Among many institutes, Seoul National University Hospital Including Children's Hospital has played a leading role up to date.

Clinical data following the first open heart surgery on August 7,1959 up to December 1993 revealed that the total number of open heart surgery was cises in Seoul National University Hospital and overall mortality was 6.8%.

Since 1977, the cases of open heart surgery has rapidly increased due to two main reasons : Accumulation of untreated cardiac patients and widening coverage by national medical insurance. The number of cases exceeded 100 in 1978, 400 in 1980, 600 in 1982 and 700 in 1986. In the second half of 1980's and 1990's the number of cases were over 700 per year.

The ratio of congenital to acquired heat disease was 1.5:1 , and that of acyanotic to cyanotic congenital cardiac anomaly was 2.0: 1. The order of frequency of acyanotic group was Ventricular Septal Defect(56.4%), Atrial Septal Defect(28.6%), Endocardial Cushion Defect(4.6%), Pulmonary Stenosis(2.9%) and Patent Ductus Arteriosus(1.0%). Whereas the incidence of cyanotic group was Tetralogy of Fallot(57.5%), Transpotion of Great Arteries(9.5%),Double Outlet Right Ventricle(8.7%) and Pulmonary Atresia(5.7%). The overall mortality of acyanotic congenital heart disease was 2.9% and that of cyanotic congenital heart disease was 16.7%. Transposition of Great Arteries, Pulmonary Atresia and Truncus Arteriosus especially resulted in very high mortality,25-30%. The causes of high mortality in these group were inadequate patient selection for operation, inexperienced perioperative neonatal care and unskiled operative technique, but the figure was remarkebly improved since 1990, and now operative mortality reached under 10%.

In 2019 cased of valvular heart disease, single mitral valve disease was most common (1139 cases) and double valvular disease was 534 cases and triple valvular disease was 41 cases. According to the order of frequency in redo valvular disease was 6,0%.

The frequency of ischemic heart disease and aortic disease were not so frequency previously but these figures rapidly increase in recent days. The first CABG was performed at this hospital in 1981 and 240 cases have been performed by 1993.Overall mortality was 7.1%. The number of cases in 1993 was increased two times compared to 1992, but the mortality was decreased to 2.4%. Acute aortic dissection (57 cases) was most common among 127 cases of aortic disease which was operative mortality was 26.3% which was very high. Mortality gradually decreased recently down to zero because of appropriate brain protection technique including deep hypothemia, circulatory arrest and selective cerebral perfusion.

In Korea, brain death is not accepted by law as well as traditional concept. However in 1993 and up to now, five cases of heart transplantation were performed by voluntary consent of familly of the donor and recipient.