Einthoven’s triangle-ECG Question-2

Which is TRUE for potentials in Einthoven’s triangle?

[A] I + II = III
[B] I + III = II
[C] I – III = II
[D] III + II = I



Einthoven’s triangle

Einthoven’s triangle

  • I = LA – RA
  • II = LL- RA
  • III = LL – LA

Lead I — This axis goes from shoulder to shoulder, with the negative electrode placed on the right shoulder and the positive electrode placed on the left shoulder.

Lead II — This axis goes from the right arm to the left leg, with the negative electrode on the shoulder and the positive one on the leg.

Lead III — This axis goes from the left shoulder (negative electrode) to the right or left leg (positive electrode).