Abstract
The daily changes in pacing threshold were measured on 30 patients with implanted pacemakers, using “Vario function” and Holter ECG. 15 patients showed the changes; in 8 patients the threshold increased in the night. In 2 patients who were implanted for 1 to 3 weeks, the threshold gradually increased until 7 or 8 postoperative days and then decreased. Especially for such patients, We need to measure the daily changes in pacing threshold.