Patient Directed Recording of a Bipolar Three-Lead Electrocardiogram using a Smartwatch with ECG Function
December 11th, 2019
We describe a protocol for the patient-directed registration of a three lead bipolar electrocardiogram by a smartwatch that functions identically to the Einthoven leads from standard electrocardiograms. This enables patients to record electrocardiograms on their own immediately after the onset of symptoms.
This protocol enables subjects owning a smartwatch with ECG function to record three bipolar signal lead ECGs comparable to Einthoven leads one to three from a standard ECG. This technique may help to detect cardiac arrhythmias or myocardial ischemia. Subjects could help a doctor identify ECG abnormalities immediately after onset of symptoms.
This method can principally be applied to all bipolar ECG recording devices and smartwatches with ECG function, except for the protocol for sending PDF to the doctor, which is specific to the device app. It is important that the subject is able to generate a good skin contact, especially during recording of leads two and three. It may be difficult to record Einthoven leads two and three because the watch has to be placed in the lower abdominal of the individual.
Therefore a resting position is mandatory. Demonstrating the procedure will be Sven Kaese, a colleague from our department. To record a standard ECG, use a common ECG device and adjust the paper running speed to 50 millimeters per second.
Perform the recording after a five minute resting period in a supine position. Place the right and left arm electrodes near the shoulders and the right and left leg electrodes near the ankles. Then place the V1 and V2 electrodes in the fourth intercostal space at the right and left parasternal lines respectively.
Place the V4 electrode in the fifth intercostal space at the midclavicular line and the V3 electrode between the V2 and V4.Then place the V5 electrode in the fifth intercostal space at the anterior axillary line and the V6 electrode at the mid axillary line. Once all electrodes are in place, record a standard 12 lead ECG with the ECG device. Record the smartwatch ECG immediately after recording the standard ECG.
Enable the application for ECG recording, which will record a 30 second ECG after proper skin contact with the smartwatch. Record Einthoven one by placing the back of the smartwatch on left wrist and the right index finger on the crown. Then, record Einthoven two by placing it on the left lower abdomen and the right index finger on the crown.
Finally, record Einthoven three in the same position, but with the left index finger on the crown. Ensure that the right and left index finger do not contact the skin of the wrist of lower abdomen and that the subject does not move during the recording. Use the Send PDF to Your Doctor function to create a PDF document of every smartwatch ECG lead.
Then print the digital ECG on paper for comparison with the standard ECG. Classify all smartwatch ECGs as moderate quality if at least three consecutive QRS complexes show noise free signal quality and there are no artifacts in the isoelectric lines between complexes. If this is true for 10 QRS complexes, classify the ECG as good quality.
Then, perform statistical analysis on the ECGs. The smartwatch recording protocol was tested on 100 healthy subjects, all of whom managed the ECG recording procedure after a short tutorial. Of the total recorded ECGs, 92%were of good signal quality and 8%of moderate signal quality.
Despite different writing speeds of the standard and smartwatch ECG curves, the morphologies of the three channels were clearly identical. Three blinded cardiologists were asked to assign the smartwatch ECGs to the corresponding Einthoven leads in each subject and all three correctly assigned the ECGs from 89 participants. All assignment errors were made in the ECGs with good signal quality, but the errors occurred in statistically older subjects.
When attempting this procedure, the most important thing is to perform recordings under resting conditions to obtain best ECG signal quality. Chest lead ECG recordings may also be recorded with mobile device to give additional informations of the interior wall of the left ventricle. This technique may enable widespread of diagnostic potential in an outpatient setting for cardiac disorders.
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Overview
This protocol enables patients to record three bipolar electrocardiograms using a smartwatch, functioning similarly to standard Einthoven leads. This method allows for immediate ECG recording after symptom onset, aiding in the detection of cardiac issues.
Key Study Components
Area of Science
- Electrophysiology
- Cardiology
- Wearable technology
Background
- Smartwatches with ECG capabilities are becoming more prevalent.
- Early detection of cardiac arrhythmias is crucial for patient outcomes.
- Traditional ECGs require clinical settings, limiting immediate patient access.
- This protocol aims to empower patients to monitor their heart health.
Purpose of Study
- To enable patients to record ECGs independently.
- To facilitate immediate identification of ECG abnormalities.
- To assess the feasibility of using smartwatches for ECG recording.
Methods Used
- Utilization of a smartwatch with ECG function.
- Recording three bipolar leads comparable to Einthoven leads.
- Ensuring good skin contact during recording.
- Specific protocol for sending ECG data to healthcare providers.
Main Results
- Patients can successfully record ECGs comparable to standard methods.
- Immediate data collection aids in timely medical intervention.
- Challenges noted in achieving proper lead placement.
- Potential for broader application across various devices.
Conclusions
- This protocol enhances patient engagement in cardiac health monitoring.
- Smartwatch ECG recording can be a valuable tool in clinical practice.
- Further studies are needed to optimize lead placement techniques.
Frequently Asked Questions
Executive Industry Relevance
This protocol enables patient-directed acquisition of three-lead bipolar ECG data using widely available smartwatch technology, addressing a critical gap in outpatient cardiac monitoring. By facilitating immediate symptom-triggered recording, it supports early detection of arrhythmias and myocardial ischemia, thereby enhancing predictive confidence in cardiovascular risk assessment. The approach aligns with decentralized clinical trial models and real-world evidence generation, offering a scalable tool for target validation and mechanistic de-risking in cardiology-focused drug development programs.
Strategic Applications in Biopharma R&D
Early Discovery & Target Validation
- Scientific Value: Enables interrogation of therapeutic hypotheses related to cardiac safety and efficacy through accessible, patient-generated electrophysiological data.
- Operational Value: Supports biological de-risking by providing quantitative, time-synchronized ECG metrics for target engagement and pathway modulation studies.
Screening & Assay Development
- Scientific Value: Prepares validated biological systems (human subjects) for downstream workflows by establishing reliable, reproducible three-lead ECG signal acquisition.
- Operational Value: Addresses assay standardization and reproducibility through defined skin contact protocols and signal quality classification (moderate/good) based on QRS complex clarity and isoelectric line stability.
Translational & Preclinical Research
- Scientific Value: Discusses disease relevance through detection capability for cardiac arrhythmias and myocardial ischemia, enabling translational biomarker alignment in cardiovascular safety pharmacology.
- Operational Value: Describes continuity from discovery through preclinical validation by offering a non-invasive, ambulatory monitoring bridge between in vitro/in vivo models and clinical outcome prediction.
Pipeline & Workflow Integration
The method fits within the discovery continuum from target validation to lead identification, particularly for cardiology indications where electrophysiological safety is a key go/no-go criterion.
- Discovery Biology: Supports hypothesis testing and pathway clarification by enabling measurement of cardiac electrical activity as a functional readout of target modulation.
- Screening: Describes assay readiness through protocol-driven lead placement (Einthoven I, II, III) and immediate post-standard-ECG recording to ensure comparability.
- Analytics: Highlights quantitative dependent variable measurements (QRS complex morphology, signal quality classification) that allow teams to compare conditions and assess inter-subject variability.
- Translational Research: Connects the method to preclinical continuity by enabling correlation of smartwatch ECG features with standard 12-lead ECG benchmarks, supporting risk-adjusted advancement decisions.
- Enterprise Reuse: Frames the method as a reusable capability across therapeutic areas requiring cardiac safety monitoring, reducing dependency on site-based ECG collection.
Operational & Enterprise Impact
- Scientific Value: Predictive confidence in cardiac safety assessment, reduction of mechanistic ambiguity in target validation, and support for phenotypic screening of electrophysiological liabilities.
- Operational Value: Standardization via resting supine protocol, reproducibility across 92% good-quality recordings in healthy subjects, and scalability through consumer wearable deployment.
- Strategic Value: Better go/no-go decisions via early ischemia/arrhythmia detection, capital efficiency by reducing clinical site burden, and reduced late-stage biological risk in cardiovascular drug programs.
- Portfolio Impact: Risk-adjusted prioritization based on ECG signal quality thresholds (e.g., ≥10 noise-free QRS complexes for good quality) and advancement decisions informed by blinded cardiologist lead assignment accuracy (89/100 correct in trial).
Implementation Considerations
- Required scientific expertise in electrophysiology and wearable sensor interface design.
- Instrumentation and analytical infrastructure needs include smartwatch with ECG function, PDF export capability, and paper or digital calipers for QRS complex analysis.
- Cross-team standardization requirements for lead placement training, particularly for Einthoven leads II and III due to lower abdominal positioning challenges.
- Adaptation considerations across model systems limited to human subjects due to reliance on patient-directed device interaction and skin contact.
- Practical limitations include difficulty in achieving optimal skin contact for leads II and III, and reduced assignment accuracy in statistically older subjects despite good signal quality.
