Bo Sang Kwon

Pulmonary hypertension in preterm infants with bronchopulmonary dysplasia.

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 <800 g, long-term ventilator care and oxygen supplementation, a high ventilator setting, infection, and a patent ductus arteriosus (PDA) were related to PH based on univariate analysis (p<0.05). The infants who had longer oxygen supplementation were significantly more likely to have PH (odds ratio, 18.5; 95% confidence interval, 4.1-84.6; p<0.001). PH was improved in 76% of infants after a median of 85 days (range, 20-765 days). Four infants (14%) died. The death of 3 infants was attributed to PH. Conclusion BPD was frequently complicated by PH. Although PH resolved in the majority of infants, PH in preterm infants with BPD can be fatal. Regular screening for PH and adequate management are required.

The mental health and quality of life of adult patients with congenital heart disease

BACKGROUND The quality of life (QoL) of adults with congenital heart disease (CHD) has gained significant interest. In addition to medical problems, many patients with CHD face psychosocial, educational, and behavioral challenges. However, few studies have examined the relationship between disease severity and QoL in adults with CHD. METHODS Eighty-five patients (50 men, 35 women) aged 20-52 years (median, 26.5 years) were enrolled. Patients underwent a QoL, Beck Depression Inventory (BDI), and Beck Anxiety Inventory (BAI) survey. The scores were compared with those of age- and gender-matched population data according to the degree of underlying CHD. Disease severity was classified in relation to initial diagnosis, illness course, and current functional status (New York Heart Association [NYHA] class, ability index, CHD functional index, ventricular ejection fraction, and peak VO2). RESULTS There was no significant correlation between disease severity and current functional status assessed by BDI and BAI. Patients who stated that they were religious had better scores for resilience (p=0.031), physical QoL (p=0.008), and environmental QoL (p=0.025). Environmental QoL scores were higher in patients who fully understood their disease (p=0.004). Current NYHA functional class was associated with scores for psychological resilience. CONCLUSIONS CHD severity had a detrimental impact on resilience only when measured in terms of poor functional status. The initial diagnosis and course of the illness influence QoL and perceived health. Good psychosocial adaptation could be the result of close family relationships and involvement, making mental adjustment easier.

Intra-atrial reentrant tachycardia in adult patients after Fontan operation

BACKGROUND Atrial tachyarrhythmia is a major late complication in adult Fontan patients. This study examined the clinical features and risk factors of late intra-atrial reentrant tachyarrhythmia (IART) in adult patients after Fontan surgery and the mid-term outcome of Fontan conversion with or without antiarrhythmic surgery in these patients. METHODS We conducted a retrospective study on adult patients who were born before 1994 and survived at least 3 months after a Fontan operation at Seoul National University Childrens Hospital. RESULTS We followed 160 patients over 20.9 ± 4.1 years. Sustained atrial tachycardia was identified in 51 patients, and IART was found in 41, appearing a mean 13.6 years after surgery. By the 25 year follow-up, 40% had developed IART. The incidence of IART significantly increased over time. Patients with an atriopulmonary connection (APC) (n=65) had significantly longer follow-up duration and higher incidence of IART than patients with a lateral tunnel (n=86) or extracardiac conduit Fontan (n=9). On multivariate analysis, APC, sinus node dysfunction, and nonsustained atrial tachycardia were found to be significantly associated with IART. Twenty-four patients with IART underwent Fontan conversion. Over the follow-up period, IART severity scores in the 22 patients who survived after Fontan conversion decreased significantly, and New York Heart Association functional class significantly improved. On multivariate analysis, protein losing enteropathy and ventricular dysfunction were found to be significant risk factors for mortality. CONCLUSIONS IART was common in adult Fontan patients, and Fontan conversion with or without antiarrhythmic surgery and pacemaker placement helped to control it.

Clinical Course of Vascular Rings and Risk Factors Associated With Mortality

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 National University Childrens 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 eventually 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.

The Effect of Enalapril and Carvedilol on Left Ventricular Dysfunction in Middle Childhood and Adolescent Patients With Muscular Dystrophy

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<0.046). Indexed LV dimension at end diastole and LV end-diastolic volume decreased slightly, but without statistical significance by tri-plane volumetry. LV diastolic functional parameters were maintained during follow-up period. Conclusion Enalapril or carvedilol could improve LV systolic function in middle childhood and adolescent patients with muscular dystrophy without significant adverse effects.

Pediatric emergency room presentation of congenital heart disease.

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.

The mid-term surgical results of Fontan conversion with antiarrhythmia surgery

OBJECTIVES We investigated the mid-term surgical results of Fontan conversion with antiarrhythmias surgery and permanent pacemaker implantation, which were complications of a previous Fontan operation. METHODS From January 1996 to November 2011, we performed Fontan conversion in 31 of 260 Fontan cases (M:F = 17:14, mean age = 19.0 years). The Fontan conversion from atriopulmonary connection (APC) to extracardiac conduit (ECC) was performed in 20 patients, APC to lateral tunnel in 5 and lateral tunnel to ECC in 6. The clinical outcomes and improvements of arrhythmias were analysed. The types of arrhythmias included atrial flutter in 21 patients, atrial fibrillation with flutter in 4 patients and junctional tachycardia in 3 patients. RESULTS Twenty-six patients (83.9%) required antiarrhythmia surgery (isthmus cryoablation = 9, right-sided maze = 13, bilateral maze = 4). In addition, 23 patients (74.2%) received a permanent pacemaker. The New York Heart Association functional class (NYHA Fc) was statistically improved after the surgery during the 6.5-year median follow-up duration (preoperative NYHA Fc = 1.77, postoperative NYHA Fc = 1.13, n = 15, P = 0.001). There were 4 late mortalities. Actuarial 5-year survival was 90.0 ± 5.5%. And freedom from arrhythmia was 91.8 ± 5.5%, at 5 years. Normal sinus rhythm was maintained in 12 patients (38.7%), pacing-dependent rhythm in 10 patients (32.3%) and intermittent pacing-dependent rhythm in 4 patients (12.9%). CONCLUSIONS Fontan conversion with antiarrhythmia surgery and permanent pacemaker implantation is safe and improves the clinical outcome and arrhythmias.

Incidence, risk factors and clinical outcomes for acute kidney injury after aortic arch repair in paediatric patients

OBJECTIVES Acute kidney injury (AKI) is common after paediatric cardiac surgery and associated with increased morbidity and mortality. Aortic arch surgery may be an independent risk factor for AKI because of circulatory arrest below the descending thoracic artery during anastomosis. We investigated the surgical outcomes associated with AKI after aortic arch repair in paediatric patients. METHODS We retrospectively analysed 120 paediatric patients who underwent aortic arch repair between 2003 and 2012. AKI was defined according to the paediatric-modified risk, injury, failure, loss and end-stage kidney disease criteria. The incidence, clinical outcomes and risk factors for AKI were analysed. RESULTS Aortic arch repair was performed for coarctation of aorta in 97 patients and interrupted aortic arch in 23 patients. The median age and body weight at the time of surgery were 16.5 days and 3.3 kg, respectively. The mean duration of the follow-up was 3.9 years. AKI developed in 42 patients (36.8%) and peritoneal dialysis (PD) was applied in 20 patients (16.7%). The recovery of renal function began a mean of 3.8 days after conservative management, and full recovery occurred a mean of 6.7 days after conservative management. A lower body weight (<3.0 kg) (odds ratio [OR]: 7.569, P = 0.009) and the absence of prerenal impairment (OR: 9.876, P = 0.041) were shown to be independent risk factors. Patients who required PD had prolonged intensive care unit and hospital stays (P = 0.002 and P = 0.003). CONCLUSIONS AKI is common in low-birth-weight patients after aortic arch repair surgery. However, patients recover from AKI after conservative management. Requiring PD increases the morbidity associated with AKI.

Radiofrequency Catheter Ablation for Supraventricular Tachycardia: A Comparison Study of Children Aged 0–4 and 5–9 Years

The safety and effectiveness of radiofrequency catheter ablation (RFCA) for supraventricular tachycardia (SVT) in young children was investigated.

Alagille syndrome and a JAG1 mutation: 41 cases of experience at a single center

Purpose Alagille syndrome is a complex hereditary disorder that is associated with cardiac, hepatic, skeletal, ocular, and facial abnormalities. Mutations in the Notch signaling pathway, such as in JAG1 and NOTCH2, play a key role in embryonic development. A cardiac or hepatic presentation is a critical factor for determining the prognosis. Methods We conducted a retrospective study of 41 patients with Alagille syndrome or a JAG1 mutation between 1983 and 2013. Results The first presentations were jaundice, murmur, cyanosis, and small bowel obstruction at a median age of 1.0 months (range, 0-24 months). The JAG1 mutation was found in 27 of the 28 genetically-tested patients. Cardiovascular anomalies were identified in 36 patients, chronic cholestasis was identified in 34, and liver transplantation was performed in 9. There was no significant correlation between the severity of the liver and cardiac diseases. The most common cardiovascular anomaly was peripheral pulmonary stenosis (83.3%), with 13 patients having significant hemodynamic derangement and 12 undergoing surgical repair. A total bilirubin level of >15 mg/dL with a complex surgical procedure increased the surgical mortality (P=0.022). Eight patients died after a median period of 2.67 years (range, 0.33-15 years). The groups with fetal presentation and with combined severe liver and heart disease had the poorest survival (P<0.001). Conclusion The group with combined severe liver and heart disease had the poorest survival, and a multidisciplinary approach is necessary to improve the outcome.