Cardiac manifestations of human ACTA2 variants recapitulated in a zebrafish model.

The ACTA2 gene encodes actin α2, a major smooth muscle protein in vascular smooth muscle cells. Missense variants in the ACTA2 gene can cause inherited thoracic aortic diseases with characteristic symptoms, such as dysfunction of smooth muscle cells in the lungs, brain vessels, intestines, pupils, bladder, or heart. We identified a heterozygous missense variant of Gly148Arg (G148R) in a patient with a thoracic aortic aneurysm, dissection, and left ventricular non-compaction. We used zebrafish as an in vivo model to investigate whether or not the variants might cause functional or histopathological abnormalities in the heart. Following the fertilization of one-cell stage embryos, we injected in vitro synthesized ACTA2 mRNA of wild-type, novel variant G148R, or the previously known pathogenic variant Arg179His (R179H). The embryos were maintained and raised for 72 h post-fertilization for a heart analysis. Shortening fractions of heart were significantly reduced in both pathogenic variants. A histopathological evaluation showed that the myocardial wall of ACTA2 pathogenic variants was thinner than that of the wild type, and the total cell number within the myocardium was markedly decreased in all zebrafish with pathogenic variants mRNAs. Proliferating cell numbers were also significantly decreased in the endothelial and myocardial regions of zebrafish with ACTA2 variants compared to the wild type. These results demonstrate the effects of ACTA2 G148R and R179H on the development of left ventricle non-compaction and cardiac morphological abnormalities. Our study highlights the previously unknown significance of the ACTA2 gene in several aspects of cardiovascular development.

Ongoing vascular inflammation evaluated by 18F-fluorodeoxyglucose positron emission tomography in patients long after Kawasaki disease.

BACKGROUND: This study aimed to determine whether ongoing vascular inflammation presents in patients who had coronary artery aneurysms (CAAs) caused by Kawasaki disease (KD). METHODS: Subjects were 26 patients with a history of KD; 15 had giant CAA (gCAA) ≥ 8.0 mm and 11 had smaller CAA (smCAA) < 8 mm in the acute phase. They underwent X-ray computed tomography and 18F-fluorodeoxyglucose positron emission tomography. We determined the maximum coronary target-to-background ratio (CaTBR) and the mean thoracic aorta TBR (TaTBR) in each patient. They were compared between groups, and their correlation with various variables was determined. RESULTS: CaTBR and TaTBR were significantly higher in gCAA than in smCAA (P < .005 for both values) and were significantly higher even in patients without any metabolic risk factor (P < .05 for both values). The CAA size in acute phase significantly positively correlated with CaTBR (R2 = 0.32) as well as TaTBR (R2 = 0.28). Also, TaTBR significantly positively correlated with CaTBR (R2 = 0.32) as well as cumulative number of metabolic risk factors (trend, P = .03). CONCLUSIONS: Ongoing vascular inflammation may present long after KD, especially in patients with severe inflammation expressed as gCAA in the acute phase.

Three Cases of KCNT1 Mutations: Malignant Migrating Partial Seizures in Infancy with Massive Systemic to Pulmonary Collateral Arteries.

KCNT1 mutations are gain-of-function mutations in potassium channels resulting in severe infantile epilepsy. Herein we describe 3 infants with malignant migrating partial seizures with KCNT1 mutations accompanied by massive systemic to pulmonary collateral arteries with life-threatening hemoptysis and heart failure.

Intra-cardiac echocardiography-guided stent implantation into stenosed superior vena cava in a patient with a history of contrast anaphylaxis.

A 37-year-old patient, who suffered from a repeated superior vena cava (SVC) syndrome, was scheduled for stent implantation into SVC, but suffered from contrast anaphylaxis. To monitor the procedure, we used intra-cardiac echocardiography and successfully implanted a stent. Placing an intra-cardiac echocardiographic catheter in the main pulmonary artery and facing towards the right, we could readily visualize stenosis in the SVC and inflation of the stent. Also looking up from right atrium, we noted proximal obstruction of the stent and confirmed the relief of obstruction after additional balloon dilation. This report leads to new application of intra-cardiac echocardiography for intervention of structural and vascular diseases other than inter-atrial septum.

Trans-pulmonary echocardiography as a guide for device closure of patent ductus arteriosus.

OBJECTIVES: The aim of this study was to develop trans-pulmonary echocardiography (TPE) to guide device closure of patent ductus arteriosus (DC-PDA). BACKGROUND: Aortography requires a large amount of contrast yet may give us an inadequate image to evaluate anatomy or residual shunt in patients with large PDA or dilated vessels and is precluded in patients with renal dysfunction. Practically, there is no imaging modality to monitor the entire procedure except for trans-esophageal echocardiography that requires general anesthesia. METHODS: Subjects were seven patients with ages ranged from 6- to 77-years old and body weight > 15 kg. The size of the PDA ranged from 1.8 to 6.3 mm with pulmonary to systemic flow ratios from 1.2 to 2.2. During DC-PDA using Ampaltzer Duct Occluder or coil, an intra-cardiac echocardiographic (ICE) catheter was advanced into pulmonary arteries and standard views were developed to guide DC-PDA. RESULTS: We have developed two standard views; the main pulmonary artery view (MPA view) and the left pulmonary artery view (LPA view). The MPA view provided aortic short axis view equivalent to that seen by trans-thoracic echocardiography in children. The LPA view, obtained by the echo probe in the LPA and turned it up upside down, provided long axis view of the PDA allowing more precise anatomical evaluation. TPE allowed us to monitor the entire procedure and determine residual shunts. CONCLUSIONS: TPE in the MPA and LPA view can be an effective guide for DC-PDA. This report leads to new application of this imaging device.

Transpulmonary echocardiography to guide stent implantation into coarctation of the aorta.

Although stent implantation into aortic coarctation has been performed solely under fluoroscopy, we successfully applied intracardiac echocardiography (ICE) to guide this procedure in a 13-year-old patient. Placing an intracardiac echocardiographic catheter in the left pulmonary artery facing upward, we readily visualized the precise anatomy of coarctation, measured the pressure gradient, and monitored the stent inflation process. This report suggests a new application of ICE for intervention with structural and vascular diseases other than interatrial septum.

Long-term prognosis of patients with Kawasaki disease complicated by giant coronary aneurysms: a single-institution experience.

BACKGROUND: Some patients with Kawasaki disease develop giant coronary aneurysms and coronary stenosis, leading to ischemic heart disease. The aim of this study was to determine the long-term prognosis of patients with Kawasaki disease with giant aneurysms. METHODS AND RESULTS: From our institutional database, 76 patients (57 men and 19 women) who developed giant aneurysms after January 1, 1972, were identified. Information on patient demographics, catheter and surgical interventions, and most recent status was collected from medical charts and patients' contacts. From these data, we calculated the survival rate and cumulative coronary intervention rate. The average age at onset was 2.9±2.9 years, and the median observational period was 19 years. During this period, 7 patients died and 1 patient underwent a heart transplantation, resulting in 95%, 88%, and 88% survival rates at 10, 20, and 30 years after the onset of KD, respectively. On the other hand, catheter and surgical coronary interventions (median, 1 intervention; range, 1 to 7 interventions) were performed to alleviate coronary ischemia in 46 patients (61%) at 1 month to 21 years (mode at 1 month) after onset, resulting in 28%, 43%, and 59% cumulative coronary intervention rates at 5, 15, and 25 years after onset, respectively. CONCLUSIONS: The long-term survival of patients with Kawasaki disease complicated by giant coronary aneurysms is moderately good with multiple catheter and surgical interventions. Further research should focus on the prevention of coronary vascular remodeling and on the indications for and effectiveness of percutaneous and surgical coronary interventions.

Increased plasma type B natriuretic peptide in the acute phase of Kawasaki disease.

BACKGROUND: The aim of this study was to identify possible factors associated with type-B natriuretic peptide (BNP) production in the acute phase of Kawasaki disease (KD). METHODS: Subjects were 54 patients with KD (KD group [KDG]) and 18 age-matched controls (control group [CG]). We evaluated left ventricular function using multi-modal echocardiography and determined blood chemistry including BNP, white blood cell count, C-reactive protein (CRP), and interleukin (IL)-6 in the KDG. We compared echocardiographic parameters between the KDG and the CG and determined the correlation between log (BNP) and echocardiographic parameters, white blood cell count, CRP, and IL-6 in the KDG. RESULTS: The KDG showed high BNP (169.6 ± 529.6 pg/ml) despite preserved left ventricular function indicated by no significant difference in left ventricular ejection fraction (72.2 ± 9.2 vs 71.2 ± 7.8 %), z-score of left ventricular diastolic dimension (0.8 ± 1.3 vs 0.9 ± 0.8 SD), and Tei index (0.29 ± 0.09 vs 0.30 ± 0.06) between the KDG and the CG. However, left ventricular ejection fraction (r =-0.44, P= .001) and left ventricular end-diastolic dimension (r = 0.30, P < .05) significantly correlated with log (BNP). On the other hand, the KDG showed high CRP (89.7 ± 55.6 mg/l) and high IL-6 (242.2 ± 243.5 pg/ml), and CRP (r = 0.60, P < 0.0001) and IL-6 (r = 0.78, P < 0.0001) significantly correlated with log (BNP). Multiple stepwise regression analysis identified IL-6 (r = 0.77, P < 0.0001) most significantly correlated with log (BNP). CONCLUSIONS: In acute KD, BNP significantly increases, despite well-preserved global left ventricular function, and inflammation might be associated with this increased BNP.

Microembolic signals measured by transcranial Doppler during transcatheter closure of atrial septal defect using the Amplatzer septal occluder.

PURPOSE: To determine the frequency and factors associated with increase in microembolic signals during transcatheter closure of atrial septal defect using the Amplatzer septal occluder. METHODS: During the procedure in 16 patients, we measured microembolic signals using transcranial Doppler. Procedure time was divided into five periods: right cardiac catheterisation; left cardiac catheterisation; left cardiac angiocardiography; sizing and long sheath placement; device placement and release. We compared numbers of microembolic signals among the five periods and identified factors associated with them. RESULTS: Mean size of septal occluder was 16 millimetres in diameter. Total number of microembolic signals was a median of 31.5, ranging from 3 to 113. Microembolic signals in three periods, left cardiac catheterisation; sizing, and long sheath placement; and device placement and release, were not significantly different from one another, but were significantly higher than those in the remaining two periods, right cardiac catheterisation and left cardiac angiocardiography (median was 9 in left cardiac catheterisation; 6 in sizing and long sheath placement; 6.5 in device placement and release, versus 0 in right cardiac catheterisation and 1 in left cardiac angiocardiography, p less than 0.05, respectively). Importantly, the time for device manipulation positively correlated with total number of microembolic signals (r equals 0.77, p less than 0.001), although fluoroscopic time, age, or size of septal occluder did not. CONCLUSIONS: Transcatheter closure of atrial septal defect using the Amplatzer septal occluder produces microemboli, especially during device placement. To minimise the risk of systemic embolism, we must decrease the time for device manipulation.

Growth differentiation factor 15 as a useful biomarker of heart failure in young patients with unrepaired congenital heart disease of left to right shunt.

BACKGROUND: Growth differentiation factor 15 (GDF 15) is a member of the transforming growth factor-beta superfamily and is considered to be a useful biomarker for severity of heart failure (HF) in repaired congenital heart disease (CHD). The aim of this study was to determine the clinical implication of GDF 15 in children with unrepaired CHD. METHODS: Subjects included 69 patients (≤14 years old) who had unrepaired CHD with left to right shunt and underwent cardiac catheterization. Demographic and hemodynamic data, including oxygen demand-supply relationship, were collected from medical records. Severity of HF was evaluated using modified Ross score. Serum GDF 15 levels were determined using enzyme-linked immunosorbent assay and correlated with patients' demographics, hemodynamic data, and blood chemistry data. RESULTS: Subjects had median age of 71 (range 1-173) months and simple acyanotic CHDs with mean pulmonary to systemic flow ratio of 2.0 (1.0-5.6), median N-terminal pro type Brain natriuretic peptide (NT-pro-BNP) of 162.8 (17.1-8789) pg/mL, and median GDF 15 of 242.1 (13.6-1116.7) pg/mL. GDF 15 significantly positively correlated with the modified Ross score, mean pulmonary artery pressure, oxygen extraction rate (OER), and Ln NT-pro-BNP, but negatively correlated with age, oxygen delivery and its components, and estimated glomerular filtration rate (eGFR). Multiple linear regression analysis revealed significant correlation of GDF 15 levels with the modified Ross score, OER, and eGFR. CONCLUSIONS: GDF 15 mainly reflects oxygen demand-supply relationship and can be used as a diagnostic marker of HF in unrepaired CHD with left to right shunt for a wide range of age and diagnoses.

Catheter ablation in children and patients with congenital heart disease: Review of 1021 procedures at a high-volume single center in Japan.

BACKGROUND: Although pediatric catheter ablation therapy has often been described, few reports on outcomes in a large series of patients at a single center are available. OBJECTIVE: The purpose of this study was to evaluate arrhythmia substrates, outcomes, and complications of catheter ablation in children and patients with congenital heart disease (CHD) performed at a single center. METHODS: We retrospectively analyzed all pediatric patients <18 years and patients of all ages with CHD who underwent ablation therapy between June 2006 and May 2018. RESULTS: A total of 1021 ablation procedures were performed in 877 patients (median age 12.5 years; range 2 months to 67 years). This cohort included 152 CHD patients, 90 small patients (<15 kg), and 14 infants (<1 year). The most frequent indication was Wolff-Parkinson-White pattern (WPW) (n = 287 [32.7%]). Of the 55 patients with asymptomatic WPW, 40 patients (72.7%) had retrograde accessory pathway conduction. Overall success and recurrence rates were 93.5% and 17.3%, respectively. Small patients and CHD patients had lower success rates. No deaths occurred. Serious complications occurred in 5 patients. CONCLUSION: Catheter ablation is safe and effective for treatment of arrhythmia in pediatric and CHD patients. However, ablation was less successful in small patients and CHD patients. The risk of complications was similar to those previously reported for catheter ablation in pediatric, CHD, and adult patients.

Successful combined intravenous and subcutaneous immunoglobulin treatment for intractable protein-losing enteropathy in a patient long after Fontan-type operation.

A 20-year-old patient, who had double outlet right ventricle, mitral atresia, pulmonary atresia, and bilateral superior vena cava and underwent successful lateral tunnel total cavo-pulmonary connection at 6 years old, presented with frequent watery diarrhea, general malaise, and tetany. He was known to have intractable protein-losing enteropathy (PLE) from 7 years of age that was resistant to various treatments. To keep hemodynamics stable, he required intravenous albumin infusion every day. Fontan fenestration partially improved his condition and allowed to stop albumin infusion, however still he showed muddy stool and cachexia with low serum albumin <20 g/L and immunoglobulin <3 g/L. Because of serious risk of infection, we placed him on regular subcutaneous immunoglobulin supplementation with rescue intravenous immunoglobulin that improved his PLE within a month and allowed him to be discharged. This case illustrates that immunoglobulin supplementation can be one of the choices of treatment for intractable PLE. .

Stanford type B aortic dissection associated with pregnancy in patients with Marfan syndrome-A case report and review of the literature.

A 36-year-old female patient known to have Marfan syndrome (MFS) presented with Stanford type B aortic dissection (type B-AD) 3 days after delivery although she had taken oral ß-blocker and underwent prophylactic cesarean section at 34 weeks when she showed 42 mm of the ascending aorta. She was successfully treated medically without further progression of the dissection. A review of the literature revealed an additional 19 patients with MFS who suffered from type B-AD associated with pregnancy. Of 20 patients, 1 (5%) died but the remaining 19 patients were successfully treated either medically (n = 9) or surgically (n = 10). Of 13 patients whose aortic diameter was known, 5 showed <40 mm of the ascending aorta. Pregnancy in MFS can be complicated by type B-AD with a peak around term delivery irrespective of the size of ascending aorta and even with ß-blocker.

Portal-systemic encephalopathy after Fontan-type operation in patient with polysplenia syndrome.

An 18-year-old patient, who had polysplenia and single ventricle, presented with altered mental status 9 years after a Fontan-type operation and pacemaker implantation. He underwent replacement of common atrioventricular valve and aortic valve plasty 1 year previously and has been placed on multiple medications including beta-blocker for his poor ventricular function. Blood chemistry revealed hyperammonemia of 2420 microg/l as a cause of this altered mental status disturbance. Superior mesenteric arteriography revealed large portal-systemic shunts in venous phase as a cause of hyperammonemia. To control blood ammonia level, we placed him on low protein diet, oral polymixin B, and lactulose instead of closing shunt with device. This case illustrates that portal-systemic shunt may result in hyperammonemia leading to altered mental status long after a Fontan-type operation.

Impact of intravenous immunoglobulin infusion on longitudinal left ventricular performance in patients with acute Kawasaki disease of usual course.

PURPOSE: To determine the acute change in cardiac performance after intravenous immunoglobulin infusion (IVIG) in patients with acute Kawasaki disease (KD). MATERIALS AND METHODS: Subjects were 33 patients with KD who were treated with IVIG 2 g/kg and recovered without coronary artery lesion and 27 controls. Subjects underwent combined two-dimensional, Doppler, and tissue Doppler echocardiographic (TDI) studies. In KD, these echocardiographic studies were performed before IVIG, 48 h after IVIG, and in convalescence. Echocardiographic variables were compared between KD and controls as well as among 3 time points in KD. RESULTS: Before IVIG, KD showed significantly higher peak aortic velocity and shorter aortic ejection time as results of tachycardia and significantly lower E' (p<0.04) but significantly higher E/E' (p<0.02). After IVIG, patients with KD became afebrile and showed significantly lower TDI indices such as S', E', and, A' and isovolumic acceleration (IVA) (163+/-56 vs. 208+/-70 cm/s(2), p<0.01) with higher TDI-derived Tei index (0.50+/-0.10 vs. 0.44+/-0.06, p<0.02) than controls. These differences tended to disappear in convalescence. In analysis of repeated measurements, except for hemodynamic changes associated with tachycardia, S' (7.9+/-1.3 vs. 7.0+/-1.1 vs. 7.4+/-0.9 cm/s, p<0.001), IVA (227+/-72 vs. 163+/-56 vs. 180+/-63, p<0.05), and A' (7.7+/-3.0 vs. 5.6+/-1.3 vs. 6.7+/-2.3 cm/s, p<0.001) were significantly different among these time points. CONCLUSIONS: In patients with acute KD with usual course, IVIG induced transient sub-clinical longitudinal left ventricular dysfunction.