Goldberger leads

  were invented by Dr. Emanuel Goldberger in 1942.

  includes aVR, aVL, and aVF.

  Abbreviations:

a=augmented.

V=Voltage.

R=Right arm, L=Left arm, F=left Foot.

  The purpose of augmentation is to make the ECG waves more perceivable.



How are they recorded?

  aVR: Right arm electrode is connected to the positive terminal of the Galvanometer. Left arm and left foot electrodes are connected to the negative terminal of the Galvanometer. This modification increases the potential of VR by 50%.

  aVL: Left arm electrode is connected to the positive terminal of the Galvanometer. Right arm and left foot electrodes are connected to the negative terminal of the Galvanometer. This modification increases the potential of VL by 50%.

  aVF: Left foot electrode is connected to the positive terminal of the Galvanometer. Left and right arm electrodes are connected to the negative terminal of the Galvanometer. This modification increases the potential of VF by 50%.



Direction of the unipolar limb leads

  aVL: - 30 degrees.

  aVR: - 150 degrees.

  aVF: + 90 degrees.



Reference

  Am Heart J 1942;23:483.