Treatment of Primary Cardiac Tumors in Children: A Single Center 18-Year Experience.

This study aimed to compare the clinical characteristics and courses of pediatric patients with cardiac tumors in nonoperative and operative groups to help guide treatment decisions. We reviewed the medical records of patients diagnosed with primary pediatric cardiac tumors at our institution between 2003 and 2020. Demographic data, clinical characteristics, and follow-up data between the operation and nonoperation groups were compared. A total of 56 patients were included in the study. Thirteen patients underwent surgery. The median age was 1.4 months (range, 1 to 18 years). The patients in the operation group had more frequent symptoms or signs, such as desaturation, respiratory difficulty, murmur, a higher mass area/chamber area (MC) ratio, decreased ventricular contractility, and significant ventricular outflow tract obstruction (VOTO). An MC ratio of 0.568 was the cutoff value for differentiating patients with symptoms or signs of heart failure and decreased ventricular contractility. At the last follow-up, all patients had good ventricular contractility except one patient in the operative group with fibroma. In the non-operative group, rhabdomyomas often regressed spontaneously, while fibromas often increased in size. Two patients in the nonoperative group died. In the operative group, there was no early or late mortality or tumor recurrence. In this study, patients had good outcomes with or without surgery, even when the tumor was large, or surgery was performed in early infancy.

Long-Term Outcomes of Modified Cone Reconstruction for Ebstein's Anomaly in Pediatric Patients in a Single Center.

BACKGROUND AND OBJECTIVE: We aimed to investigate long-term clinical and echocardiographic outcomes, including tricuspid valve durability, annular growth, and left ventricular reverse remodeling, after modified cone reconstruction in patients with Ebstein's anomaly. METHODS: This was a retrospective analysis of all pediatric patients who underwent modified cone reconstruction for Ebstein's anomaly at a single tertiary center between January 2005 and June 2021. RESULTS: A total of 14 pediatric patients underwent modified cone reconstruction for Ebstein's anomaly; the median age was 5.8 years (range, 0.01-16.6). There were three patients (21.4%) with Carpentier type B, ten patients with Carpentier type C (71.4%), and one patient with Carpentier type D (7.1%). There was no early or late mortality, arrhythmia, or readmission for heart failure at a 10-year follow-up. There were no cases of more than mild tricuspid stenosis or more than moderate tricuspid regurgitation during the study period, except for one patient with severe tricuspid regurgitation who underwent reoperation. The z value for tricuspid valve annular size significantly decreased immediately after the operation (2.46 vs. -1.15, p<0.001). However, from 1 year to 7 years after surgery, the z values were maintained between -1 and +1. Left ventricular end-systolic volume, end-diastolic volume, and stroke volume increased after surgery and remained elevated until seven years postoperatively. CONCLUSIONS: Ebstein's anomaly in children can be repaired by modified cone reconstruction with low mortality and morbidity, good tricuspid valve durability, and annular growth relative to somatic growth.

Ecotoxicity of polylactic acid microplastic fragments to Daphnia magna and the effect of ultraviolet weathering.

Biodegradable plastics (BPs) are widely used as alternatives to non-BPs due to their inherent ability to undergo facile degradation. However, the ecotoxicological impact of biodegradable microplastics (MPs) rarely remains scientific documented especially to aquatic ecosystem and organisms compared to conventional microplastics. Therefore, this study aimed to investigate the ecotoxicity of biodegradable polylactic acid (PLA) MPs to Daphnia magna with that of conventional polyethylene (PE) MPs with and without ultraviolet (UV) treatment (4 weeks). The acute toxicity (48 h) of PLA MPs was significantly higher than that of PE MPs, potentially attributable to their elevated bioconcentration resulting from their higher density. UV treatment notably reduced the particle size of PLA MPs and induced new hydrophilic functional groups containing oxygen. Thus, the acute lethal toxicity of PLA MPs exhibited noteworthy increase, compared to before UV treatment after UV treatment, which was greater than that of UV-PE MPs. In addition, UV-PLA MPs showed markedly elevated reactive oxygen species concentration in D. magna compared to positive control. However, there was no significant increase in the level of lipid peroxidation, possibly due to successful defense by antioxidant enzymes (superoxide dismutase and catalase). These findings highlight the ecotoxicological risks of biodegradable MPs to aquatic organisms, which require comprehensive long-term studies.

Chronic toxicity of biodegradable microplastic (Polylactic acid) to Daphnia magna: A comparison with polyethylene terephthalate.

The increase in the usage of biodegradable microplastics (MPs) as an alternative to conventional plastics has necessitated comprehensive ecotoxicity assessments of biodegradable MPs alongside conventional MPs. This study aimed to assess ecotoxicity of biodegradable polylactic acid (PLA) MPs at concentration of 1 and 5 mgL-1 including a genetic analysis of Daphnia magna, and compared to effects of conventional polyethylene terephthalate (PET) MPs. The survival rate for D. magna exposed to 5 mg L-1 of PLA-MPs declined to 52.4 %, signifying a higher rate of mortality when contrasted with PET-MPs, which exhibited 85.7 % survival rate. Chronic exposure to 1 and 5 mgL-1 PLA-MPs resulted in a decrease of offspring, while increasing the sex ratio and deformed embryo. Interestingly, down-regulation of the SOD and AK genes was observed in D. magna after exposure to 5 mgL-1 of PLA-MPs, while 1 mgL-1 of PLA-MPs up-regulated. These results means that 5 mgL-1 PLA-MP could not produce energy and cope with oxidative stress, resulting in high mortality, and 1 mgL-1 of MP was maintained survival due to energy production and antioxidant action. This study contributes to our understanding of biodegradable microplastics (BMPs) toxic effects on D. magna which could be similar to conventional MPs and provide the importance of ecotoxicological data for risk assessment of BMPs in aquatic organisms.

Prognosis of Chronic Kidney Disease and Metabolic Syndrome in Adults With Congenital Heart Disease.

BACKGROUND: Few studies have examined the incidence of chronic kidney disease (CKD) and metabolic syndrome (MS) and their combined prognostic effects in adult congenital heart disease (ACHD). Our aims were to identify the incidence and prognostic implications of CKD and MS in ACHD. METHODS: This is retrospective cohort study. We included 2,462 ACHD ≥ 20 years of age who were treated at a tertiary hospital in Korea from 2006 to 2018. CKD was defined as an estimated glomerular filtration rate < 60 mL/min/1.73m². MS was diagnosed based on the presence of abnormal metabolic parameters: blood sugar level, obesity, dyslipidemia, and hypertension. The primary outcome was all-cause mortality from 2006 through 2019 using data from the Ministry of the Interior and Safety in Korea. RESULTS: The incidence of CKD and MS in ACHD was 7.6% and 35.9%, respectively. The coexistence rate of CKD and MS was 4.6%. Although MS was not independently associated with mortality in the multiple analysis (adjusted hazard ratio [aHR], 1.07; 95% confidence interval [CI], 0.79-1.46), it was closely related to the presence of CKD (adjusted odds ratio, 2.62; 95% CI, 1.89-3.63). ACHD patients with CKD had a significantly increased risk of mortality compared with those without CKD (aHR, 2.84; 95% CI, 2.00-4.04). CONCLUSIONS: In patients with ACHD, the distribution of MS is higher, and both MS and its components were associated with CKD. Given the CKD was independently associated with mortality, close monitoring and management of renal dysfunction and metabolic parameters in ACHD patients is needed.

Elevated temperature enhanced lethal and sublethal acute toxicity of polyethylene microplastic fragments in Daphnia magna.

Microplastic (MP) pollution poses a growing concern in freshwater ecosystems, which are further threatened by global warming. Thus, this study investigated the effect of elevated temperature (25 °C) on acute toxicity of polyethylene MP fragments to Daphnia magna over a 48 h period. At the reference temperature (20 °C), MP fragments (41.88 ± 5.71 µm) induced over 70 times higher lethal toxicity than that induced by MP beads (44.50 ± 2.50 µm), with median effective concentrations (EC50) of 3.89 and 275.89 mg L-1, respectively. Elevated temperature significantly increased (p < 0.05) the lethal (EC50 = 1.88 mg L-1) and sublethal (lipid peroxidation and total antioxidant capacity) toxicity in D. magna exposed to MP fragments compared to those at the reference temperature. Additionally, the elevated temperature led to a significant increase (p < 0.05) in the bioconcentration of MP fragments in D. magna. Overall, the present study increases understanding for the ecological risk assessment of microplastics under global warming, highlights that elevated temperature can be seriously increased bioconcentration of MP fragments, leading to increased acute toxicity in D. magna.

Percutaneous Transcatheter Closure of Congenital Ventricular Septal Defects.

Ventricular septal defects (VSDs) are the most common kind of congenital heart disease and, if indicated, surgical closure has been accepted as a gold-standard treatment. However, as less-invasive methods are preferred, percutaneous device closure has been developed. After the first VSD closure was performed percutaneously by Lock in 1988, both techniques and devices have developed consistently. A perventricular approach for closure of muscular VSD in small patients and the closure of perimembranous VSD using off-label devices are key remarkable developments. Even though the Amplatzer membranous VSD occluder (Abbott) could not be approved for use due to the high complete atrioventricular conduction block rate, other new devices have shown good results for closure of perimembranous VSDs. However, the transcatheter technique is slightly complicated to perform, and concerns about conduction problems after VSD closure with devices remain. There have been a few reports demonstrating successful closure of subarterial-type VSDs with Amplatzer devices, but long-term issues involving aortic valve damage have not been explored yet. In conclusion, transcatheter VSD closure should be accepted as being as effective and safe as surgery but should only be performed by experienced persons and in specialized institutes because the procedure is complex and requires different techniques. To avoid serious complications, identifying appropriate patient candidates for device closure before the procedure is very important.

Maternal Effect of Polyethylene Microplastic Fragments Containing Benzophenone-3 in Different Ages and Broods of Daphnia Magna.

The maternal effect of microplastics (MPs) toxicity is likely influenced by age and brood of test species. This study investigated the maternal effect of polyethylene MP fragments (18.23 ± 8.02 µm) with benzophenone-3 (BP-3; 2.89 ± 0.20% w/w) on chronic toxicity to Daphnia magna over two generations. Neonate (< 24 h old) and adult (5 d old) daphnids in the F0 generation were exposed until 21 d old, then first and third brood neonates in the F1 generation were recovered in clean M4 medium for 21 d. Higher chronic toxicity and maternal effect of MP/BP-3 fragments were observed in the adult group compared with the neonate group, reducing growth and reproduction in both F0 and F1 generations. First brood neonates in the F1 generation showed a higher maternal effect of MP/BP-3 fragments than third brood ones, resulting in enhanced growth and reproduction relative to the control. This study provided insights into the ecological risk of MPs containing plastic additives in the natural environment.

Effects of time of bed rest on vascular complications after cardiac catheterization in pediatric patients with congenital heart disease: A randomized controlled trial.

BACKGROUND: Pediatric cardiac catheterization, which is performed by accessing the femoral vessel, requires immobilization and bed rest for 4-6 h to prevent vascular complications. Studies in adults suggest that the immobilization time for the same access can be safely reduced to approximately 2 h after catheterization. However, it is unclear whether bed-rest time can be safely decreased after catheterization in children. OBJECTIVE: To assess the effects of bed-rest duration on bleeding, vascular complications, pain level, and the use of additional sedatives after transfemoral cardiac catheterization in children with congenital heart disease. METHODS: This study was an open-label, randomized, controlled, posttest-only design, including 86 children who underwent cardiac catheterization. Children were allocated to receive either 2 h of bed rest (n = 42) in the experimental group or 4 h of bed rest (n = 42) in the control group following catheterization. RESULTS: The mean age of children was 3.93 (±3.82) years in the experimental group and 5.63 (±3.97) years in the control group. There was no difference in site bleeding incidence (P = 0.214), vascular complication score (P = 0.082), pain level (P = 0.445), or additional sedation use (P = 1.000) between the two groups. CONCLUSIONS: There were no significant hemostatic complications after 2 h of bed rest following pediatric catheterization; therefore, 2 h of bed rest was as safe as 4 h of bed rest. (Trial registration: KCT0007737).

The effects of music intervention on anxiety and stress responses in adults with CHD undergoing cardiac catheterisation.

INTRODUCTION: This study evaluated the effect of music intervention on the anxiety and stress responses of patients who underwent an interventional cardiac catheterisation. METHODS: The study design was a pre- and post-test randomised controlled trial that included 94 patients who underwent a transcatheter atrial septal defect closure. Patients were allocated to receive either music intervention (n = 47) or usual care (n = 47) during the interventional cardiac catheterisation. Music intervention effectiveness was examined in terms of anxiety, salivary cortisol level, and heart rate variability. RESULTS: The average age of participants was 45.40 years (±16.04) in the experimental group and 47.26 years (±13.83) in the control group. Two-thirds (66.0%) of the participants in each group were women. State anxiety (F = 31.42, p < 0.001), anxiety-numerical rating scale (F = 20.08, p < 0.001), salivary cortisol levels (F = 4.98, p = 0.021), and low-frequency component/high-frequency component ratio (F = 17.31, p < 0.001) in the experimental group were significantly reduced compared with those in the control group at the end of the music intervention. CONCLUSION: This study provides practical evidence of a reduction in anxiety and stress response from music intervention preceding an interventional cardiac catheterisation, indicating that this intervention should be considered in clinical management.

Severe headache in a middle-aged woman after device closure of a ventricular septal defect.

Reversible cerebral vasoconstriction syndrome presents with thunderclap headache and represents a group of conditions that show reversible multifocal narrowing of cerebral arteries. Some patients who undergo device closure of an atrial septal defect complain of headache, which are posited as a migraine. Here we report a case of severe headache due not to migraine but reversible cerebral vasoconstriction syndrome after device closure of a ventricular septal defect.

Long-Term Observational Outcomes after Total Correction of Congenital Heart Disease in Korean Patients with Down Syndrome: A National Cohort Study.

Background: In the present study, the population prevalence and postoperative morbidity and mortality in Down syndrome patients who underwent total correction for congenital heart disease were investigated using data from a large national cohort. Methods: Retrospective administrative data from 2,395,966 participants born between 2008 and 2012 were acquired from the National Investigation of Birth Cohort in Korea. Among Down syndrome patients, 58.3% had congenital heart disease and 32.3% underwent total correction. Propensity score matching (maximum 1:1) and stabilized inverse probability treatment weighting (IPTW) were performed for each group (153 Down syndrome patients and 4482 non-Down syndrome patients). Results: T late mortality rate was significantly higher in the Down syndrome group than in the non-Down syndrome group (8.1% vs. 3.8%). No differences were observed in postoperative heart failure and arrhythmias, but pulmonary hypertension was significantly greater in the Down syndrome group than in the non-Down syndrome group (26.9% vs. 7.0%). The length of hospitalization was longer in the Down syndrome group than in the non-Down syndrome group (14 days vs. 11 days; interquartile range (IQR): 10−25 vs. 6−19; p < 0.0001). After total correction, readmission frequency for any reason was minimally but statistically significantly higher in the Down syndrome group compared to the non-Down syndrome group (5 times vs. 5 times; IQR: 3−8 vs. 4−9; p < 0.0001). However, the number of emergency room visits was minimally but significantly lower in the Down syndrome group compared to the non-Down syndrome group (2 visits vs. 2 visits (IQR): 2−7 vs. 1−4; p = 0.016). Conclusions: Down syndrome patients with congenital heart disease undergoing total correction showed pulmonary hypertension after surgery, longer length of hospitalization, frequent hospitalization after surgery, and a higher rate of late mortality.

Transgenerational effects of polyethylene microplastic fragments containing benzophenone-3 additive in Daphnia magna.

Maternal exposure to microplastics (MPs) plays an important role in the fitness of unexposed progeny. In this study, the transgenerational effects of polyethylene MP fragments (17.35 ± 5.50 µm) containing benzophenone-3 (BP-3; 2.85 ± 0.16% w/w) on chronic toxicity (21 d) in Daphnia magna were investigated across four generations. Only D. magna in the F0 generation was exposed to MP fragments, MP/BP-3 fragments, and BP-3 leachate to identify the transgenerational effect in the F3 generation. The mortality of D. magna induced by MP and MP/BP-3 fragments was recovered in the F3 generation, but somatic growth and reproduction significantly decreased compared to the control. Additionally, reproduction of D. magna exposed to BP-3 leachate significantly decreased in the F3 generation. These findings confirmed the transgenerational effects of MP fragment and BP-3 additive on D. magna. Particularly, the adverse effect on D. magna reproduction seemed to be cumulative across four generations for MP/BP-3 fragments, while it was an acclimation trend for BP-3 leachate. However, there was no significant difference in global DNA methylation in D. magna across four generations, thus requiring a gene-specific DNA methylation study to identify different epigenetic transgenerational inheritance.

Outcomes After Transcatheter Closure of Atrial Septal Defect Without Using a Balloon-Sizing Technique: A Randomized Controlled Comparison with Closures Using a Balloon-Sizing Technique.

BACKGROUND: The transcatheter closure of atrial septal defect could be completed without the balloon-sizing technique, so we evaluated long-term outcomes compared with closure using balloon sizing, which was the conventional method. Even without using the balloon-sizing technique, transcatheter closure of atrial septal defect might be safe and effective. METHODS: We included 124 patients with isolated atrial septal defects who underwent device closure without balloon sizing between 2012 and 2016, and we further included 257 patients as a control group. Patients who received closure with multiple devices or who experienced postoperative residual defects were excluded. Immediate procedural results, as well as long-term outcomes for closure without balloon sizing, were investigated and compared with the control group. RESULTS: The procedural success rate was 96.7%, and there were no mortalities. No embolization or cardiac erosions were observed; however, one patient experienced residual shunt, and another developed progressed mitral regurgitation during the follow-up period (983±682 days). Newly onset persistent atrial fibrillation developed in one patient (1.0%). There were no significant differences in procedures or follow-up between the study and control groups. Despite the shorter procedural time in the study group, fluoro time was not different. Atrial arrhythmias were more frequently observed in the control group, but the difference was not significant. Persistent atrial fibrillation was observed in two patients in the control group (0.8%). CONCLUSIONS: Transcatheter closure of atrial septal defect can be performed safely and effectively without using the balloon-sizing technique. The long-term outcomes were similar to outcomes with balloon sizing.

Development of necrotizing enterocolitis in full-term infants with duct dependent congenital heart disease.

BACKGROUND: Although many studies have described an increased risk of necrotizing enterocolitis in duct dependent congenital heart diseases, very few have investigated its occurrence in full-term infants with duct dependent congenital heart diseases. METHODS: To evaluate the characteristics and risk factors of necrotizing enterocolitis, we performed a retrospective review of 355 full-term infants with duct dependent congenital heart diseases who received prostaglandin E1 therapy from April 2000 to May 2020. RESULTS: Necrotizing enterocolitis was observed in 10 patients (3.0%). Their average gestational age and birth weight were 38.2 weeks and 2783.5 g, respectively. The median age at diagnosis was 8.0 days (2-70 days). One patient was diagnosed with necrotizing enterocolitis stage IIA, five with stage IIB, two with stage IIIA, and two with stage IIIB; two (20%) received surgical treatment. The duct dependent pulmonary circulation group had higher frequencies of necrotizing enterocolitis (4.4%) than the duct dependent systemic circulation (2.0%) and parallel circulation (1.3%) groups. The necrotizing enterocolitis and the other groups had significantly different birth weight (2783.5 g vs 3170.9 g, respectively) and gestational age (38.2 weeks vs 39.1 weeks, respectively). Gestational age under 38 weeks (OR 8.87, p = 0.002), birth weight of < 2500 g (OR 5.1, p = 0.042), need for mechanical ventilation (OR 4.6, p = 0.021), parenteral nutrition (OR 107.7, p < 0.001), and functional single ventricle (OR 5.8, p = 0.009) were significant risk factors. The case-fatality rate was higher in the necrotizing enterocolitis (40.0%) than in the other group (8.3%, p = 0.009). CONCLUSIONS: Three percent of full-term infants with duct dependent congenital heart diseases developed necrotizing enterocolitis. Neonates with low birth weight, gestational age less than 38 weeks, functional single ventricle, or receiving assisted mechanical ventilation or parenteral nutrition are at increased risk.

A Retrospective Population-Based Survival Study of Idiopathic Pulmonary Arterial Hypertension in Korea.

BACKGROUND: Few studies used nationwide data to assess the survival rates (SRs) and death risk for idiopathic pulmonary arterial hypertension (IPAH; ICD-10 I27.0) in Korea. METHODS: IPAH data (N = 9,017; female:male = 6:4) were collected from the National Health Insurance Service in Korea, from 2006 through 2017. The data consisted of primary diagnoses related to IPAH. The Kaplan-Meier method and Cox proportional-hazards analyses were carried out. RESULTS: The mean age was 62.3 (± 19.4) years, 64.2 (± 18.9) years in female and 59.4 (± 19.8) years in male (P < 0.001). The one-, three-, five- and 10-year SRs for IPAH were 89.0%, 79.8%, 72.3% and 57.0%, respectively. The adjusted hazard ratio (HR) of IPAH was 1.81 (95% confidence interval [CI], 1.26-2.59) in 60-69 age group, 3.42 (95% CI, 2.40-4.87) in 70-79, and 7.73 (95% CI, 5.43-11.0) in 80s. Other risk factors were male, low-income status, diabetes, myocardial infarction, atrial fibrillation, ischemic stroke, hemorrhagic stroke, and malignant neoplasm. CONCLUSION: The 10-year SR of IPAH was 57% in Korea. The HR for IPAH was significantly high in patients with older age and other risk factors.

Midterm results of arch augmentation with autologous vascular patch in interrupted aortic arch.

OBJECTIVES: Aortic arch reconstruction of interrupted aortic arch remains challenging, and subsequent problems, including arch and airway stenosis, may occur. Thus, we investigated midterm results of an augmentation technique using autologous vascular patch. METHODS: This retrospective study included 24 patients who underwent arch reconstruction with an autologous vascular patch for interrupted aortic arch with biventricular physiology from 2006 to 2018. The median age and body weight at operation were 10 days (range 4-77 days) and 3 kg (range 2.5-5.1 kg), respectively. The reconstructed arch was supplemented in the lesser curvature with an autologous vascular patch that was harvested from main pulmonary artery (n = 19), left subclavian artery (n = 3) or aberrant right subclavian artery (n = 1). One patient used patches from both the main pulmonary and left subclavian artery. RESULTS: There was 1 early death due to right heart failure. All survivors were discharged 15 days (range 9-58 days) after surgery without residual arch stenosis. Late death occurred in 1 patient with Cri-du-chat syndrome and airway stenosis. Two reoperations and 1 intervention for arch stenosis were performed. The 1-, 5- and 10-year survival was 92%. Freedom from reoperation or intervention for arch stenosis was 86% 1, 5 and 10 years after surgery. No occurrence of arch aneurysm formation, left main bronchial stenosis and significant hypertension was found during a median follow-up period of 5.5 years (range 0.3-13.3 years). CONCLUSIONS: Augmenting the lesser curvature with an autologous vascular patch during arch reconstruction resulted in reasonable midterm outcomes.

How can stretched ductus diameter be predicted from angiographic diameter?

BACKGROUND: An appropriate size of device for patent ductus arteriosus (PDA) could be chosen by a stretched PDA size. We propose prediction of stretched size from intact PDA size. METHODS: A total of 361 patients was enrolled. Intact size was measured on angiography before closure, and stretched size was the narrowest diameter immediately after device implantation. RESULTS: The median patient age was 2.8 years. Intact diameter and stretched diameter were 3.6±1.4 mm and 5.1±1.3 mm. The difference and difference ratio were 1.5±0.8 mm and 51.3±38.1% and had negative linear correlations with age (P<0.001). Patients were divided into four groups: <2 years old (159), 2-15 years old (68), 15-40 years old (72), and ≥40 years old (62). Among groups, difference and difference ratio were significantly different. Stretched diameter was inferred by the following formulas: stretched diameter = 0.660 × intact diameter + 2.791 (<2 years old); = 0.971×intact diameter + 0.058 × age + 1.131 (2-15 years old); = 0.790 × intact diameter + 2.263 (15-40 years old); and = 0.837 × intact diameter + 1.353 × BSA - 0.096 (≥40 years old). CONCLUSIONS: Stretched PDA diameter can be predicted from intact diameter and might be helpful for safe PDA closure especially in small infants.

The Waiting List Mortality of Pediatric Heart Transplantation Candidates in Korea before the Pediatric Ventricular Assist Device Era.

BACKGROUND: Despite advancements in heart transplantation for pediatric patients in Korea, the waiting list mortality has not been reported. Therefore, we investigated the waiting list mortality rate and factors associated with patient mortality. METHODS: We reviewed the medical records of pediatric patients who were registered for heart transplantation at three major hospitals in Korea from January 2000 to January 2020. All patients who died while waiting for heart transplantation were investigated, and we identified the waiting list mortality rate, causes of mortality and median survival periods depending on the variable risk factors. RESULTS: A total of 145 patients received heart transplantations at the three institutions we surveyed, and the waiting list mortality rate was 26%. The most common underlying diseases were cardiomyopathy (66.7%) and congenital heart disease (30.3%). The leading causes that contributed to death were heart failure (36.3%), multi-organ failure (27.2%), and complications associated with extracorporeal membrane oxygenation (ECMO) (25.7%). The median survival period was 63 days. ECMO was applied in 30 patients. The different waiting list mortality percentages according to age, cardiac diagnosis, use of ECMO, and initial Korean Network of Organ Sharing (KONOS) level were determined using univariate analysis, but age was the only significant factor associated with waiting list mortality based on a multivariate analysis. CONCLUSION: The waiting list mortality of pediatric heart transplantation candidates was confirmed to be considerably high, and age, underlying disease, the application of ECMO, and the initial KONOS level were the factors that influenced the survival period.