ECGs were examined in 88 cases before and after operation. After operation, ECG was taken on the second, fourth and sixth day. Fourty-two cases (48%) showed some changes in ECG after operation.
Patients with gastric cancer showed some changes most frequently (63%). Among the post operative changes, T wave change was more common. Hypertension, bleeding, variation of blood pressure during operation and operation time had influence on the ECG. Serum potassium was prove to be lowered after operaiion.