Normal values of the pulmonary artery acceleration time (PAAT) and the right ventricular ejection time (RVET) in children and adolescents and the impact of the PAAT/RVET-index in the assessment of pulmonary hypertension.

New echocardiographic modalities including pulmonary artery acceleration time (PAAT) and right ventricular ejection time (RVET) are evolving to facilitate an early non-invasive diagnosis for pulmonary hypertension (PH) in adults. In children, PAAT depends on age, body surface area (BSA) and heart rate (HR) and is used to predict PH. Normal values of RVET and their role to predict PH in children are still missing. PAAT/RVET-index correlates negatively with PH. We hypothesized that this index is a good predictor for PH in children and adolescents independent of age, BSA and HR and RVET is significantly reduced in PH. PAAT and RVET of 401 healthy children and 30 PH-patients were measured using pulsed-wave-Doppler. PH was diagnosed in PH-group invasively. PAAT/RVET-index for both groups was calculated. Sensitivity and specificity in prediction of PH of PAAT, PAAT z-score and PAAT/RVET-index were compared. We demonstrated normal values of RVET in children. In the healthy group, PAAT and RVET correlated significant positive to age (p < 0.001), and BSA (p < 0.001) and negative to HR (p < 0.001). PAAT/RVET-index correlated weakly to age, BSA and HR (p < 0.001). Mean pulmonary artery pressure (PAPM) ranged in the PH-group from 27 to 82 mmHg (mean 44 mmHg). In predicting PH, RVET is significantly reduced (p < 0.001). Comparing area under the curve (AUC), the difference between sensitivity and specificity of PAAT/RVET-index < 0.29 and calculated PAAT cut-off-point (87 ms) was significant (p < 0.001). Equally, AUC comparison between PAAT/RVET-index < 0.29 and PAAT z-score of - 1.33 was significant (p = 0.008). PAAT/RVET-index < 0.29 represents a good predictor of PH with a 100% sensitivity and a 95.8% specificity. PAAT/RVET-index is a simple tool and facilitates prediction of PH independent from z-scores.

Validation and Reference Values for Three-Dimensional Echocardiographic Right Ventricular Volumetry in Children: A Multicenter Study.

BACKGROUND: Functional assessment of the right ventricle using real-time three-dimensional echocardiography (RT3DE) has fundamental relevance in young patients with congenital heart disease. Reference values for the pediatric population are scarce. This multicenter study was designed to (1) validate new evaluation software for RT3DE and (2) establish pediatric reference values. METHODS: For validation, right ventricular (RV) end-diastolic volume (EDV) and end-systolic volume (ESV) were determined from real-time three-dimensional echocardiographic data sets of 38 subjects (n = 17 healthy individuals and n = 21 patients with congenital heart disease) using new dedicated evaluation software (RV-Function 2.0) and compared with cardiac magnetic resonance investigations of the same patient cohort. In a prospective multicenter design, 360 real-time three-dimensional echocardiographic data sets of healthy children (172 girls) were analyzed. To create reference centiles, the cohort was subdivided into group I (children <7 years of age, n = 136 [female and male]), group II (girls 7-18 years of age, n = 106), and group III (boys 7-18 years of age, n = 118). RESULTS: Using RT3DE, RV volumes were slightly higher than using cardiac magnetic resonance (EDV, 0.8 ± 5.8% [limits of agreement, -10.8% to 12.5%; r = 0.993]; ESV, 2.0 ± 13.1% [limits of agreement, -24.2% to 28.2%; r = 0.989). Reproducibility was promising (intraobserver variability, 3.9 ± 11.4% for EDV and -1.7 ± 13.4% for ESV [intraclass correlation coefficient range, 0.94-0.98]; interobserver variability, 1.9 ± 11.8% for EDV and -0.3 ± 22.8% for ESV [intraclass correlation coefficient range, 0.85-0.96]). Regarding functional parameters, no significant gender differences were found among children in group I. In contrast, children in groups II and III differed in RV volumes, dimensional parameters, and tricuspid annular plane systolic excursion (P < .005); the children did not differ in deformation parameters. Feasibility was 90%. CONCLUSIONS: RT3DE yields accurate and reproducible RV volumes. The calculated percentile curves may facilitate the clinical use of RT3DE to analyze RV function in children.

Real-Time Three-Dimensional Echocardiography of the Left Ventricle-Pediatric Percentiles and Head-to-Head Comparison of Different Contour-Finding Algorithms: A Multicenter Study.

BACKGROUND: Real-time three-dimensional echocardiography (RT3DE) is a promising method for accurate assessment of left ventricular (LV) volumes and function, however, pediatric reference values are scarce. The aim of the study was to establish pediatric percentiles in a large population and to compare the inherent influence of different evaluation software on the resulting measurements. METHODS: In a multicenter prospective-design study, 497 healthy children (ages 1 day to 219 months) underwent RT3DE imaging of the LV (ie33, Philips, Andover, MA). Volume analysis was performed using QLab 9.0 (Philips) and TomTec 4DLV2.7 (vendor-independent; testing high (TomTec75) and low (TomTec30) contour-finding activity). Reference percentiles were computed using Cole's LMS method. In 22 subjects, cardiovascular magnetic resonance imaging (CMR) was used as the reference. RESULTS: A total of 370/497 (74.4%) of the subjects provided adequate data sets. LV volumes had a significant association with age, body size, and gender; therefore, sex-specific percentiles were indexed to body surface area. Intra- and interobserver variability for both workstations was good (relative bias ± SD for end-diastolic volume [EDV] in %: intraobserver: QLab = -0.8 ± 2.4; TomTec30 = -0.7 ± 7.2; TomTec75 = -1.9 ± 6.7; interobserver: QLab = 2.4 ± 7.5; TomTec30 = 1.2 ± 5.1; TomTec75 = 1.3 ± 4.5). Intervendor agreement between QLab and TomTec30 showed larger bias and wider limits of agreement (bias: QLab vs TomTec30: end-systolic volume [ESV] = 0.8% ± 23.6%; EDV = -2.2% ± 17.0%) with notable individual differences in small children. QLab and TomTec underestimated CMR values, with the highest agreement between CMR and QLab. CONCLUSIONS: RT3DE allows reproducible noninvasive assessment of LV volumes and function. However, intertechnique variability is relevant. Therefore, our software-specific percentiles, based on a large pediatric population, serve as a reference for both commonly used quantification programs.

Centile Curves for Velocity-Time Integral Times Heart Rate as a Function of Ventricular Length: The Use of Minute Distance Is Advantageous to Enhance Clinical Reliability in Children.

BACKGROUND: The generation of velocity-time integrals (VTIs) from Doppler signals is an essential component of standard echocardiographic investigations. The most effective algorithm to compensate for growth in children has, however, not yet been identified. This study was initiated to establish pediatric reference values for VTI and to enhance the interpretability of those values, considering technical and physiological factors. METHODS: The echocardiographic data sets of healthy children and adolescents (N = 349; age range, 0-20 years) were recorded in a prospective approach and subsequently analyzed. In a pilot study, aortic and pulmonary VTIs were set in relation to the physiologic parameters of heart size as possible influencing parameters in a subgroup of children with comparable physical characteristics. The ratio with the smallest SD was taken as the base to generate centile curves using the LMS method. The clinical utility of the model was tested by examining patients (n = 80) with shunt lesions such as patent ductus arteriosus and atrial septal defect. RESULTS: Feasibility was 94.6% for aortic VTI and 92.8% for pulmonary VTI. The pilot study identified ventricular length and heart rate as suitable parameters with the lowest relative SDs and high correlations with VTI. Gender differences were not relevant for children <7 years of age, and with increasing age, SD increased because of higher stroke volume variations. The detection of increased aortic VTI was possible with sensitivity of 73% for patients with patent ductus arteriosus with moderate or large hemodynamically significant ductus arteriosus. Patients with atrial septal defects with enlarged right ventricles could be identified as having increased pulmonary VTI with sensitivity of 84%. CONCLUSIONS: These new reference values for VTI times heart rate as a function of ventricular length may be of specific clinical value to improve the assessment of cardiac function, therapeutic decision making, and follow-up in pediatric patients with heart disease.

High proportion of genetic cases in patients with advanced cardiomyopathy including a novel homozygous Plakophilin 2-gene mutation.

Cardiomyopathies might lead to end-stage heart disease with the requirement of drastic treatments like bridging up to transplant or heart transplantation. A not precisely known proportion of these diseases are genetically determined. We genotyped 43 index-patients (30 DCM, 10 ARVC, 3 RCM) with advanced or end stage cardiomyopathy using a gene panel which covered 46 known cardiomyopathy disease genes. Fifty-three variants with possible impact on disease in 33 patients were identified. Of these 27 (51%) were classified as likely pathogenic or pathogenic in the MYH7, MYL2, MYL3, NEXN, TNNC1, TNNI3, DES, LMNA, PKP2, PLN, RBM20, TTN, and CRYAB genes. Fifty-six percent (n = 24) of index-patients carried a likely pathogenic or pathogenic mutation. Of these 75% (n = 18) were familial and 25% (n = 6) sporadic cases. However, severe cardiomyopathy seemed to be not characterized by a specific mutation profile. Remarkably, we identified a novel homozygous PKP2-missense variant in a large consanguineous family with sudden death in early childhood and several members with heart transplantation in adolescent age.

Differentiation of Impaired From Preserved Hemodynamics in Patients With Fontan Circulation Using Real-time Phase-velocity Cardiovascular Magnetic Resonance.

PURPOSE: Progressive impairment of hemodynamics in patients with Fontan circulation is common, multifactorial, and associated with decreased quality of life and increased morbidity. We sought to assess hemodynamic differences between patients with preserved (preserved Fontans) and those with impaired circulation (impaired Fontans) after pulmonary vasodilation using oxygen and under forced breathing conditions. MATERIALS AND METHODS: Real-time phase-contrast cardiovascular magnetic resonance was performed using non-ECG triggered echo-planar imaging (temporal resolution=24 to 28 ms) in the ascending aorta (AAo) and superior vena cava (SVC)/inferior vena cava (IVC) on room air, after 100% oxygen inhalation (4 L/min; 10 min) and on forced breathing in 29 Fontan patients (17.2±7.3 y) and in 32 controls on room air (13.4±3.7 y). The simultaneously recorded patients' respiratory cycle was divided into 4 segments (expiration, end-expiration, inspiration, and end-inspiration) to generate respiratory-dependent stroke volumes (SVs). The imaging data were matched with physiological data and analyzed with home-made software. RESULTS: The mean SVi (AAo) was 46.1±11.1 mL/m in preserved Fontans versus 30.4±6.2 mL/m in impaired Fontans (P=0.002) and 51.1±6.9 mL/m in controls (P=0.107). The cutoff value for differentiation of Fontan groups was SVi (AAo, end-expiratory) of 32.1 mL/m. After hyperoxygenation, the mean SVi (AAo) increased to 48.7±12.7 mL/m in preserved Fontans (P=0.045) but remained unchanged in impaired Fontans (31.1±5.8 mL/m, P=0.665). Simultaneously, heart rates decreased from 75.2±15.9 to 70.8±16.4 bpm (preserved; P=0.000) but remained unchanged in impaired circulation (baseline: 84.1±9.8 bpm, P=0.612). Compared with physiological respiration, forced breathing increased the maximum respiratory-related cardiac index difference (ΔCImax) in preserved Fontans (SVC: 2.5-fold, P=0.000; and IVC: 1.8-fold, P=0.000) and to a lower extent in impaired Fontans (both veins, 1.5-fold; P(SVC)=0.011, P(IVC)=0.013). There was no impact on mean blood flow. CONCLUSIONS: Oxygen affected the pulmonary vascular system by vasodilation and increased SVi in preserved Fontans but had no effect on impaired Fontans. Forced breathing increased ΔCImax but did not change the mean blood flow by sole activation of the ventilatory pump. End-expiratory aortic SVi represents a valuable measure for classifying the severity of Fontan hemodynamics impairment.

The "Dog Bone Technique" A Novel Easy and Safe Catheter Maneuver for Aortic Arch and Coarctation Stenting.

BACKGROUND: Various techniques are described to facilitate stable stent implantation in aortic arch stenosis or coarctation. We describe an alternative technique, which due to its unique appearance during stent implantation, we have named "Dog Bone Technique" (DBT). TECHNIQUE: The stent/balloon assembly is placed across the stenosis, the long sheath is retrieved to uncover the distal 20-50% of the stent. The balloon is inflated with the pressure inflator just to expand slightly the stent. Thereafter the sheath is pulled back and the proximal end is uncovered and partially inflated; therewith the assembly takes the typical "dog bone" shape before complete inflation and final positioning. Repositioning of the stent and control angiography is possible at each time of this procedure. RESULTS: Between 1/2010 and 12/2014 we implanted 91 stents in 87 patients (mean age 20.2 years). About 71 patients had native or re-coarctation and 16 patients had transverse aortic arch stenosis. In 38 patients (44%) a pharmacological exercise test with Orciprenaline was performed during implantation resulting in high-cardiac output. In none of the patients reduction of cardiac output by adenosine or a rapid pacing of the right ventricle was required for stable stent implantation. All stents were implanted in the targeted position using this single balloon technique. There were no acute or short-term complications detected. CONCLUSION: DBT is a safe and feasible technique for aortic stent implantation even at high-cardiac output. Other additional techniques for stent placement are not necessary to obtain a stable final position in the target region.

Eisenmenger syndrome and long-term survival in patients with Down syndrome and congenital heart disease.

OBJECTIVE: To characterise patients with trisomy 21 (Down syndrome, DS) based on the data of the German National Register for Congenital Heart Defects, to identify changes in the availability of surgical therapy over time and to analyse the impact of these changes on developing Eisenmenger syndrome (ES) as well as survival. METHODS: Out of 1549 patients with DS with congenital heart disease in the National Register for Congenital Heart Defects, 894 patients (55% female, mean age 17.5 years) had a post-tricuspid shunt lesion (atrioventricular septal defect 69.5%, ventricular septal defect 27.7%, patent arterial duct 2.6%) and were included in the current study. RESULTS: The likelihood of being treated interventionally or surgically before the age of 1 year increased significantly over time. In parallel, the likelihood of developing ES decreased over time (53% birth cohort during 1950s/1960s vs 0.5% birth cohort during 2000-2009, p<0.0001). Overall survival after 1, 10, 20 and 40 years was 96.8%, 94.1%, 92.6% and 75.5%, respectively. Patients with ES had a significantly worse survival compared with those without ES (HR 18.1; 95% CI 7.2 to 45.4; p<0.0001). CONCLUSIONS: The availability of surgical correction was associated with a decrease in the likelihood of developing ES. Patients with DS still have reduced survival prospects compared with the general population, but this effect is largely driven by patients developing ES who still have a very poor prognosis.

Cause of death in adults with congenital heart disease - An analysis of the German National Register for Congenital Heart Defects.

BACKGROUND: Due to the great advances in the care of patients with congenital heart disease (CHD), mortality has decreased significantly over the last decades. Nonetheless, mortality for adults with congenital heart disease (ACHD) is still higher than for the general population. An analysis regarding causes of death in a nationwide contemporary cohort of ACHD is lacking. METHODS: A well-characterized cohort of the German National Register for Congenital Heart Defects was screened for patients over the age of 18 years who died between January 2001 and January 2015. Data relating to the cardiac diagnosis, symptoms, operations, interventions, comorbidities, and causes of death were analyzed. RESULTS: During a median follow-up of 3.67 years (IQR 1.32-9.41), 239 (9.2%) out of 2596 patients died during the study period (110 female (46%), mean age at death 39.8 ± 17.8 years). The majority of these deaths was CHD-related (171 patients (71.5%)). Leading causes of death were heart failure (n=66, 27.6%), and sudden cardiac death (n=55, 23.0%). Deceased patients had a more complex CHD and more extracardiac comorbidities compared with living patients. CONCLUSIONS: Causes of death of ACHD patients in a large contemporary cohort from a national register are in the majority still CHD-related, with heart failure being the leading cause of death. Additionally, extracardiac comorbidities gain increasing importance.

Three parties, one direction: Research priorities in adults with congenital heart disease. What do professionals, patients and relatives want to know?

BACKGROUND: Patients, their relatives, as well as medical specialists from the fields of paediatric cardiology, cardiology and cardiac surgery were surveyed to investigate the current research needs in the field of congenital heart disease (CHD) focussing specifically on the needs of those affected. MATERIAL AND METHODS: An online survey including four groups of patients with CHD (Fontan circulation, transposition of the great arteries [TGA] after atrial switch [AS] and after arterial switch operation [ASO], tetralogy of Fallot [TOF]) was performed. Each questionnaire comprised twelve topics. Persons affected (patients and relatives) were surveyed by means of CHD group specific questionnaires. Participants were recruited through the German National Register for Congenital Heart Defects. RESULTS: N=596 affected persons (Fontan circulation: n=189; TGA after AS: n=64; TGA after ASO: n=90; TOF: n=253) and 75 physicians (57.3% paediatric cardiologists, 28.0% cardiologists, 10.7% cardiac surgeons, 4.0% other) participated. In general, those affected assume a greater need for research than physicians. Regarding the CHD related topics to be the focus of future research, those affected largely agreed with the participating physicians, although with a different ranking of research topics. CONCLUSIONS: Based on the results of our study the challenges immanent in routine care for the CHD patient groups investigated can be identified. Accordingly, these topics should be prioritized in the research of the coming years.

Representativeness of the German National Register for Congenital Heart Defects: a clinically oriented analysis.

BACKGROUND: Approximately 6000 children are born with CHD in Germany each year. It is increasingly rare that these children die from their chronic illness. In the present study, data recorded in the National Register for Congenital Heart Defects with respect to the prevalence of specific lesions and sex distribution are compared with that recorded in a published German prevalence study (Prevalence Study) and with the meta-analysis by van der Linde et al. METHODS: A descriptive data analysis was performed using a minimal data set. The demographic data included sex and birth year; the medical data comprised the cardiovascular diagnosis according to the short list of the International Paediatric and Congenital Cardiac Code. RESULTS: As the data analysis shows, the National Register is a clinical register including primarily clinical cases/cases relevant to healthcare. The prevalence values and sex ratios recorded in the register are closer to the values given in the literature than those determined by the Prevalence Study. Severe CHD was slightly over-represented in the National Register compared with the van der Linde et al meta-analysis. The deviations with respect to prevalence values are within an acceptable range. CONCLUSION: With its 48,000 patients, the National Register plays a unique and important role for research in the field of CHD. Samples from the National Register can be used as a gold standard for future studies, as the patient population registered in it can be considered representative of CHD in Germany and Europe.

Long-Term Mechanical Circulatory Support in Pediatric Patients.

This retrospective study reviews our results regarding the long-term support in pediatric patients using two ventricular assist systems between January 2008 and April 2014. We implanted the Berlin Heart EXCOR in 29 patients (median age 3.4 years [interquartile range (IQR) 0.2-16.5], median weight 13 kg [IQR 4.2-67.2]). Twenty-two patients (75.8%) received a left ventricular assist device. Three patients (10.3%) had single-ventricle physiology. One patient (3.4%) had mechanical mitral valve prosthesis. The HeartWare System was implanted in nine patients. The median age was 15.6 years (IQR 12.2-17.9), and the median weight was 54.9 kg (IQR 27.7-66). In the Berlin Heart group, the median support time was 65 days (IQR 4-619), with 3647 days of cardiac support. Nineteen patients (65.5%) were transplanted, six patients (20.7%) recovered, one patient (3.4%) is on support, and three patients (10.3%) died on support. Survival rate was 89.7%. Fourteen blood pumps had been exchanged. Four patients (13.8%) had local signs of infection, and three patients (10.3%) had neurological complications. In the HeartWare group, the median support time was 180 days (IQR 1-1124), with 2839 days of cardiac support. Four patients (44.4%) had local signs of infection, and three (33.3%) had neurological complications. Eight patients (88.9%) have been transplanted, and one patient (11.1%) died on support. Survival rate was 88.9%. Excellent survival is possible after long-term mechanical circulatory support in patients with two- and single-ventricle physiology with a low rate of adverse events.

"Intraoperative hybrid stenting of recurrent coarctation and arch hypoplasia with large stents in patients with univentricular hearts".

BACKGROUND: Obstruction of the reconstructed aortic arch, tubular hypoplasia and recurrent coarctation (RC) is an important risk factor in univentricular physiology. For the past two years we have adopted the concept of intraoperative hybrid stenting of RC and arch hypoplasia with large stents in patients with univentricular hearts as standard care procedure. METHOD/RESULT: Retrospective analysis of the anatomy and procedural outcome of 14 patients was scheduled for intraoperative stenting of the aortic arch (12 during surgery for BCPS, 2 during Fontan completion). The median age was 5.3 months, weight 5.5 kg, height 62 cm. Five patients had tubular hypoplasia and 9 patients had distal stenosis of the aortic arch. Nine patients had a previous balloon dilatation. The mean diameter of the distal arch was 11.0mm, at the coarctation 5.1mm, at the level of the diaphragm 8.2mm (CoA-index 0.62). Intraoperative stenting was performed in 13/14 patients. Stents were implanted with a mean balloon diameter of 10.8mm (SD 3.4mm). The achieved final mean diameter was 9.8mm (mean, SD 2.8mm) with an oversized Coa-index of 1.2. There was no re-coarctation at a mean follow-up of 7.3 months (range 3 to 24), the maximum flow velocity of 2m/s across the stented lesion assessed by ECHO. CONCLUSION: This hybrid approach is an easy and safe concept to manage recurrent aortic arch hypoplasia and stenosis. The use of large stents allows redilatation to adult size diameters later on.

Optimal septum alignment of the Figulla Flex occluder to the atrial septum in patients with secundum atrial septal defects.

AIMS: To investigate the implantation safety, anatomic performance and septal alignment of the Occlutech Figulla Flex occluder (FFO) device, an atrial septal defect (ASD) closure device with specific left-sided deployment characteristics and right-sided septal alignment properties. METHODS AND RESULTS: Between January 2011 and December 2013 we prospectively collected the change of orientation of the device to the septum during the release process and the feasibility of implantation of the FFO in 122 patients. The mean age was 10.7 years (±10.2), weight 32.9 kg (±20.3), and height 129.4 cm (±30). Devices used were 9 (n=13), 10.5 (n=16), 12 (n=16), 15 (n=39), 18 (n=17), 21 (n=8), 24 (n=5), 27 (n=7) and 30 mm (n=3) in size. No additional implantation techniques were required. Before release, the mean angles of the left and right-sided discs were 29.2° (±9.9°) and 43.4° (±9.2°) to the body axis, and 18.7° (±8.7°) and 27.0° (±10°) immediately thereafter. Thus, there was only a slight change in orientation of the left-sided (10.6°±7.5°) and right-sided (16.3°±7.9°) discs. CONCLUSIONS: The design of this occluder system results in an ideal septum alignment which increases its feasibility as well as patient safety during implantation.

Bovine Jugular Veins versus Homografts in the Pulmonary Position: An Analysis across Two Centers and 711 Patients-Conventional Comparisons and Time Status Graphs as a New Approach.

BACKGROUND: Various diseases and diversity in implantation ages, together with evolving diagnostic and therapeutic options, hinder comparative evaluations of long-term outcomes for valved conduits used for reconstruction of the right ventricular outflow tract (RVOT). We combined two common evaluation methods to optimally use information obtained by pooling the raw data from two high volume centers, each with very regular follow-up procedures, with the aim of analyzing durability differences between conventional homografts and bovine jugular veins. PATIENTS AND METHODS: In the period 1985 to 2012, a total of 444 bovine jugular veins and 267 homografts were implanted, and 6,738 postoperative examinations took place. Evaluations included age-stratified Kaplan-Meier analyses, Cox regression models, and time status graphs, the third showing age-group stratified, time-related frequencies of intact, insufficient, stenotic, both insufficient and stenotic, and postinterventional conduits below the freedom from explantation curve. They take into account interventions, explantations, and the nonterminal character of echocardiographic findings. RESULTS: The durability of intact bovine jugular veins in children and young adults is not inferior to that of homografts. Averaged over the first 12 years after implantation, the age groups < 25 years in fact showed advantages for bovine jugular vein recipients. The average fraction of patients younger than 25 years whose conduits were not explanted, postinterventional, stenotic, insufficient, or stenotic and insufficient was at least 10% higher in recipients of bovine jugular veins than in homograft recipients. CONCLUSION: According to the time status graphs, the use of bovine jugular veins for RVOT in patients younger than 25 years appears to lead to superior results when compared with cryopreserved homografts.

Substantial radiation reduction in pediatric and adult congenital heart disease interventions with a novel X-ray imaging technology.

BACKGROUND: Pediatric catheterization exposes patients to varying radiation doses. Concerns over the effects of X-ray radiation dose on the patient population have increased in recent years. This study aims at quantifying the patient radiation dose reduction after the introduction of an X-ray imaging technology using advanced real time image noise reduction algorithms and optimized acquisition chain for fluoroscopy and exposure in a pediatric and adult population with congenital heart disease. METHODS: Patient and radiation dose data was retrospectively collected (July 2012-February 2013) for 338 consecutive patients treated with a system using state of the art image processing and reference acquisition chain (referred as "reference system"). The same data was collected (March-October 2013) for 329 consecutive patients treated with the new imaging technology (Philips AlluraClarity, referred as "new system"). Patients were divided into three weight groups: A) below 10 kg, B) 10-40 kg, and C) over 40 kg. Radiation dose was quantified using dose area product (DAP), while procedure complexity using fluoroscopy time, procedure duration and volume of contrast medium. RESULTS: The new system provides significant patient dose reduction compared to the reference system. Median DAP values were reduced in group A) from 140.6 cGy·cm2 to 60.7 cGy·cm2, in group B) from 700.0 cGy·cm2 to 202.2 cGy·cm2 and in group C) from 4490.4 cGy·cm2 to 1979.8 cGy·cm2 with reduction of 57%, 71% and 56% respectively (p < 0.0001 for all groups). CONCLUSIONS: Despite no other changes in procedural approach, the novel X-ray imaging technology provided substantial radiation dose reduction of 56% or higher.

Implantation of the new Nit-Occlud PDA-R device in children below 10 kilogram.

BACKGROUND: Interventional closure of patent ductus arteriosus (PDA) has become a common and safe procedure in most pediatric cath labs. Interventional treatment of PDAs still remains a challenge in those children with low body weight and a large PDA. The Nit-Occlud PDA-R® device was developed and especially designed for large PDAs. We report our most recent experience in children with a body weight lower than 10 kg. MATERIALS AND METHODS: The PDA-R® device was used in seven children (age 1-10, median 6 months) with a body weight from 4.1 to 9.7 kg (median 5.9 kg): ductal length was 12 mm (median), with a large ampulla (median 9 mm) which exceeded the diameter of the aorta (median 6 mm) and large diameter (median minimal diameter 4 mm). In six cases, the Nit-Occlud PDA-R was selected with an aortic disc of 12 mm and in one case an occluder with an aortic disc of 14 mm. RESULTS: Occlusion of the PDA was documented by angiography and/or echocardiography in all cases. At a mean follow-up of 21.4 months, no flow obstruction to the left or right pulmonary artery or new onset coarctation of the aorta was noted. CONCLUSIONS: The Nit-Occlud PDA-R® device is suitable in children with a body weight below 10 kg when a relative large PDA is present.

Impact of respiration on stroke volumes in paediatric controls and in patients after Fontan procedure assessed by MR real-time phase-velocity mapping.

AIMS: Blood flow rate quantification using two-dimensional phase-contrast MRI (PC-MRI) results in averaging of flow information due to long acquisition times precluding the examination of short-term effects. The aim of this study was to determine respiration-related flow rate variations by non-electrocardiographic triggered real-time phase-contrast MRI (PC-MRI). METHODS AND RESULTS: Real-time PC-MRI was applied to study respiration-driven blood flow fluctuations in the ascending aorta (AAo), superior vena cava (SVC), and inferior vena cava (IVC) under normal and forced breathing in 33 healthy children and 10 Fontan patients. Respiration-dependent flow rates were virtually generated by dividing the respiration curve into four segments: expiration, end-expiration, inspiration, and end-inspiration. Whereas in volunteers aortic flow rate was elevated during end-expiration (5.6 ± 3.0%) and decreased during end-inspiration (-5.8 ± 3.5%) in relation to mean blood flow (P < 0.05), highest flow was detected during inspiration in SVC (10.5 ± 14.1%) and IVC (22.5 ± 12.1%) and lowest flow during expiration (-11.6 ± 13.5%, -13.2 ± 14.1%, P < 0.05). Differences were increased under forced breathing in AAo (10.4 ± 5.5%, -7.4 ± 6.5%, P < 0.05) and SVC (40.0 ± 30.3%, -30.0 ± 19.2%, P < 0.05), whereas were unchanged in IVC (16.5 ± 23.6%, -13.7 ± 21.6%, P = n.s.). Regarding patients, respiratory-dependent flow rate variability was increased and had to be related to the patient's individual quality of Fontan circulation. CONCLUSION: Real-time PC-MRI allows a physiological assessment of respiratory-related flow rate fluctuations in healthy subjects as well as in Fontan patients. Its capability for detection of short-term effects in clinical routine was demonstrated.