Korean J Pediatr 2011;54(5):192-200 • DOI: 10.3345/kjp.2011.54.5.192 195 similar to those of AAP22). However, RSV hospitalization has not been eliminated in CHD patients receiving prophylaxis, as palivizumab tends to attenuate but not eradicate RSV disease21-25). Significant controversy remains regarding the cost effectiveness of palivizumab prophylaxis in high- risk patients, including those with CHD25,26). Eventually this may be considered as the limitation of passive immunization. Even subsequent studies have a decreasing trend in mortality, both medical and surgical morbidity, e.g. RSV hospitalization requiring intensive care and oxygen supply and need for mechanical ventilation, caused by RSV remain significant high though it varies with the degree of cardiac compromise21,22,24,25). In infant with HS- CHD, major issues by result of RSV infection are considered as the compromised cardio-pulmonary function during perioperative period, caused by pulmonary hypertension, bi-ventricular functional failure, and deoxygenation. Recently as to the development of intensive care, including brand-new mechanical ventilation and selective pulmonary vasodilators, it looks impossible to make the treatment available even in serious RSV infected infants5). The chronic effects of RSV infection on lung are not only confined to acute morbidity, but there may also be long-term sequelae5,9). A long-term prospective study for 7.5 years, provide strong evidence that RSV bronchiolitis in infancy is associated with a higher risk of developing subsequent bronchial obstructive disease in the development of asthma and allergy at least in some children. Korean experiences of Respiratory Syncytial virus infection with congenital heart diseases Similarly in Korea, there were a few of initial reports for intervening in serious and fatal cases with CHD superimposed by RSV infection, and still remains as a painful memories for some pediatric cardiologists27). According to a Korean study reported in 2010, 76 children with 45 CHD and 31 non-CHD patients infected by RSV were evaluated, just before palivizumab era, from 2003 to 200627). Of total 71 patients, 22 (48.9%) were treated in intensive care in 3 of non-CHD patients (9.7%), 12 (26.7%) were required mechanical ventilation but none in non-CHD patients, and 2 (4.4%) mortalities of CHD patients were noticed none in non-CHD patients. Korean public health insurance guidelines recommend the use of palivizumab in children less than 1 year of age with HS- CHD since 2009. The categories of theses HS-CHD include pulmonary hypertension, cyanotic heart diseases, and CHD treated by medication for congestive heart failure. Since palivizumab was introduced to premature infants of Korea in 2007, the total number of infants receiving palivizumab has more than doubled annually. A preliminary survey for pediatric cardiologists done after 2009 RSV season revealed that 40% thought that palivizumab was quite effective; another 40% thought that it may be effective in Korea. In addition, about 1.8 doses of palivizumab were used in limited pediatric centers. Current data has been collected on the effectiveness of RSV prophylaxis with palivizumab in infants with CHD in Korea. Conclusion Infants with CHD represent a group that is at a higher risk for morbidity from RSV infection. RSV infection is further threatening to particular conditions of CHD patients: infants with congestive heart failure, cyanosis, or pulmonary hypertension. Under these cardiac conditions, CHD patients are severely restricted in capacity of cardiac function to increase cardiac output and oxygen delivery. As RSV pneumonitis progresses in those infants with compromised cardiac performance, oxygen uptake is markedly impaired and the work of breathing is gradually increased. A few reports of RSV experiences in Korea were similar to those of global data. Eventhough fatal cases with CHD superimposed by RSV infection are still under concern, RSV prophylaxis using palivizumab and powerful advances in intensive care has been shown to reduce RSV mortality and morbidity in infants with HS CHD, particularly those with palliated complex disease, unrepaired serious CHD and those with significant residual defects after cardiac surgery. References 1. Howard TS, Hoffman LH, Stang PE, Simoes EA. Respiratory syncytial virus pneumonia in the hospital setting: length of stay, charges, and mortality. J Pediatr 2000;137:227-32. 2. Nair H, Nokes DJ, Gessner BD, Dherani M, Madhi SA, Singleton RJ, et al. Global burden of acute lower respiratory infections due to respiratory syncytial virus in young children: a systematic review and meta-analysis. Lancet 2010;375:1545-55. 3. Hall CB, Weinberg GA, Iwane MK, Blumkin AK, Edwards KM, Staat MA, et al. The burden of respiratory syncytial virus infection in young children. N Engl J Med 2009;360:588-98. 4. MacDonald NE, Hall CB, Suffin SC, Alexson C, Harris PJ, Manning JA. Respiratory syncytial viral infection in infants with congenital heart disease. N Engl J Med 1982;307:397-400. 5. Wright M, Piedimonte G. Respiratory syncytial virus prevention and therapy: Past, present, and future. Pediatr Pulmonol 2011;46:324-47. 6. Thompson WW, Shay DK, Weintraub E, Brammer L, Cox N, Anderson LJ, et al. Mortality associated with influenza and respiratory syncytial virus in the United States. JAMA 2003;289:179-86. 7. The Impact-RSV Study Group. Palivizumab, a humanized respiratory syncytial virus monoclonal antibody, reduces hospitalization from respiratory syncytial virus infection in high-risk infants. Pediatrics