Limb Lead Reversal ECG Review

If the limb lead that was supposed to be attached to the right arm is put on the left arm — and vise-versa — a characteristic appearance will be seen on ECG that includes:

1. Predominantly negative P wave, QRS complex and T wave in lead I.
2. Predominantly upward P wave, QRS complex and T wave in aVR.

This is opposite of what is seen in a normal ECG. The above findings are similar to that seen in a person with dextrocardia; however, if the heart is located in the right side of the chest instead of the left, the voltage in leads V3-V6 will be very low. This would not be seen in simple limb lead reversal.

ECG Examples:

• Limb lead reversal ECG Example 1
• Limb lead reversal ECG Example 2

References:

1. Chou's Electrocardiography in Clinical Practice: Adult and Pediatric, Sixth Edition, Saunders, Philadelphia, 2008.
   
2. Surawicz B et al. ACC/AHA recommendations for the standardization and interpretation of the electrocardiogram. Circulation. 2009;119:e235-240.