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Cardiac resynchronization therapy (CRT) is an effective treatment for heart failure. However, in pediatric and congenital heart disease (CHD) patients, current adult indications cannot be directly applied because of heterogeneity in anatomy and diagnosis. Therefore, CRT responses and clinical outcomes in these patients were investigated to derive possible candidates for CRT.This study retrospectively analyzed 16 pediatric and CHD patients who underwent CRT implantation at a single center in early (0.7±0.2 year) and late (4.7±0.3 years) follow-up period after CRT.The median age at CRT implantation was 2.5 (0.3-37.2) years, and median follow-up duration was 6.3 (0.1-13.6) years. Thirteen had non-transvenous CRT. Two had congenital complete atrioventricular (AV) block with previous right ventricular pacing, 5 had dilated cardiomyopathy (DCM) with left bundle branch block, and 9 had CHD. The mean ejection fraction of the systemic ventricle increased from 28.1±10.0% to 44.3±21.0% (p=0.003) in early and 51.8±16.3% (p=0.012) in late outcome. The mean functional class improved from 3.1±0.9 to 1.8±1.1 after CRT (p=0.003). Twelve patients (75%) showed improvement in ventricular function or functional class after CRT. Proportion of responders differed between patients without CHD (2/2 patients with complete AV block and 5/5 with DCM, 100%) and those with CHD (5/9, 56%), although statistical significance was not reached (p=0.088).CRT improved ventricular function and functional status according to the underlying condition in pediatric and CHD patients. However, further large and longer-term studies are needed to establish the guideline for the patient selection of CRT in these patients.

Protein-losing enteropathy (PLE) is a devastating complication after the Fontan operation. This study aimed to investigate the clinical characteristics, treatment response, and outcomes of Fontan-associated PLE.We reviewed the medical records of 38 patients with Fontan-associated PLE from 1992 to 2018 in 2 institutions in Korea.PLE occurred in 4.6% of the total 832 patients after the Fontan operation. After a mean period of 7.7 years after Fontan operation, PLE was diagnosed at a mean age of 11.6 years. The mean follow-up period was 8.9 years. The survival rates were 81.6% at 5 years and 76.5% at 10 years. In the multivariate analysis, New York Heart Association Functional classification III or IV (p=0.002), low aortic oxygen saturation (90%) (p=0.003), and ventricular dysfunction (p=0.032) at the time of PLE diagnosis were found as predictors of mortality. PLE was resolved in 10 of the 38 patients after treatment. Among medical managements, an initial heparin response was associated with survival (p=0.043). Heparin treatment resulted in resolution in 4 patients. We found no evidence on pulmonary vasodilator therapy alone. PLE was also resolved after surgical Fontan fenestration (2/6), aortopulmonary collateral ligation (1/1), and transplantation (1/1).The survival rate of patients with Fontan-associated PLE has improved with the advancement of conservative care. Although there is no definitive method, some treatments led to the resolution of PLE in one-fourth of the patients. Further investigations are needed to develop the best prevention and therapeutic strategies for PLE.

BACKGROUND AND OBJECTIVES We reviewed the long-term outcomes after tetralogy of Fallot (TOF) repair with trans-annular incision; and evaluated the effectiveness of pulmonary valve replacement (PVR) on outcomes. METHODS This was a retrospective review of clinical outcomes of 180 of 196 TOF patients who underwent total correction with trans-annular incision from 1991 to 1997 (PVR group: 81; non-PVR group: 99). RESULTS The median age of the patients was 14.0 months (interquartile range [IQR], 10.7-19.8 months) at TOF repair. Ten in-hospital deaths (5.1%) occurred. During the follow-up, 81 patients underwent PVR at the median age of 13.5 years (IQR, 11.2-17.1 years). The patients in PVR group showed better outcomes than non-PVR group in overall survival rate (100% in PVR vs. 88.7% in non-PVR, p=0.007), in all adverse events (arrhythmia, neurologic complications, 95.5% in PVR vs. 74.6% in non-PVR, p=0.024) at 20 years. Age at TOF repair younger than 1 year (hazard ratio [HR], 2.265; p=0.01) and previous shunt history (HR, 2.195; p=0.008) were predictive for requiring PVR. During follow-up, 10 late deaths (5 sudden deaths) occurred in the non-PVR group, mainly due to ventricular arrhythmia and right ventricular failure; there was 1 late death (not a sudden death) in the PVR group. CONCLUSIONS Long-term survival after repair of TOF with trans-annular incision were acceptable. However, arrhythmias were frequently observed during 20 years of follow-up. The patient age

Although long QT syndrome (LQTS) is a potentially life-threatening inherited cardiac channelopathy, studies documenting the long-term clinical data of Korean patients with LQTS are scarce.This retrospective cohort study included 105 patients with LQTS (48 women; 45.7%) from a single tertiary center. The clinical outcomes were analyzed for the rate of freedom from breakthrough cardiac events (BCEs), additional treatment needed, and death.LQTS was diagnosed at a median age of 11 (range, 0.003-80) years. Genetic testing was performed on 90 patients (yield, 71.1%). The proportions of genetically confirmed patients with LQTS types 1, 2, 3, and others were 34.4%, 12.2%, 12.2%, and 12.2%, respectively. In the symptomatic group (n=70), aborted cardiac arrest was observed in 30% of the patients. Treatments included medications in 60 patients (85.7%), implantable cardioverter-defibrillators in 27 (38.6%; median age, 17 years; range, 2-79 years), and left cardiac sympathetic denervation surgery in 7 (10%; median age, 13 years; range, 2-34). The 10-year BCE-free survival rate was 73.2%. By genotype, significant differences were observed in BCEs despite medication (p0.001). The 10-year BCE-free survival rate was the highest in patients with LQTS type 1 (81.8%) and the lowest in those with multiple LQTS-associated mutations (LQTM). All patients with LQTS survived, except for one patient who had LQTM.Good long-term outcomes can be achieved by using recently developed genetically tailored management strategies for patients with LQTS.

Author's summary The effect of diuretics on ASD size reduction remains unclear. In pediatric patients with a large secundum ASD (≥10 mm), diuretic administration seemed to be associated with changes in ASD size. There seemed to be a little possibility of ASD size reduction in case of rim deficiency other than the aortic rim. The patients receiving diuretics may have a lower possibility to undergo surgical closure. The diuretics administration may be associated with the use of smaller ASD devices., Background and Objectives While diuretics are sometimes used in atrial septal defect (ASD) treatment, their effect on ASD size reduction remains unclear. We aimed to evaluate the efficacy of diuretics in ASD size reduction in pediatric patients. Methods We retrospectively reviewed the medical records of patients with secundum ASD (size ≥10 mm), between 2005 and 2019. Patients were divided into two groups based on the diuretic administration. Results Of the 73 enrolled patients, 40 received diuretics. The initial age at ASD diagnosis (2.8±1.7 vs. 2.5±2.0 years, p=0.526) and follow-up duration (22.3±11.4 vs. 18.7±13.2 months, p=0.224) were not significantly different between the groups. The ASD diameter at the initial diagnosis (13.7±2.0 vs. 13.5±3.4 mm, p=0.761) and the indexed ASD diameter (25.5±5.9 vs. 26.9±10.3 mm/m2, p=0.493) were also not significantly different between two groups. The ASD diameter significantly increased in the non-diuretic group during follow-up (0.0±2.9 vs. +2.6±2.0 mm, p

Acute giant coronary aneurysm after Kawasaki disease (KD) is a catastrophic complication that can be fatal and very difficult to manage. However, no fixed consensus has been reached for the management of super-giant coronary aneurysms in the acute setting. Here, we report the successful management of young children with super-giant coronary aneurysms after KD. Based on our experience, hemodynamic stabilization to prevent further coronary dilation or rupture and strict anticoagulation to avoid thrombus formation are mandatory in the management of this condition.

Background and Objectives We hypothesized that fetal echocardiography (echoCG) is an accurate diagnostic tool reflecting well postnatal echoCG findings and outcomes. Subjects and Methods We reviewed the medical records of 290 pregnant women, including 313 fetuses, who were examined by fetal echoCG at the Seoul National University Children's Hospital from January 2008 through April 2011. Results The mean gestational age at diagnosis was 26.2±5.2 weeks. The mean age of mothers at diagnosis was 31.7±3.8 years. We identified indications for fetal echoCG in 279 cases. The most common indication was abnormal cardiac findings in obstetrical screening sonography (52.0%). Among the 313 echoCG results, 127 (40.6%) were normal, 13 (4.2%) were minor abnormalities, 35 (11.2%) were simple cardiac anomalies, 50 (16.0%) were moderate cardiac anomalies, 60 (19.2%) were complex cardiac anomalies, 16 (5.1%) were arrhythmias, and 12 (3.8%) were twin-to-twin transfusion syndrome. The most common congenital heart disease was tetralogy of Fallot (23 fetuses, 15.9%). One hundred forty-eight neonates were examined by echoCG. We analyzed differences between fetal echoCG and postnatal echoCG. In 131 (88.5%) cases, there was no difference; in 15 (10.1%), there were minor differences; and in only 2 (1.4%) cases, there were major differences. Conclusion There is a recent increase in abnormal cardiac findings of obstetric ultrasonography screenings that indicate fetal echoCG. Fetal echoCG is still a good, accurate diagnostic method for congenital heart disease.

Background and objectives Some patients with Kawasaki disease (KD) develop large coronary aneurysms and subsequent coronary stenosis or obstruction, leading to ischemic heart disease. This study examined the long-term outcomes of patients with KD complicated by large coronary aneurysms. Subjects and methods The medical records of 71 patients (53 men and 18 women) diagnosed with large coronary aneurysms (diameter ≥6 mm) between December 1986 and December 2013 were retrospectively reviewed from our institutional database. Results The mean age at onset was 4.6±3.3 years, and the mean follow-up duration was 12.5±6.9 years. Maximum coronary artery internal diameter ranged from 6.1 to 25 mm. Giant coronary aneurysms occurred in 48 patients and coronary aneurysms 6-8 mm in diameter developed in 23 patients. Coronary stenosis and/or complete occlusion occurred in 30 patients (42.3%). Catheter and/or surgical interventions (mean: 1.5 interventions, range: 1-5 interventions) were performed in 20 patients (28.2%), 9 months to 18 years after KD onset, resulting in 33.7% cumulative coronary intervention rates at 20 years after onset. There were no differences in cumulative coronary intervention rates between two coronary aneurysm groups (6-8 mm vs. ≥8 mm). Myocardial infarction occurred in 7 patients with a giant aneurysm and there was one death. Conclusions Long-term survival of patients with KD complicated by large coronary aneurysm was good even though 28.2% of patients underwent multiple catheter or surgical interventions. Careful follow-up is also necessary in KD patients with coronary aneurysms 6-8 mm in diameter, such as those with giant aneurysms.

Background and Objectives: Vascular rings refer to anomalies of the great arteries that cause respiratory or feeding problems. The purpose of this study was to analyze a series of patients with vascular rings and evaluate associated risk factors for mortality. Subjects and Methods: A retrospective review of all patients identified with vascular rings between 1997 and 2010 in the Seoul Nation al University Children’s Hospital. Results: Thirty-five patients were diagnosed with vascular rings (median age at diagnosis, 7 months). The vascular rings of 32 patients were confirmed by cardiac computed tomography or magnetic resonance imaging. The types of vascular rings were: a double aortic arch in ten patients, a right aortic arch with persistent left ligamentum arteriosum in seven, an aberrant subclavian artery in seven, a pulmonary sling in eight, and others types in three patients. Eleven patients were asymptomatic. Gastrointestinal and respiratory symptoms were seen in ten and sixteen patients, respectively. Associated cardiovascular anomalies were present in fifteen patients. Twenty patients with definite symptoms underwent surgical treatment. The median interval between diagnosis and operation was 6 days. Four patients eventu ally died; three deaths were associated with complex heart diseases, and one had pulmonary artery sling with severe tracheal stenosis. Only the presence of a complex heart disease significantly influenced mortality (p=0.002). Conclusion: Vascular rings include several types of anomalies, each with a different prognosis and symptoms. The presence of a complex heart disease was significantly associated with mortality. Early diagnosis and timely surgery in symptomatic patients are essential. (Korean Circ J 2012;42:252-258)

Background and Objectives: With the increasing survival of preterm infants, pulmonary hypertension (PH) related to bronchopulmonary dysplasia (BPD) has become an important complication. The aim of this study was to investigate the characteristics and outcome of PH in preterm infants with BPD and to identify the risk factors for PH. Subjects and Methods: We reviewed the records of 116 preterm infants with BPD cared for at a single tertiary center between 2004 and 2008. Results: Twenty-nine (25%) infants had PH >2 months after birth. PH occurred initially at a median age of 65 days (range, 7-232 days). Severe BPD, a birth weight

Background and objectives Multifocal atrial tachycardia (MAT), in general, has a favorable outcome. However, there are insufficient data regarding MAT in a pediatric population. This study sought to determine the clinical course of MAT and identify potential prognostic factors. Methods The medical records of MAT patients from 1997-2015 were reviewed. The arrhythmia control rate and factors for unfavorable outcomes were assessed and compared to those in the literature. Results Of the 33 included patients (19 boys and 14 girls), 27 were infants less than 1 year of age. The median age at diagnosis was 1.7 months (range, 0 day to 14 years). Fourteen (42%) patients had structural heart disease. Eight (24%) patients had lung disease and 6 (18%) had a syndromic diagnosis belonging to RASopathy. Two patients developed polymorphic ventricular tachycardia, in whom genetic analysis confirmed the presence of the RyR2 mutation several years later. MAT was controlled in 26 patients (84%) within 3.9 months (median; range, 16 days-18.4 years) using an average of 2.4 medications. There were 3 cases of cardiopulmonary mortality. The arrhythmia control rate was higher in the infant group (85%) than in the non-infant group (67%), although this trend was not statistically significant. There was a significantly lower rate of unfavorable outcomes in the idiopathic infant group (n=11) than in the other groups (p=0.008). Considering the findings of previous studies, the mortality rate was significantly higher in patients with structural heart disease than in patients without (21% vs. 5%, p=0.01). Conclusions MAT usually affects infants and has a favorable prognosis, particularly in the idiopathic infant group. However, in the presence of other comorbidities, MAT may have a variable clinical course.

Background and Objectives: Only a few studies have specifically investigated the reasons for emergency room (ER) visits in patients with congenital heart disease (CHD). The aim of this study was to identify the major reasons for ER presentation among patients with CHD that were acutely and seriously ill at a tertiary medical center in Korea. Subjects and Methods: All 368 admissions of patients with CHD via the ER from 2003 to 2008 were enrolled. We conducted a retrospective study with review of the medical records. Results: Eighty two patients were newly diagnosed as having CHD. Their major presentations were: symptoms of heart failure (41.5%), murmur (31.7%), and cyanosis (18.3%). There were 286 visits that were cases with known CHD. Their major presentations were respiratory tract infection (24.1%, 2.7±4.1 years of age), dysrhythmia (16.4%, 16.7±9.5 years), symptoms of heart failure (14.3%, 7.6±9.4 years), aggravated cyanosis (5.6%, 0.8±1.4 years), protein-losing enteropathy (4.9%), hemoptysis (4.5%), drug side effects (4.1%), and infective endocarditis (3.0%). There were significant correlations between the age distributions and major modes of presentation. Surgical treatments were required within 1 month in 38%, and 2.7% of all patients died during hospitalization. The patient group with respiratory infections and CHD showed the highest mortality (5.8%). Atrial flutter was the most frequent arrhythmia (70.2%) and 70% of these patients were post-Fontan surgery condition. The causes of heart failure in the patients with previous surgical repair were: pulmonary hypertension, myocardial dysfunction, valve regurgitation, and uncorrected lesions. Conclusion: Improved understanding of the common problems in the ER can help prepare clinicians to manage patients that present with CHD. (Korean Circ J 2010;40:36-41)

Pulmonary thromboembolism is a very rare event in children, but the mortality rate is reported to be approximately 10%. The majority of children with thromboemboli have multiple risk factors, such as a catheter-related thrombosis, an infection, and a congenital prothrombotic disorder. Hypereosinophilia is very rarely associated with pulmonary emboli in adults; however, this condition has not been reported in children. We present a 12-year-old boy who had a pulmonary thromboembolism and deep vein thrombosis associated with hypereosinophilia and thrombocytopenia. The thromboembolism was managed with anticoagulant therapy and the hypereosinophilia resolved spontaneously.

BACKGROUND AND OBJECTIVES Cardiac catheterization is used to diagnose structural heart disease (SHD) and perform transcatheter treatment. This study aimed to evaluate complications of cardiac catheterization and the associated risk factors in a tertiary center over 10 years. SUBJECTS AND METHODS Total 2071 cardiac catheterizations performed at the Seoul National University Children's Hospital from January 2004 to December 2013 were included in this retrospective study. RESULTS The overall complication, severe complication, and mortality rates were 16.2%, 1.15%, and 0.19%, respectively. The factors that significantly increased the risk of overall and severe complications were anticoagulant use before procedure (odds ratio [OR] 1.83, p=0.012 and OR 6.45, p

Management of severely dilated pulmonary artery (PA) associated with severe pulmonary hypertension from congenital heart disease remains controversial, primarily due to its rare nature and concern for perioperative unpredictable complications. Herein, we report a 25 year-old female with a severely dilated PA (up to 73 mm), who was successfully treated by a PA graft replacement by creating a Y-shaped conduit using a 28 mm hemashield tube in the main PA and a 20 mm hemashield tube in both proximal parts of the branch PA.

Background and objectives We studied the results of patient management for left isomerism (LI) and sought to determine factors that may influence survival and prognosis. Subjects and methods We reviewed the medical records of 76 patients who were compatible with LI criteria between 1982 and 2014. Results Of the total study population, 29 patients (38.1%) had functional univentricular heart disease, 43 patients (56.5%) had cardiac anomalies suitable for biventricular hearts, and four patients (5.2%) had normal heart structure. Extracardiac anomalies were noted in 38.1% of the study population, including biliary atresia in 7.8% of all patients. Of the 25 patients who underwent Kawashima procedures, 24.0% developed pulmonary arteriovenous fistulas (PAVFs). During the median follow-up period of 11.4 years (range: 1 day to 32 years), 14 patients died. The 10-year, 20-year, and 30-year survival rates were 87%, 84%, and 76%, respectively. Preoperative dysrhythmia and uncorrected atrioventricular valve regurgitation were significantly associated with late death. There was no significant difference in the number of surgical procedures and in survival expectancy between patients in the functional single-ventricle group and in the biventricular group. However, late mortality was higher in functional single-ventricle patients after 18 years of age. Conclusion Patients with LI need to be carefully followed, not only for late cardiovascular problems such as dysrhythmia, valve regurgitation, and the development of PAVFs, but also for noncardiac systemic manifestations.

Unguarded tricuspid regurgitation (TR) due to a flail tricuspid leaflet is a rare condition of newborn cyanosis. A high perinatal mortality has been associated with this fatal condition. But, there are feasible surgical repairs to improve survival. We report the case of a male full-term neonate with intractable hypoxia. He had profound tricuspid insufficiency and leaflet prolapse caused by a ruptured papillary muscle supporting the anterior leaflet of the tricuspid valve. He presented with severe cyanosis and respiratory distress immediately after birth. Despite medical management, the pulmonary vascular resistance was not decreased and a low cardiac output persisted. Initial stabilization was accomplished with nitric oxide and extracorporeal membrane oxygenation. The tricuspid valve repair surgery was successfully performed subsequently. TR resulting from papillary muscle rupture is a potentially lethal condition. Timely diagnosis and proper surgical treatment can be lifesaving.

QT prolongation is a serious adverse drug effect, which is associated with an increased risk of Torsade de pointes and sudden death. Many drugs, including both cardiac and non-cardiac drugs, have been reported to cause prolongation of QT interval. Although meperidine has not been considered proarrhythmic, we present a unique case of a 16-year-old boy without an underlying cardiac disease, who developed polymorphic ventricular tachycardia, ventricular fibrillation and QT prolongation after an intravenous meperidine injection. He had no mutation in long QT syndrome genes (KCNQ1, KCNH2, and SCN5A), but single nucleotide polymorphisms were reported, including H558R in SCNA5A and K897T in KCNH2.

Since the first descriptions of Brugada as a new clinical entity defined by sudden cardiac death in patients with typical electrocardiogram (ECG) patterns, Brugada syndrome (BS) has been increasingly diagnosed. This syndrome is known as a disease that is inherited via an autosomal dominant trait, and the SCN5A mutation has been found in 20-25% of BS patients. Because BS primarily manifests in adulthood, little information is available on BS during childhood. Although there have been several reports on adult BS in Korea, pediatric BS has not been reported. Herein, we report on childhood BS in two families. One infantile BS patient and his family had a novel SCN5A mutation (c.4035G>T, p.W1345C, heterozygote) in domain III of the sodium channel.

Background and Objectives: Although coronary artery obstruction, aortic insufficiency (AI), and pulmonary stenosis (PS) have been reported after arterial switch operation (ASO), limited long-term studies on ASO exist. Our study aimed to examine long-term outcomes after ASO for simple complete transposition of the great arteries (TGA). Subjects and Methods: All 108 patients with simple complete TGA who underwent ASO at Seoul National University Children’s Hospital between 1987 and 2004 were enrolled. We retrospectively reviewed the patients’ medical records and the results of various functional and imaging studies. Results: Among 108 cases of ASO for simple TGA, 96 have been followed-up through the present time (mean follow-up duration was 11.7±8.6 years: range= 4 to 23 years). The 20-year rates of freedom from significant AI, PS, and coronary obstruction were 78.6%, 67.8%, and 95.8%, respectively. AI showed a tendency to progress as follow-up time increased in 21.4% of the population studied (p=0.014); however, AS, PS, and PI showed no such progression. Late coronary artery occlusion was not associated with the initial coronary arterial pattern. Re-operations were done for 13 patients (13.5%) at an average of 8±4.3 years after ASO. The survival rate was 96%, while the re-operation-free was 90% at 10 years and 83% at 20 years. Most patients showed normal physical growth with good activity {98%; New York Heart Association (NYHA) class 1 activity} and normal development (96%). Conclusion: Although most patients showed normal physical growth and development after successful ASO, meticulous long-term follow-up is necessary because of progressive AI and coronary complications. (Korean Circ J 2010;40:23-30)

Background and Objectives Milrinone is often used in children to treat acute heart failure and prevent low cardiac output syndrome after cardiac surgery. Due to the lack of studies on the long-term milrinone use in children, the objective of this study was to assess the safety and efficacy of the current patterns of milrinone use for ≥3 days in infants and children with heart diseases. Subjects and Methods We retrospectively reviewed the medical records of patients aged

Background and Objectives In Duchenne and Becker muscular dystrophies, cardiac function deteriorates with time resulting in heart failure which is often fatal. We prospectively evaluated the effect of enalapril and carvedilol on left ventricular (LV) dysfunction in middle childhood and adolescent patients with muscular dystrophy. Subjects and Methods Twenty-three patients with LV dysfunction (22 with Duchenne muscular dystrophy, 1 with Becker muscular dystrophy) were enrolled. We prescribed enalapril (13 patients) or carvedilol (10 patients) randomly from July 2008 to August 2010 and followed up the patients until September 2011. The changes in LV function parameters before and after the treatment were evaluated by echocardiography. Results The mean age at the start of treatment with enalapril or carvedilol was 12.6±3.7 years (median 13 years), and mean follow-up duration was 20.1±8.9 months. In the enalapril group, LV fractional shortening (FS) increased from 25.8±2.1 to 26.6±3.0 (p=0.241). In the carvedilol group, LV FS increased from 26.4±1.1 to 28.6±4.2 (p=0.110). In all 23 patients, LV FS significantly increased from 26.1±1.7 (before) to 27.6±3.7 (after treatment) (p

Background and Objectives: Pulmonary arterial hypertension (PAH) is a rare disease with a poor prognosis. The aim of this study was to characterize PAH in pediatric patients by evaluating the patients demographics, clinical and hemodynamic variables, treatments, and outcomes. Subjects and Methods: Sixty-five patients who were diagnosed with PAH at Seoul National University Children’s Hospital between January 1985 and August 2007 were retrospectively reviewed. Results: There was no difference in gender distribution (males, 33; females, 32). The mean age at the time of diagnosis was 5.7±5.2 years and the mean follow-up period was 6.3±5.5 years. The major causes of PAH were congenital heart disease (CHD) in 32 patients (49.2%) and idiopathic PAH in 11 patients (16.9%). The most common presenting symptom was dyspnea in 44 patients (67.7%). The mean cardiothoracic ratio was 58.9±8.3%, which decreased to 55.9±8.3% after vasodilator therapy (p=0.011). The mean pulmonary arterial pressure at the time of cardiac catheterization was 59.7±18.7 mmHg and the mean pulmonary vascular resistance was 14.9±9.7 wood units·m. Forty-three of 65 patients (66.2%) had vasodilator therapy (prostacycline, sildenafil, and bosentan). A statistically significant decrease in tricuspid valve regurgitation velocity (4.8±0.8 m/sec vs. 3.6±1.0 m/sec, p=0.001), and an increase in diastolic dimension of the left ventricle (28.3 ±12.1 mm vs. 33.2±10.2 mm, p=0.021) on echocardiography before and after vasodilator therapy was demonstrated. The 5-, 10-, and 15-year survival rates were 96%, 92% and 65%, respectively. Six of 65 patients (9.2%) with PAH died. There was no significant correlation between outcome and the immediate response to the vasodilators. Conclusion: PAH is a devastating disease which is rare in children. PAH in children has a variable pattern cause and progression, the confirmation of which requires analysis of detailed registries from nationwide hospitals. (Korean Circ J 2008;38:644-650)

Background and Objectives: This study aimed to evaluate the usefulness of cardiopulmonary exercise test (CPET) in children with various congenital heart diseases (CHDs). Subjects and Methods: Forty-eight children and adolescents (18 girls and 30 boys; mean±SD age, 12.6±0.5 years) with CHD who had undergone corrective surgery performed CPET using a programmable treadmill. The participants were divided into 4 groups based on the surgery performed: Fontan operation (12 patients), total correction for tetralogy of Fallot (13 patients), repair for coarctation of aorta (11 patients), and corrective surgery for simple CHDs (12 patients). Patients with simple CHDs who had undergone an early surgery were selected as controls. Results: Progressive exercise time was the longest in the simple CHD group than in the other groups (10.6±2 versus 8.2-8.7 min, p=0.122). Absolute and predicted values of mean peak oxygen consumption were the lowest in the Fontan operation group (p=0.220 and 0.091, respectively). The coarctation of aorta group exhibited a prominent blood pressure response, that is, an elevation in the systolic blood pressure relative to that in the other groups at rest (131.7±18.8 versus 114.4121.3 mmHg) and at peak exercise (196.5±41.5 versus 146.8-184.3 mmHg). Conclusion: CPET can be a useful tool to clarify the exercise capacity and reflect the hemodynamic status of patients who have undergone surgery for various CHDs and other heart diseases. (Korean Circulation J 2007;37:489-496)

Background and Objectives: The relative proportion of infective endocarditis (IE) with congenital heart disease (CHD) has increased because of improved survival with CHD. This may affect the current profile of IE with CHD. The aim of this study is to assess the changing profiles of IE with CHD. Subjects and Methods: All cases diagnosed from January 1985 to May 2006 were retrospectively reviewed and were analyzed according to the diagnosed period (period I-prior to 1995, period II-after 1996). Duke criteria were used for the definition of diagnosis. Results: As a whole, 121 episodes occurred (63 episodes in period I and 58 episodes in period II). Although the mean age was similar for patients diagnosed in the two periods, the proportion of younger age patients was larger during period II. During period II, the number of non-surgical ventricular septal defect (VSD) cases decreased and the number of Rastelli procedure cases increased. Negative blood cultures were similar in patients for both periods. S. viridans was the most common causative organism in patients during both periods. Post-surgical cases and IE after a dental procedure increased during period II. The in-hospital mortality rate, total complication rate, and proportion of IE requiring early surgery were not different for patients in either period. However, the interval to early surgery was shorter for patients during period II (period I 35±21.1 days, period II 22±16.5 days, p=0.041). Conclusion: Our study indicates that IE in CHD is still a major problem with similar clinical features exhibited during the two different periods. The presence of non-surgical VSD as a major underlying defect indicates that one needs to pay more attention to the education of the population at risk. (Korean Circ J 2007;37:635-640)

Background and Objectives:Based on our previous studies on pulmonary atresia with ventricular septal defect (VSD) and major aorto-pulmonary collateral arteries (MAPCAs), a management strategy for this disease was formulated at our hospital in 1999. To evaluate this strategy, it was applied to the new patients and their outcomes were measured. Subjects and Methods:The subjects were a cohort of newly diagnosed patients who were without any prior interventions and these patients were treated at our hospital from January 2000 to December 2003. The management strategy focused on promoting the growth of the pulmonary arterial confluence (PAC), if present, by performing a right ventricle-pulmonary artery conduit operation (RV-PA conduit). If the PAC was large or absent, then the management plan was discussed among the surgeons after performing an exhaustive work-up. Results:Seventeen patients were enrolled and their age at the time of diagnosis ranged from 8 days to 34 months with a median age of 3 months. The initial surgical method varied from one-stage total correction (4 cases) to a conduit operation with or without additional MAPCAs procedures (13 cases). All but three of the patients survived their initial surgery. There were two late deaths. In addition to the 3 survivors from one-stage total correction, 4 patients underwent a staged total corrective operation. The 5 remaining patients are still a subtotal correction state or a palliated state. Conclusion:When a large PAC is present, one-stage total correction is the best surgical option. However, when the PAC is small, then RV-PA conduit without any vascular procedures may be a good alternative. This staged approach makes a larger PAC, which enables surgeons to create a much easier vascular anastomosis later on. (Korean Circulation J 2007;37:348-352)

Background and Objectives:Cardiovascular morbidities and mortalities due to persistent hypertension, left ventricular (LV) dysfunction and increased LV mass have been reported in adolescents and adults with successful coarctoplasty. We evaluated progressive properties by measuring resting blood pressures (BP), LV functions and the masses in young children with successful coarctoplasty in infancy. Subjects and Methods: BP in the right arm and the left ankle, LV function and mass, by the use of M-mode and pulsed wave Doppler ultrasound, were measured in 25 patients, with a mean age of 6.4±3 years;and a mean age at the time of repair of 0.22±0.24 years, and in 22 control subjects, with a mean age of 5.8±2.4 years. All subjects were divided into two groups based on age (more than 5 years of age and less than 5 years of age) and were analyzed independently. Results:BP in the right arm and left ankle, LV function and mass showed no consistent differences between the two groups. However, as age increased, there was a tendency of wide pulse pressure (PP) in the right arm of patients contrary to that in the control subjects. The relative increase in the PP was mainly due to a relative decrease in the diastolic BP. There was a significant increase in the LV mass index of patients with increasing age (p

Background and Objectives:Idiopathic restrictive cardiomyopathy is a very rare and poorly recognized disease in children. This study was performed in order to describe the clinical course and to define potential predictors of outcome. Material and Method:We reviewed the medical records and diagnostic studies of 11 consecutive patients during the period from Jan. 1991 to Aug. 2000. Results:The age at diagnosis was 1.213 years (median 7 years) and the duration of follow up was 3-90 months (median 3.6 years). With the exception of one patient, all were symptomatic (dyspnea in ten, chest pain in four). The chest pain was associated with significant ST depression on both resting and exercise ECG, suggesting myocardial ischemia. Two patients demonstrated complete heart block as either an initial or terminal event. Cardiac catheterization was done in nine patients (mean pulmonary arterial wedge pressure 23±6 mmHg, systolic pulmonary arterial pressure 47 ±14 mmHg, mean right atrial pressure 11±9 mmHg). The echocardiographic dimensional ratio of the left atrium and aorta (LA/Ao) was 2.41±0.58. The mitral E/A inflow ratio was 2.72±1.42, E wave deceleration time was 93.6±44.2 ms. During follow up, six patients died. The 2-year and 5-year cumulative survival rates were 54.5% and 18.8% respectively. The predictors for nonsurvivor were pulmonary venous congestion and LA/Ao>2.5 (p 2.5) were at risk for death, requiring prompt definitive treatment such as cardiac transplantation. (Korean Circulation J 2001;31(4):427-433)

Background:Although idiopathic cardiomyopathies (i-CMP are very important in all age groups, the epidemiology of i-CMP in children has not been well defined. A retrospective study in Korean children was performed in 1998 to obtain basic data on i-CMP. Material and Method:The medical records of all patients aged birth to 15 years from the hospitals where pediatric cardiologists worked were reviewed to obtain information on i-CMP. Pediatric cardiologists from a total of 22 hospitals were participated in reviewing the medical records of their patients and filling up the protocol. The data were pooled to the study committee and reviewed. Results:Of the 278 cases with i-CMP, there were dilated cardiomyopathy (d-CMP in 182 (65.4%; hypertrophic cardiomyopathy (h-CMP in 74 (26.6%; restrictive cardiomyopathy (r-CMP and unclassified in 17 (6.1% and 5 (1.9% each. The average annual occurrence of new cases as a whole was 2.65 per 100,000 (95% CI ; 1.5-3.7; d-CMP, 1.73/100,000/year (95% CI ; 0.73-2.73; h-CMP, 0.71/100,000/year (95% CI;0.35-1.07; r-CMP, 0.16/100,000/year (95% CI;0.02-0.3. The median age at the time of diagnosis was 11 months in d-CMP;3.0 years in h-CMP;6.9 years in r-CMP. The survival rate in d-CMP was 76% at 1 year, 72.5% at 2 year, 70% at 5 year. There was no difference in survival rate according to age (in d-CMP, between children less than 2 years of age and over 2 years of age (74% vs. 79% at 1 year;67% vs. 76% at 5 year, p=NS: in h-CMP, between children less than 1 year of age and over 1 year of age (84% vs. 96% at 1 year;63% vs. 81% at 5 year, p=NS. R-CMP showed the worst survival rate (72% at 1 year, 30.2% at 5 year. Conclusion:In spite of the inherent defects of retrospective analysis, this study provides the useful epidemiological data in children with i-CMP. However, more systemic approach is needed to define the nature of the i-CMP in children. (Korean Circulation J 2000;30(5 :635-645

Purpose:Catecholaminergic polymorphic ventricular tachycardia (CPVT) is the disease entity of adrenergic dependent, potentially lethal tachyarrhythmia in a child with no structural heart disease, which manifest itself as a syncope or sudden death. The objective of this study is to present our experiences on this important, although rare, disease. Methods:Retrospective analysis of 5 patients with episodes of syncope related to exercise, who were referred to our hospital from January 1985 to December 1998. Results:All patients were male and the mean age at the time of the first syncopal episode was 5.1±3.2 years (range 1.3 to 10 years). There were no structural cardiac abnormalities in clinical and laboratory evaluations. In all, polymorphic ventricular tachycardia showing the characteristic pattern of CPVT in which, as the heart became stimulated adrenergically, isolated ventricular premature beats appeared, increased with rate, became polymorphic, finally formed burst with bidirectional salvoes and disappeared in resting state was induced during exercise test and/or isoproterenol infusion test. During the mean follow up period of 3.75±3.1 years (range 1 month to 7.3 years), one died suddenly. In this case, low dose of β-blocker was administered because of associated sinus bradycardia resulting in incomplete control of the syncopal episodes. The other 4 cases were alive and asymptomatic by means of adequate modification of β-blocker dosage and method of administration. Conclusions:This study emphasizes that CPVT is an important, although rare, cause of exercise related syncope in children and can be diagnosed by means of exercise test and/or isoproterenol infusion. β-blockers were very effective in all cases, even though increasing amount of β-blocker was frequently necessary to control ventricular arrhythmia in some cases. (Korean Circulation J 2000;30(2):191-197)

Clinical Features and Molecular Diagnosis of CATCH-22 Syndrome Jung Yun Choi, MD1,2, Jeong-Wook Seo, MD1,3, Myoung Hee Kim, PhD4, Eul Kyung Kim, MD3, Jung-Sun Kim, MD3, Ho Sung Kim, MD2, Chong Heon Lee, DDS3, Hyangsuk Hur, PhD4, Eun Jung Bae, MD5, Chung IL Noh, MD1,2 and Yong Soo Yun, MD1,2 Heart Research Institute, Medical Research Center, Seoul National University, Seoul, Departments of Pediatrics and Pathology, Seoul National University College of Medicine, Seoul, Korea Research Institute of Bioscience and Biotechnology, KIST, Taejon, Department of Pediatrics, Sejong General Hospital, Buchon, Kyunggi-do, Korea

Background:Ebstein's anomaly is characterized by various degrees of apical displacement of the proximal attachment of the tricuspid valve. The disease has an extremely variable course in presenting itself. Therefore, we examined the morphologic and clinical features of Ebstein's anomaly as presented in the fetus to define the factors that determine its outcome. Methods:We reviewed the history and echocardiographic studies of 10 fetuses(mean gestational age 28.0 weeks diagnosed in utero with Ebstein's anomaly. The reason for referral was cardiomegaly on routine obstetric scanning in 5 cases, fetal arrhythmia in 3 cases, small main pulmonary artery in 3 cases, vessel view in 1, and twin pregnancy complicated by polyhydramniosis in 1. Results:Of the 10 cases, pregnancy was terminated after diagnosis in 5, 2 cases were carried to term, and 1 case was at 34 weeks of gestation. We were unable to follow-up 2 cases. There were no intrauterine deaths and no misdiagnoses. Massive cardiomegaly and severe tricuspid regurgitation were detected in 7 cases; mild cases were detected in two, and one was nearly normal. Associated cardiac lesions included pulmonary artresia in 4 cases, pulmonary stenosis in 3, and pulmonary hypoplasia in 1. The cases with right ventricular outflow tract(RVOT obstruction showed a tendency to develop more cardiomegaly and tricuspid regurgitation than with normal RVOT. There was no abnormality in other organ systems and karyotyping. Conclusion:Although increased cardiothoracic ratio and associated lesions of the right ven- ricular outflow tract contribute to the poor outcome in the prenatally detected cases, the absence of

Background:Idiopathic left ventricular tachycardia with a QRS pattern of right bundle branch block and left axis deviation that is sensitive to verapamil is electrophysiologically distinct arrhythmia entity but descriptions in pediatric ages are infrequent. This study attempted to describe the clinical presentation and diagnostic clues from the surface ECG in children with idiopathic left ventricular tachycardia. Methods:We retrospectively reviewed the medical records, electrocardiograms, Holter recordings, echocardiographic reports of 10 children with idiopathic left ventricular tachycardia who have been managed at Sejong General Hospital and Asan Medical Center, Seoul, Korea from January 1991 to July 1996. Follow-up periods are 2 months to 5 years(mean=26 months. Results: 1 Age of tachycardia onset was 8 months to 14 years(median=4.3 years. In 3 children tachycardia began from infancy. The main complaint in older children was palpitation and chest discomfort but young children complained abdominal pain during tachycardia attack. Tachycardia was paroxysmal and sustained. Tachycardia responded to intravenous use of verapamil in 9 patients and was controlled by chronic verapamil medication in 6 patients. 2 patients were well without medication. Radiofrequ- ency catheter ablation was done in an adolescent patient successfully. 2 In sinus rhythm, surface ECG showed normal QRS axis and normal QRS morphologies in all patients. During ventricular tachycardia, the heart rate was 183 to 270 beats/min. The tachycardia of RBBB morphology was observed in all patients. The mean QRS duration was 109±12ms and the QRS axis was -50° to -90° . The mean RS interval was 60±12ms. AV dissociation was found on surface ECG in all patients and confirmed in 4 patients by transesophageal ECG. We tried rapid tran- sesophageal atrial pacing in 3 patients and could induce and terminate the ventricular tachycardia. Conclusions:Idiopathic left ventricular tachycardia is rare in childhood and is seen from infancy. Idiopathic left ventricular tachycardia is generally benign but occasionally causes myocardial dysfun- ction. Idiopathic ventricular tachycardia with a QRS pattern of right bundle branch block and left axis