gained increasing importance. Additionally, increased QT/corrected QT (QTc) monitoring has concurrently been required. The KardiaMobile 6L ECG device, cleared by the United States Food and Drug Administration (FDA) for recording ECGs, along with the KardiaStation tablet application is a platform (AliveCor, Mountain View, CA, USA) that addresses these two issues. A team of residents, fellows, hospitalists, and cardiologists identified inpatients in need of QT/QTc interval monitoring to pilot the adoption of a system composed of a KardiaMobile 6L ECG device with the accompanying KardiaStation tablet application. Concurrent standard ECGs provided validation. Adoption and performance issues were recorded. Four patients agreed to participate in QT/QTc interval monitoring, three of whom were positive for severe acute respiratory syndrome coronavirus 2 viral infection. After basic instructions were given to the patients and their clinical nurses, all patients recorded mECGs successfully. Patients were able to record their own mECG tracings at least once without any assistance. The 12-lead ECGs and mECGs each showed the correct rhythm, and the measured QTc intervals on each modality were consistently acceptable (< 500 ms). Contactless ECGs were successfully uploaded to KardiaStation for QT/QTc interval measurement and archiving. In this study, we showed that an FDA-cleared product, KardiaMobile 6L, has the ability to provide high-quality contactless ECGs for reliable QT/QTc interval measurements. Hospitalized patients were able to perform recordings when requested after receiving simple instructions at the time of first use. This technology has applications during the COVID-19 pandemic and beyond.