The results of selective eitracardial pacemaker done in 53 of 162 cases after various open-heartoperations wii th cardiopulmunary bypass were presented between Dec. 1980 to Jun. 1983. ( 1 )After operation 36 of 53 patients were planted by extracardial pacemaker for preventive application. (2) After operation 17 cases required pacing. 14 out of 17 patients were effective

duration varied in pacing time from 22 rain

to 7 days; another were noN-effective

it may be results of acute heart failure or incompleted corrective malformation of the heart. (3) The vein infusion isoprenaline may reduce threshold valne of pacing.There were tentative CAVB

bradycardia after operation of complicate congenital heart disease and valve replacement

since operative time may be longer or atrioventricular conduction bundle was stimulated. Author recognized that tentative extracardial pacemeker was required by planting after operation 2 week duration