Why 6-LEAD?

Advantage of 6-Lead

Why 6-lead is better than 1-lead?

The front and the side of a person, and the front and the side of a dog are different.
Which one do you think is right?

• 1-lead provides only one photo. (lead I)

• On the other hand, 6-lead provides 6 photos. (lead I, II, III, lead aVR, aVL, aVF)

  • Depending on the angle, the image you see is different.
  • They look similar from the front, but different from the side.
The central axis of the heart that affects the electrocardiogram waveform varies from person to person.

• Therefore, if you take pictures of the heart from various angles, you can receive more accurate diagnostic information.
• The 6-lead measures the state of the heart in six different angles and directions.

When accurate diagnosis is difficult with a single lead, multiple leads increase the accuracy of diagnosis with the remaining leads.

• Depending on the electrical vectors of the left atrium and right atrium, the optimal leads for visualizing P waves vary depending on the patient.

Information about other leads as well as lead-I is useful when diagnosing arrhythmia.

• The P-wave can be seen well in Lead II. (Reference 3)
• Right atrial dilatation should be noted if the height of P-wave in Lead II is greater than 2 to 2.5 mm. (Reference 1)
• Sinus rhythm of low power (SR-LAP) and atrial flutter(AFL) are not found well in lead-I. (Reference 2)
• Lead I, aVR and v5 of the 12 leads contributes more when judging arrhythmia. (Reference 3)
• Although all single leads performed good for atrial fibrillation, lead II and aVR showed the best performance. (Reference 3)
• It was judged that the historically overlooked lead aVR was useful in ECG interpretation. (Reference 3)


1 : Easy-to-understand electrocardiogram, p94, Roh Tae-Ho, Book Publishing, Korean Medicine
2 : Improved accuracy and confidence with multiple‐lead recordings from a single‐lead mobile electrocardiographic device, August 2019, Pacing and Clinical Electrophysiology 42(9)
3. Interpretable deep learning for automatic diagnosis of 12-lead electrocardiogram, April 23, 2021, ISCIENCE, vol.24 issue 4