Impact of Pulmonary Arterial Elastance on Right Ventricular Mechanics and Exercise Capacity in Repaired Tetralogy of Fallot

Background and Objectives@#Pathophysiological changes of right ventricle (RV) after repair of tetralogy of Fallot (TOF) are coupled with a highly compliant low-pressure pulmonary artery (PA) system. This study aimed to determine whether pulmonary vascular function was associated with RV parameters and exercise capacity, and its impact on RV remodeling after pulmonary valve replacement. @*Methods@#In a total of 48 patients over 18 years of age with repaired TOF, pulmonary arterial elastance (Ea), RV volume data, and RV-PA coupling ratio were calculated and analyzed in relation to exercise capacity. @*Results@#Patients with a low Ea showed a more severe pulmonary regurgitation volume index, greater RV end-diastolic volume index, and greater effective RV stroke volume (p=0.039, p=0.013, and p=0.011, respectively). Patients with a high Ea had lower exercise capacity than those with a low Ea (peak oxygen consumption [peak VO2 ] rate: 25.8±7.7 vs. 34.3±5.5 mL/kg/min, respectively, p=0.003), while peak VO2 was inversely correlated with Ea and mean PA pressure (p=0.004 and p=0.004, respectively). In the univariate analysis, a higher preoperative RV end-diastolic volume index and RV end-systolic volume index, left ventricular end-systolic volume index, and higher RV-PA coupling ratio were risk factors for suboptimal outcomes. Preoperative RV volume and RV-PA coupling ratio reflecting the adaptive PA system response are important factors in optimal postoperative results. @*Conclusions@#We found that PA vascular dysfunction, presenting as elevated Ea in TOF, may contribute to exercise intolerance. However, Ea was inversely correlated with pulmonary regurgitation (PR) severity, which may prevent PR, RV dilatation, and left ventricular dilatation in the absence of significant pulmonary stenosis.

Long-term Outcome of Fontan-Associated Protein-Losing Enteropathy: Treatment Modality and Predictive Factor of Mortality

Background and Objectives@#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. @*Methods@#We reviewed the medical records of 38 patients with Fontan-associated PLE from 1992 to 2018 in 2 institutions in Korea. @*Results@#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 11.6years. 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). @*Conclusions@#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.

A Comparison of Physical Activity and Exercise Capacity in Adults with Congenital Heart Disease and Healthy Controls / 대한스포츠의학회지

Purpose@#Advancements in surgical and nonsurgical care for congenital heart disease (CHD) have enabled an increase in survival into adulthood of these children with CHD, thereby contributing to the growth of the aging population, it is important to evaluate these functional outcome measures in adults with CHD. Therefore, this study aimed to compare the subjective and objective assessments of physical activity (PA) and exercise capacity (EC) in adults with CHD and age-matched, healthy controls. @*Methods@#Forty-six adults with CHD (male, 26; age, 20.6±1.3 years) and forty-six healthy controls (male, 24; age, 21.2±1.6 years) underwent an assessment of subjective and objective PA levels using the Global Physical Activity Questionnaire and the accelerometer device (GENEActiv) worn on the wrist for seven consecutive days, respectively.EC was directly measured by peak oxygen uptake (peak VO2 ) during a graded exercise test. @*Results@#Subjectively and objectively measured of moderate to vigorous PA in adults with CHD were lower than those with healthy controls (p=0.008, p=0.004), while the majority of adults with CHD have achieved the recommended levels of PA (150 min/wk). In addition, peak VO2 was lower in adults with CHD than in healthy controls (30.8±8 mL/kg/min vs. 46.7±10 mL/kg/min, p＜ 0.001). @*Conclusion@#Although the majority of adults with CHD meet the recommended levels of PA, their overall PA levels and EC are still lower than those of age-matched, healthy adults without CHD.

The outcome of percutaneous stent implantation in congenital heart disease: experience of a single institute / 소아과

PURPOSE: The efficacy of percutaneous stent implantation for congenital heart disease (CHD) in Korea, where stent availability is limited, has not been determined. This study evaluated the acute and midterm results of stent implantation in different CHD subgroups. METHODS: Stents were implanted in 75 patients with 81 lesions: (1) pulmonary artery stenosis (PAS) group, 56 lesions in 51 patients; (2) coarctation of the aorta (CoA) group, 5 lesions in 5 patients; (3) Fontan group, 13 lesions in 12 patients; (4) ductal stent group, 3 lesions in 3 patients; and (5) other CHD group, 4 lesions in 4 patients. Mean follow-up duration was 2.1 years (0.1–4 years). Medical records were reviewed retrospectively. RESULTS: The minimum lumen diameter (MLD) in PAS and CoA increased from 5.0±1.9 mm and 8.4±1.6 mm to 10.1±3.6 mm and 12.3±2.5 mm, respectively (P<0.01). In the PAS group, pressure gradient decreased from 25.7±15.6 mmHg to 10.4±10.1 mmHg, and right ventricular to aortic pressure ratio from 0.56±0.21 to 0.46±0.19. In the CoA group, the pressure gradient decreased from 50±33 mmHg to 17±8 mmHg. In the ductal stent group, the MLD of the ductus increased from 2.3 mm to 4.3 mm and arterial oxygen saturation from 40%–70% to 90%. No deaths were associated with stent implantation. Stent migration occurred in 3 patients, but repositioning was successful in all. Stent redilation was performed successfully in 26 cases after 29±12 months. CONCLUSION: Percutaneous stent implantation was safe and effective, with acceptable short and mid-term outcomes in Korean CHD patients.

Idiopathic midaortic syndrome with malignant hypertension in 3-year-old boy / 소아과

Midaortic syndrome (MAS) is a rare vascular disease that commonly causes renovascular hypertension. The lumen of the abdominal aorta narrows and the ostia of the branches show stenosis. MAS is associated with diminished pulses in the lower extremities compared with the upper extremities, severe hypertension with higher blood pressure in the upper rather than lower extremities, and an abdominal bruit. The clinical symptoms are variable, and recognition in children with hypertension can aid early diagnosis and optimal treatment. Hypertension with MAS is malignant and often refractory to several antihypertensive drugs. Recently, radiologic modalities have been developed and have led to numerous interventional procedures. We describe the case of a 3-year-old boy presenting with left ventricular hypertrophy whose severely elevated blood pressure led to the diagnosis of idiopathic MAS. This case highlights the importance of measuring blood pressure and conducting a detailed physical examination to diagnose MAS. This is the first reported case of idiopathic MAS diagnosed in childhood in Korea.

The strong association of left-side heart anomalies with Kabuki syndrome / 소아과

PURPOSE: Kabuki syndrome is a multiple congenital malformation syndrome, with characteristic facial features, mental retardation, and skeletal and congenital heart anomalies. However, the cardiac anomalies are not well described in the Korean population. We analyzed the cardiac anomalies and clinical features of Kabuki syndrome in a single tertiary center. METHODS: A retrospective analysis was conducted for a total of 13 patients with Kabuki syndrome. RESULTS: The median age at diagnosis of was 5.9 years (range, 9 days to 11 years and 8 months). All patients showed the characteristic facial dysmorphisms and congenital anomalies in multiple organs, and the diagnosis was delayed by 5.9 years (range, 9 days to 11 years and 5 months) after the first visit. Noncardiac anomalies were found in 84% of patients, and congenital heart diseases were found in 9 patients (69%). All 9 patients exhibited left-side heart anomalies, including hypoplastic left heart syndrome in 3, coarctation of the aorta in 4, aortic valve stenosis in 1, and mitral valve stenosis in 1. None had right-side heart disease or isolated septal defects. Genetic testing in 10 patients revealed 9 novel MLL2 mutations. All 11 patients who were available for follow-up exhibited developmental delays during the median 4 years (range, 9 days to 11 years 11 months) of follow-up. The leading cause of death was hypoplastic left heart syndrome. CONCLUSION: Pediatric cardiologist should recognize Kabuki syndrome and the high prevalence of left heart anomalies with Kabuki syndrome. Genetic testing can be helpful for early diagnosis and counseling.

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

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.

Ruptured Tricuspid Valve Papillary Muscle in a Neonate with Intractable Persistent Fetal Circulation

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.