Related Experiment Video
Updated: Jul 5, 2026

Patient Directed Recording of a Bipolar Three-Lead Electrocardiogram using a Smartwatch with ECG Function
Published on: December 11, 2019
Recording electrocardiograms using 3-limb lead cables instead of the standard 4: a modification to minimize incorrect
1Epidemiological Cardiology Research Center (EPICARE), Department of Epidemiology and Prevention, Wake Forest University School of Medicine, Winston Salem, NC 27104, USA. esoliman@wfubmc.edu
Abstract:
The similarity between and the number of limb lead cables play an important role in the frequency of incorrect connection of limb electrodes. Hence, a modified electrocardiogram (ECG) acquisition procedure is proposed in this brief communication, whereby the left-leg (LL) and right-leg (RL) electrode cables are combined into 1 cable, referred to as combined LL/RL cable. The electrode wires in the combined LL/RL cable are connected to 2 electrodes placed on both sides of the LL. The combined LL/RL cable is unique enough (being thicker) not to be mistaken with the upper limb electrode cables. The proposed modification will not in any way influence the ECG waveforms or amplitudes, and it can be expected to substantially reduce incorrect limb electrode placements.
Related Concept Videos
Electrocardiogram Fundamentals
An electrocardiogram (ECG) is a diagnostic tool for identifying cardiac conditions such as arrhythmias, conduction abnormalities, and myocardial ischemia.
Definition
An electrocardiogram (ECG) visualizes the heart's electrical activity by tracing the electrical movement associated with each heartbeat on a graph or monitor. As the heart beats, an electrical wave passes through it, correlating with the cardiac cycle events.
Parts of an ECG
An ECG utilizes electrodes on the skin to...
Electrocardiogram
Three major waveforms are present in a typical ECG recording: the P wave, the QRS complex, and the T...

