QT interval in children with orthostatic dysregulation: Changes in standing load.

BACKGROUND: The corrected QT interval (QTc) is affected by changes in autonomic sympathovagal modulation. The aim of this study was to determine whether children with orthostatic dysregulation (OD) have a longer QTc while standing than children without OD. METHODS: We retrospectively assessed patients who underwent the Schellong test and electrocardiography between November 2016 and November 2019. Patients who met the criteria of OD subtypes according to the Japanese clinical guidelines for juvenile OD (version 1) were classified as OD positive (the OD-positive group), and patients who did not meet the criteria were classified as OD negative (the OD-negative group). RESULTS: There were 73 patients in the OD-positive group and 52 patients in the OD-negative group. Baseline heart rate, QT interval, and QTc were comparable between the OD-positive and OD-negative groups. Heart rate after standing was significantly higher in the OD-positive group than in the OD-negative group (median: 33 bpm vs. 21 bpm, p < 0.001). Further, shortening of QT interval after standing was greater in the OD-positive group than in the OD-negative group (median: 19 ms vs. 8 ms, p = 0.015). The QTc significantly increased from baseline to standing in both groups. Changes in the QT interval corrected by Bazett's formula were greater in the OD-positive group than in the OD-negative group (median: 73 ms vs. 42 ms, p < 0.001). CONCLUSIONS: The QTc increased significantly from baseline to standing in the OD-positive group. Thus, a high QTc while standing could be considered an auxiliary marker for OD diagnosis.

Legionella pneumophila and Other Legionella Species Isolated from Legionellosis Patients in Japan between 2008 and 2016.

The Legionella Reference Center in Japan collected 427 Legionella clinical isolates between 2008 and 2016, including 7 representative isolates from corresponding outbreaks. The collection included 419 Legionella pneumophila isolates, of which 372 belonged to serogroup 1 (SG1) (87%) and the others belonged to SG2 to SG15 except for SG7 and SG11, and 8 isolates of other Legionella species (Legionella bozemanae, Legionella dumoffii, Legionella feeleii, Legionella longbeachae, Legionella londiniensis, and Legionella rubrilucens). L. pneumophila isolates were genotyped by sequence-based typing (SBT) and represented 187 sequence types (STs), of which 126 occurred in a single isolate (index of discrimination of 0.984). These STs were analyzed using minimum spanning tree analysis, resulting in the formation of 18 groups. The pattern of overall ST distribution among L. pneumophila isolates was diverse. In particular, some STs were frequently isolated and were suggested to be related to the infection sources. The major STs were ST23 (35 isolates), ST120 (20 isolates), and ST138 (16 isolates). ST23 was the most prevalent and most causative ST for outbreaks in Japan and Europe. ST138 has been observed only in Japan, where it has caused small-scale outbreaks; 81% of those strains (13 isolates) were suspected or confirmed to infect humans through bath water sources. On the other hand, 11 ST23 strains (31%) and 5 ST120 strains (25%) were suspected or confirmed to infect humans through bath water. These findings suggest that some ST strains frequently cause legionellosis in Japan and are found under different environmental conditions.IMPORTANCELegionella pneumophila serogroup 1 (SG1) is the most frequent cause of legionellosis. Our previous genetic analysis indicated that SG1 environmental isolates represented 8 major clonal complexes, consisting of 3 B groups, 2 C groups, and 3 S groups, which included major environmental isolates derived from bath water, cooling towers, and soil and puddles, respectively. Here, we surveyed clinical isolates collected from patients with legionellosis in Japan between 2008 and 2016. Most strains belonging to the B group were isolated from patients for whom bath water was the suspected or confirmed source of infection. Among the isolates derived from patients whose suspected infection source was soil or dust, most belonged to the S1 group and none belonged to the B or C groups. Additionally, the U group was discovered as a new group, which mainly included clinical isolates with unknown infection sources.

Assessment of the helical ventricular myocardial band using standard echocardiography.

BACKGROUND: The purpose of this study was to assess the feasibility of morphological and functional evaluation of the helical ventricular myocardial band using standard echocardiographic images. METHODS: Echocardiographic data were obtained from 132 normal children. We attempted to identify the echogenic bright line serving as the boundary between the ascending and descending segments in the ventricular septum, and between the left and ascending segments in the left ventricular inferior wall in the helical myocardial band model proposed by Torrent-Guasp. Myocardial deformations on both sides of the bright line were compared using speckle tracking echocardiography. RESULTS: The bright line separating the ascending from descending segment was visible in the mid-ventricular septum in the four-chamber view in all subjects. This echogenic boundary was observed obliquely in the parasternal short-axis view in 116 subjects (87.9%). There was no significant difference in peak longitudinal or circumferential strain between the ascending and descending segments. However, the time from the QRS onset to peak circumferential strain was significantly lower in the descending than ascending segment (394.5 ± 37.0 vs. 432.7 ± 33.1 ms, P < 0.0001), whereas there was no significant difference in the time to peak longitudinal strain (394.4 ± 26.4 vs. 393.2 ± 24.1 ms). The bright line between the left and ascending segment was detected in the short-axis view from the subcostal region in 86 subjects (65.2%). The time to peak circumferential strain was significantly lower in the left than ascending segment (380.1 ± 32.0 vs. 435.7 ± 37.9 ms, P < 0.0001). CONCLUSION: There is a helical ventricular myocardial band that can be observed in standard echocardiographic images.

Fibromyxoid excrescence of the aortic valve that manifested after catheterisation and required resection.

A 2-year-old boy developed fibromyxoid excrescence of the aortic valve 2 years after balloon dilatation for simple coarctation. Transthoracic echocardiography showed a mobile mass on the non-coronary cusp of the aortic valve. Definitive diagnosis was achieved after operative resection. This pathology was attributed to injury during catheter manipulation. Catheterised patients should be followed up carefully to avoid missing morphological changes.

Assessment of two-component ventricular septum: functional differences in systolic deformation and rotation assessed by speckle tracking imaging.

BACKGROUND: The purpose of this study was to elucidate functional differences in the right and left components of the ventricular septum (Rt and Lt, respectively). METHODS: Strain, strain rate, rotation, and rotation rate profile curves of Rt and Lt were obtained using speckle tracking echocardiography in 38 normal children and adolescents. RESULTS: The echogenic bright line serving as the boundary separating Rt from Lt was consistently visible in the middle of the ventricular septum. There was no significant difference in peak strain or peak strain rate during systole between Rt and Lt. However, the time interval from the onset of QRS-wave to peak strain and peak strain rate were significantly lower in Lt than in Rt in terms of radial and circumferential deformation (P < 0.005, all), whereas there was no significant difference in longitudinal deformation in the time to peak strain or peak strain rate between Rt and Lt. Lt showed counterclockwise rotation, whereas Rt showed clockwise rotation (10.4 ± 2.9° vs. -10.2 ± 2.6°, P < 0.0001). Time to peak rotation was significantly lower in Lt than in Rt (201.7 ± 32.7 msec vs. 370.4 ± 31.2 msec, P < 0.0001). CONCLUSION: Morphologically and functionally the ventricular septum is a two-component structure. Evaluation of deformation and rotation of the 2 components would help in evaluating septal performance.

Left atrial volume change throughout the cardiac cycle in children with congenital heart disease associated with increased pulmonary blood flow: evaluation using a novel left atrium-tracking method.

There is a paucity of data regarding the significance of left atrial (LA) volume and its changes throughout the cardiac cycle in pediatric patients with heart disease. The recently developed LA volume-tracking (LAVT) method can automatically construct the LA volume curve. The study group consisted of 48 pediatric patients with ventricular septal defect (n = 34) or patent ductus arteriosus (n = 14) and age-matched healthy controls. Maximum and minimum LA volumes (LAVmax and LAVmin, respectively) were measured. The total LA emptying volume (LAVtotal) was defined as LAVmax--LAVmin. Volume parameters were standardized by dividing by body surface area (BSA). The total LA emptying fraction (%LAVtotal) was defined as the ratio of LAVtotal to LAVmax. In the patient group, there was a positive correlation between the ratio of pulmonary to systemic blood flow (Qp/Qs) and LAVmax/BSA, LAVmin/BSA, and LAVtotal/BSA (r = 0.42, 0.44, and 0.34, respectively). LAVmin/BSA was positively correlated with the ratio of early mitral inflow velocity to early mitral annular diastolic tissue Doppler velocity (E/E') (r = 0.32). The %LAVtotal had a negative correlation with left-ventricular (LV) end-diastolic pressure (r = -0.32). There were significant correlations between serum B-type natriuretic peptide level and LAVmax/BSA, LAVmin/BSA, and %LAVtotal (r = 0.38, 0.49, and -0.35, respectively). The LAVT method is useful in the evaluation of LV diastolic function in pediatric patients with chronic LV volume overload.

Ratio of early diastolic tricuspid inflow to tricuspid lateral annulus velocity reflects pulmonary regurgitation severity but not right ventricular diastolic function in children with repaired Tetralogy of Fallot.

The current study assessed relationships between the ratio of early diastolic tricuspid inflow to tricuspid lateral annular velocity (tricuspid E/e') and right ventricular (RV) function in children after tetralogy of Fallot (TOF) repair. The RV function of 25 asymptomatic children with surgically repaired TOF (age 3.3 ± 2.0 years) was assessed by echocardiography and cardiac catheterization. Right ventricular end-diastolic pressure and volume (RVEDP and RVEDV), systolic pressure, and ejection fraction, as well as mean pulmonary arterial pressure, mean right atrial pressure (RAP), and the severity of both pulmonary regurgitation (PR) and tricuspid regurgitation (TR) were assessed in terms of the contribution to tricuspid E/e'. Univariate analysis discovered a relationship between tricuspid E/e' and RVEDV (R(2) = 0172), pressure half-time of PR (PR-PHT) (R(2) = 0.173), and TR grade (R(2) = 0.145) (p < 0.01 for each). After multivariate adjustment, PR-PHT was significantly associated with tricuspid E/e' (ß = 0.210; p < 0.001). Tricuspid E/e' was not significantly associated with RVEDP or RAP. In conclusion, tricuspid E/e' does not indicate RV diastolic function but reflects the severity of PR in asymptomatic children after TOF repair.

Subclavian and pulmonary artery steal phenomenon in a patient with isolated left subclavian artery and right aortic arch.

We describe a patient with an isolated left subclavian artery associated with right aortic arch, patent ductus arteriosus, and ventricular septal defect. As the isolated left subclavian artery is supplied by the left vertebral artery in which blood flows in the retrograde direction, this anomaly is usually responsible for a congenital subclavian steal phenomenon. Atrophy of the left cerebral hemisphere and inverted left vertebral arterial flow were clearly depicted by echoencephalography in this patient, whose subclavian artery was connected to the main pulmonary artery by a patent ductus arteriosus.

A Case with Iron Deficiency Anemia Developed Aplastic Crisis.

A toddler with an unbalanced diet and gastrointestinal bleeding by juvenile polyp developed an aplastic crisis due to the human parvovirus B19 (HPVB19). Although he exhibited microcytic anemia without iron deficiency in the acute phase of HPVB19 infection, he presented with iron deficiency anemia (IDA) in the chronic phase. IDA results in erythroblast hyperplasia and shortened red blood cell lifespan as like congenital hemolytic diseases, which may lead to an aplastic crisis during HPVB19 infection. It should be noted that iron deficiency is often masked, and microcytic anemia may be a clue for IDA.

The Limited Effect of a History of COVID-19 on Antibody Titers and Adverse Reactions Following BNT162b2 Vaccination: A Single-Center Prospective Study.

Background and Objectives: The need for, and ideal frequency of, the vaccination against coronavirus disease 2019 (COVID-19) of previously infected individuals have not yet been sufficiently evaluated. The aim of this study was to examine the anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody status and adverse reactions after vaccination among medical staff with or without a history of COVID-19. Materials and Methods: A single-center prospective study was performed at Fukuoka University Chikushi Hospital. We investigated the presence of the anti-SARS-CoV-2 antibody titer among medical staff before and after mRNA vaccination with the BNT162b2. The levels of immunoglobulin G antibody were quantitatively measured at six points-before vaccination, after the first vaccination, at three points after the second vaccination, and finally, after the third vaccination-and the levels were then compared based on the COVID-19 infection history. Results: The previously infected (before the first vaccination) subjects (n = 17) showed a marked increase in antibody titers two weeks after the first vaccination and four weeks after the second vaccination. Although they were able to maintain a certain level of antibody titers until 30 weeks after the second vaccination, the titers fell in the same way as observed in the non-infected subjects. The subjects who did not receive the third vaccination due to adverse reactions to previous vaccines (n = 1) or who were positive for COVID-19 prior to the third vaccination (n = 2) were excluded from the subsequent analyses. Among non-infected subjects (n = 36), smokers had lower peak antibody titers than the others. The previously infected subjects had a significantly higher incidence of adverse reactions after the first vaccination but had a similar incidence of adverse reactions after the second and third vaccinations compared to the non-infected subjects. Conclusions: A history of COVID-19 may influence only the initial increase in anti-SARS-CoV-2 antibody titers and the occurrence of adverse reactions after the first vaccination.

Serum concentration of heart-type fatty acid-binding protein in children and adolescents with congenital heart disease.

BACKGROUND: Serum heart-type fatty acid-binding protein (H-FABP) is widely applied as a marker of cardiac myocyte injury. Recently, it has been reported that levels of H-FABP are elevated in adult patients with chronic heart failure and thus provide useful prognostic information. The aim of the present study was to examine the relationships between serum H-FABP levels and pathophysiological characteristics in children and adolescents with congenital heart disease (CHD). METHODS AND RESULTS: Serum H-FABP levels were preoperatively and postoperatively measured in 238 consecutive patients with CHD aged 1-31 years. The relationships between H-FABP levels and severity of heart failure, circulatory status and laboratory data were cross-sectionally analyzed. Multivariate regression analysis indicated that serum H-FABP levels are independently affected by age, New York Heart Association functional class, creatine kinase MB, creatinine and arterial oxygen saturation (standard regression coefficients, -0.378, 0.237, 0.422, 0.615, and -0.210, respectively). Neither left ventricular ejection fraction nor B-type natriuretic peptide correlated with H-FABP levels. CONCLUSIONS: H-FABP could serve as a new monitoring tool to provide information that will guide the optimal therapy and management of CHD patients.

Cell membrane stretch activates intermediate-conductance Ca2+-activated K+ channels in arterial smooth muscle cells.

The aim of this study is to determine the signal transduction of membrane stretch on intermediate-conductance Ca(2+)-activated K(+) (IKca) channels in rat aorta smooth muscle cells using the patch-clamp technique. To stretch the cell membrane, both suction to the rear end of patch pipette and hypotonic shock were used. In cell-attached and inside-out patch configurations, the open probability of IKca channels increased when 20- to 45-mmHg suction was applied. Hyposmotic swelling efficiently increased IKca channel current. When the Ca(2+)-free solution was superfused, the activation of IKca current by the hyposmotic swelling was reduced. Furthermore, gadolinium (Gd(3+)) attenuated the activation of IKca channels induced by hyposmotic swelling, whereas nicardipine did not. In the experiments with Ca(2+)-free bath solution, pretreatment with GF109203X, a protein kinase C (PKC) inhibitor, completely abolished the stretch-induced activation of IKca currents. The stretch-induced activation of IKca channels was strongly inhibited by cytochalasin D, indicating a role for the F-actin in modulation of IKca channels by changes in cell stretching. These data suggest that cell membrane stretch activates IKca channels. In addition, the activation is associated with extracellular Ca(2+) influx through stretch-activated nonselective cation channels, and is also modulated by the F-actin cytoskeleton and the activation of PKC.

Pulmonary emphysematous changes in patients with congenital heart disease associated with increased pulmonary blood flow: evaluation using multidetector-row computed tomography.

BACKGROUND: The present study aimed to evaluate the prevalence and the location of segmental emphysematous change in congenital heart disease (CHD) patients with increased pulmonary blood flow using multidetector-row computed tomography (MDCT). METHODS: A total of 129 consecutive patients (mean age, 5.8±5.4 years; range, 1 month to 24 years) underwent MDCT angiography of the thorax. The frequency of emphysematous change was evaluated in patients with ventricular septal defect (VSD, n=61), atrial septal defect (ASD, n=27), patent ductus arteriosus (PDA, n=36) and complete atriventriclar septal defect (CAVSD, n=5). In 59 patients who underwent cardiac catheterisation, the relationships between the emphysematous change and both pulmonary to systemic blood flow ratio (Qp/Qs) and mean pulmonary arterial pressure (mPAP) were evaluated. RESULTS: The emphysematous change was detected in 57 patients (44.2%) out of 129 patients. The frequency of segmental emphysematous change in left side was higher than in right side (14.8% vs. 6.5%). Both Qp/Qs and mPAP affected the presence of emphysema. CONCLUSION: MDCT can provide accurate detection of segmental emphysema in patients with CHD. Emphysematous change is not uncommon pathological lesion in children and adolescents with CHD.

Assessment of modified Blalock-Taussig shunt in children with congenital heart disease using multidetector-row computed tomography.

The purpose of this study was to assess the feasibility of multidetector-row computed tomography (MDCT) for the evaluation of modified Blalock-Taussig (B-T) shunt in children with congenital heart disease associated with reduced pulmonary blood flow. A total of 25 consecutive patients (mean age, 2.6 ± 3.6 years; range, 2 months-16 years) underwent MDCT angiography of the thorax with a 16-detector row scanner prior to cardiac catheterization. A total of 39 shunts (right, 22; left, 17) were included in the study. Conventional angiographic findings were used as the gold standard for the detection of B-T shunts. Shunt diameter was measured quantitatively and independently at four sites (the subclavian artery site, the pulmonary artery site, the widest site, and the stenotic site) on MDCT and on conventional invasive angiography. All B-T shunts were depicted on multiplanar reconstruction (MPR), maximum intensity projection (MIP), curved planar reconstruction (CPR), and three-dimensional volume-rendered (VR) images, enabling evaluation in all patients except for one with occluded shunt. There were excellent correlations between MDCT- and conventional angiography-based measurements of shunt diameter at the subclavian artery site, pulmonary artery site, and the widest site (R² = 0.46, 0.74 and 0.64, respectively; p < 0.0001 for each), although systematic overestimation was observed for MDCT (mean percentage of overestimation, 23.1 ± 32.4%). Stenotic site diameter and degree of stenosis showed a mild correlation (R² = 010 and 0.25, respectively; p < 0.01 for each). This study demonstrates that MDCT is a promising tool for the detection of lesions in B-T shunts.

Tracheal compression due to an elongated aortic arch in patients with congenital heart disease: evaluation using multidetector-row CT.

BACKGROUND: The airway can become obstructed as a result of compression by an elongated aortic arch. OBJECTIVE: In this study we evaluated tracheal compression using multidetector-row CT in patients with congenital heart disease and an elongated aortic arch. MATERIALS AND METHODS: The trachea was measured at the level of the aortic arch in 205 children and young adults and then the severity of tracheal compression was determined by measuring the tracheal diameter ratio (short axis diameter/long axis diameter). Patients were divided as follows: group I (normal aortic arch; n=166), group II (transversely running aortic arch; n=22), and group III (elongated aortic arch; n=17). From the viewpoint of the relationship of the great arteries, group II had D-malposition, and group III had L-malposition. RESULTS: Age, height, weight and body surface area were significantly correlated with the short and long axis diameter in group I. There was a negative correlation between tracheal diameter ratio and the physical size parameters. The tracheal diameter ratio in group III was 0.50+/-0.13, which was significantly lower than in groups I and II (P<0.01 and 0.05, respectively). CONCLUSION: Even apparently asymptomatic patients with an elongated aortic arch can have tracheal compression. An elongated aortic arch may be a useful predictor of tracheal compression.

Stenting of ductus arteriosus in a neonate with truncus arteriosus and interrupted aortic arch associated with a right aortic arch.

This report describes a case in which successful stenting of ductus arteriosus (DA) was performed for a 27-day-old boy with truncus arteriosus (TA) and interrupted aortic arch (IAA). The patent DA was associated with a right aortic arch. During the balloon catheter crossing of the ductus, the DA and descending aorta shifted toward the left side, making appropriate stent placement difficult. Additionally, the DA was longer than in previously reported cases with left aortic arch, thus requiring a longer stent. This experience suggests that DA stenting in neonates with TA and IAA averts surgical repair during the early neonatal period.

Distribution of lag-1 Alleles, ORF7, and ORF8 Genes of Lipopolysaccharide and Sequence-Based Types Among Legionella pneumophila Serogroup 1 Isolates in Japan and China.

Approximately 85% of cases of Legionnaires' disease are caused by Legionella pneumophila serogroup 1. In this study, we analyzed the distribution of lag-1 alleles, ORF 7 and ORF 8 genes of lipopolysaccharide (LPS) and sequence-based types of 616 L. pneumophila serogroup 1 strains isolated in Japan (206 clinical, 225 environmental) and China (13 clinical and 172 environmental). The lag-1 gene was harbored by significantly more of the clinical isolates compared with the environmental isolates (90.3 vs. 19.1% and 61.6 vs. 3.0%, respectively; both P < 0.001). ORF 7 genes were detected in 51.0% of Japanese clinical and 36.0% of Japanese environmental (P = 0.001) isolates, as well as 15.3% of Chinese clinical and 9.9% of Chinese environmental isolates (P = 0.544). ORF 8 genes were detected in 12.1% of Japanese clinical and 5.8% of Japanese environmental (P = 0.017) isolates, as well as 7.7% of Chinese clinical and 3.4% of Chinese environmental isolates (P = 0.388). The Japanese and Chinese isolates were assigned to 203 and 36 different sequence-types (ST), respectively. ST1 was predominant. Most isolates with the same ST also had the same lag-1, ORF 7, and ORF 8 gene subgroups. In conclusion, the lag-1 was present in most of the clinical isolates, but was absent from most of the environmental isolates from both China and Japan, regardless of the water source and SBT type. PCR-based serotyping and subgrouping methods can be used to define a hierarchy of virulence genotypes that require stringent surveillance to prevent human disease.

Polytetrafluoroethylene graft calcification in patients with surgically repaired congenital heart disease: evaluation using multidetector-row computed tomography.

BACKGROUND: Noninvasive determination of calcified prosthetic polytetrafluoroethylene (PTFE) is important in improving risk stratification. The purpose of this study is to assess the feasibility of multidetector-row computed tomography (MDCT) for the evaluation of PTFE calcification in patients with surgically repaired congenital heart disease and to evaluate the development and characteristics of calcification for specific surgical procedures. METHODS: Seventy-six implanted PTFE grafts in 47 patients were evaluated by MDCT (Aquillion 16, Toshiba Corporation, Tokyo, Japan). Explanted PTFE grafts were evaluated histologically in 4 patients who underwent reoperation after MDCT scans. RESULTS: Calcification of prosthetic PTFE was detected in 5 of 29 cases (17%) for ventricular septal defect (VSD) patches, 26 of 32 (81%) for right ventricular outflow tract (RVOT) prosthesis, 2 of 8 (25%) for atrial septal patches of the Fontan procedure, and 7 of 7 (100%) for extracardiac conduits of total cavopulmonary connection. The CT attenuation of PTFE revealed significantly different values for VSD patches (114 +/- 61 Hounsfield units [HU]), RVOT prosthesis (243 +/- 132 HU), atrial septal patches (163 +/- 161 HU), and extracardiac conduits (230 +/- 29 HU) (P < .0001). The CT density value of VSD patches was significantly lower than those of RVOT grafts and extracardiac conduits (P < .05). The MDCT findings were consistent with histologic analysis in the evaluation of calcification. CONCLUSIONS: This study demonstrates that MDCT enables the evaluation of prosthetic PTFE graft calcification; PTFE grafts in 4 different implantation sites demonstrated distinctive features and the prevalence of calcification.