MD Student University of Toronto North York, Ontario, Canada
Background: Recent advances in cardiac monitoring have enabled the development of portable electrocardiogram (ECG) devices with strong validity and practicality. The objective of this pilot study was to evaluate the feasibility of using the KardiaMobile 6-lead ECG (6L-ECG) device as an alternative to the standard 12-lead ECG (12L-ECG) in a high-volume outpatient cardiology clinic to guide clinical management and decision-making.
METHODS AND RESULTS: All patients presenting for an appointment and ECG test at a community cardiology clinic in Toronto, Ontario, received both a 12L-ECG and a 6L-ECG, administered by a trained cardiac technologist. The 6L-ECG device uses three points of contact: two fingers and the left thigh (or ankle) to record leads I and II, and derive leads III, aVR, aVL, and aVF. After each eligible clinical encounter, both 12L-ECG and 6L-ECG reports were uploaded to the electronic medical record. Participating cardiologists completed a cross-sectional survey to evaluate the utility of the 6L-ECG for clinical decision-making. A total of 101 surveys were completed by six cardiologists from March 1 – April 31, 2025. There were 64 follow-up appointments, 32 new consults, and 5 other types of encounters. Each 6L-ECG was interpreted first, followed by the 12L-ECG, and categorized as sinus rhythm, arrhythmia, bradycardia, tachycardia, conduction abnormality, cardiac ectopy, or chamber enlargement. In 87% of patient encounters (88/101), cardiologists reported that the 6L-ECG provided sufficient information to inform clinical decision-making. In 13% (13/101) of cases, the 6L-ECG was deemed insufficient. Reasons for inadequacy included the need for additional 6 leads to confirm diagnoses (6/13), absence of revealing conduction abnormalities (6/13), incorrect rhythm interpretation (2/13), and failure to detect pacemaker activity (2/13). A chi-square test found no significant association between the type of encounter and 6L-ECG sufficiency (χ²=1.91, df=2, p=0.38). Similarly, there was no significant difference in 6L-ECG sufficiency ratings across the six participating cardiologists (χ²=1.71, df=5, p=0.89).
Conclusion: The 6L-ECG is a feasible alternative to the 12L-ECG for the majority of outpatient cardiology encounters and provides sufficient information for routine clinical decision-making. The 12L-ECG remains the gold standard and adds diagnostic value for patients with conduction abnormalities and uninterpretable 6L-ECG recordings. Future, larger scale studies can expand upon this pilot study by assessing the utility of 6L-ECG devices in emergency departments, primary care, and other outpatient specialties. Given the cost-effectiveness and accessibility of 6L-ECG devices, there are real-world opportunities to implement this technology in underserved communities.
