After the left and right hands of the ECG are connected in reverse, the graph of the ECG will be disturbed, and some leads will be just the opposite compared to the normal condition. 1. Chest leads V1~V6 will not change because the electrical end of the center will not change. 2. AVF will not change, but because the positive and negative poles are reversed, AVL will appear as AVR, and vice versa, AVR will appear as AVL. 3. Normal electrocardiogram has a downward P-wave in the AVR lead, an upward P-wave in the I lead and the AVL lead, a downward main wave, and an inverted T-wave. When the left and right hands are connected inversely, the P wave of AVR lead is upward, the P wave of I lead and AVL lead is downward, the direction of main wave is upward, and the T wave is upright, which is opposite to the normal electrocardiogram. If there is an abnormal ECG result, it is recommended to consult a doctor in time, clarify the cause of the disease with the help of a doctor, and carry out targeted treatment or therapy.