It is generally difficult to recognize this type of lead misplacement if there is no previously recorded

      normal ECG to compare with.

  Among the limb leads, only the lead aVR is not affected by this type of lead misplacement.



It has been suggested that the following ECG findings are usually observed in patients with
left arm left leg lead reversal :

  The P wave amplitude in lead II is lesser than the P wave amplitude in lead I.

  If the lead III has biphasic P waves, then the terminal half of the P wave is upward.



If the patient has WPW syndrome or ectopic atrial rhythm, the above two signs may not be so helpful

in detecting the left arm left leg lead reversal .




         
ECG 1a (left) and 1b (right). The compact ECGs above belong to a 27 years-old woman with WPW syndrome.

ECG 1a was recorded with correctly positioned electrodes. ECG 1b was recorded with reverse connection of the left arm and

left leg electrodes.



         
ECG 2a (left) and 2b (right). The compact ECGs above belong to a 71 years-old man with coronary artery disease.

ECG 2a was recorded with correctly positioned electrodes. ECG 2b was recorded with reverse connection of the left arm and

left leg electrodes.