Organisation of paediatric echocardiography laboratories and governance of echocardiography services and training in Europe: current status, disparities, and potential solutions. A survey from the Association for European Paediatric and Congenital Cardiology (AEPC) imaging working group.

BACKGROUND: There is limited data on the organisation of paediatric echocardiography laboratories in Europe. METHODS: A structured and approved questionnaire was circulated across all 95 Association for European Paediatric and Congenital Cardiology affiliated centres. The aims were to evaluate: (1) facilities in paediatric echocardiography laboratories across Europe, (2) accredited laboratories, (3) medical/paramedical staff employed, (4) time for echocardiographic studies and reporting, and (5) training, teaching, quality improvement, and research programs. RESULTS: Respondents from forty-three centres (45%) in 22 countries completed the survey. Thirty-six centres (84%) have a dedicated paediatric echocardiography laboratory, only five (12%) of which reported they were European Association of Cardiovascular Imaging accredited. The median number of echocardiography rooms was three (range 1-12), and echocardiography machines was four (range 1-12). Only half of all the centres have dedicated imaging physiologists and/or nursing staff, while the majority (79%) have specialist imaging cardiologist(s). The median (range) duration of time for a new examination was 45 (20-60) minutes, and for repeat examination was 20 (5-30) minutes. More than half of respondents (58%) have dedicated time for reporting. An organised training program was present in most centres (78%), 44% undertake quality assurance, and 79% perform research. Guidelines for performing echocardiography were available in 32 centres (74%). CONCLUSION: Facilities, staffing levels, study times, standards in teaching/training, and quality assurance vary widely across paediatric echocardiography laboratories in Europe. Greater support and investment to facilitate improvements in staffing levels, equipment, and governance would potentially improve European paediatric echocardiography laboratories.

Ascending with ultrasound: telementored eFAST in flight-a feasibility study.

PURPOSE: Teleultrasound uses telecommunication technologies to transmit ultrasound images from a remote location to an expert who guides the acquisition of images and interprets them in real time. Multiple studies have demonstrated the feasibility of teleultrasound. However, its application during helicopter flight using long-term evolution (LTE) for streaming has not been studied. Therefore, we conducted a study to examine the feasibility of teleultrasound in an Airbus H145 helicopter. METHODS: Four anesthesiologists and one military physician were recruited to perform telementored extended Focused Assessment with Sonography in Trauma (eFAST) during nine helicopter flights, each with a unique healthy volunteer. A radiologist was recruited as a remote expert, guiding the physicians in their examinations. The examining physicians reported the user experience of telementored eFAST on a questionnaire, while the remote expert rated the diagnostic quality of the images on a 1-5 Likert scale. In addition, we measured the duration of the examinations and key LTE network parameters including signal strength, quality, and continuity. RESULTS: The images were rated to an average of 4.9 by the remote expert, corresponding to good diagnostic quality. The average duration of telementored eFAST was 05:54 min. LTE coverage was negatively affected by proximity to urban areas and ceased above 2000 ft altitude. Occasional audio problems were addressed by using the Voice over LTE network for communication. The examining physicians unanimously reported on the questionnaire that they would use telementored eFAST on patients. CONCLUSION: Telementored eFAST is feasible in ambulance helicopters and can produce images of good diagnostic quality. However, it relies on stable LTE coverage, which is influenced by many factors, including the helicopter's altitude and flight path. Furthermore, its benefit on patient outcomes remains to be proven.

Circulatory Response to Rapid Volume Expansion and Cardiorespiratory Fitness in Fontan Circulation.

The role of dysfunction of the single ventricle in Fontan failure is incompletely understood. We aimed to evaluate hemodynamic responses to preload increase in Fontan circulation, to determine whether circulatory limitations in different locations identified by experimental preload increase are associated with cardiorespiratory fitness (CRF), and to assess the impact of left versus right ventricular morphology. In 38 consecutive patients (median age = 16.6 years, 16 females), heart catheterization was supplemented with a rapid 5-mL/kg body weight volume expansion. Central venous pressure (CVP), ventricular end-diastolic pressure (VEDP), and peak systolic pressure were averaged for 15‒30 s, 45‒120 s, and 4‒6 min (steady state), respectively. CRF was assessed by peak oxygen consumption (VO2peak) and ventilatory threshold (VT). Median CVP increased from 13 mmHg at baseline to 14.5 mmHg (p < 0.001) at steady state. CVP increased by more than 20% in eight patients. Median VEDP increased from 10 mmHg at baseline to 11.5 mmHg (p < 0.001). Ten patients had elevated VEDP at steady state, and in 21, VEDP increased more than 20%. The transpulmonary pressure difference (CVP‒VEDP) and CVP were consistently higher in patients with right ventricular morphology across repeated measurements. CVP at any stage was associated with VO2peak and VT. VEDP after volume expansion was associated with VT. Preload challenge demonstrates the limitations beyond baseline measurements. Elevation of both CVP and VEDP are associated with impaired CRF. Transpulmonary flow limitation was more pronounced in right ventricular morphology. Ventricular dysfunction may contribute to functional impairment after Fontan operation in young adulthood.ClinicalTrials.gov identifier NCT02378857.

Paediatric and adult congenital cardiology education and training in Europe.

BACKGROUND: Limited data exist on training of European paediatric and adult congenital cardiologists. METHODS: A structured and approved questionnaire was circulated to national delegates of Association for European Paediatric and Congenital Cardiology in 33 European countries. RESULTS: Delegates from 30 countries (91%) responded. Paediatric cardiology was not recognised as a distinct speciality by the respective ministry of Health in seven countries (23%). Twenty countries (67%) have formally accredited paediatric cardiology training programmes, seven (23%) have substantial informal (not accredited or certified) training, and three (10%) have very limited or no programme. Twenty-two countries have a curriculum. Twelve countries have a national training director. There was one paediatric cardiology centre per 2.66 million population (range 0.87-9.64 million), one cardiac surgical centre per 4.73 million population (range 1.63-10.72 million), and one training centre per 4.29 million population (range 1.63-10.72 million population). The median number of paediatric cardiology fellows per training programme was 4 (range 1-17), and duration of training was 3 years (range 2-5 years). An exit examination in paediatric cardiology was conducted in 16 countries (53%) and certification provided by 20 countries (67%). Paediatric cardiologist number is affected by gross domestic product (R2 = 0.41). CONCLUSION: Training varies markedly across European countries. Although formal fellowship programmes exist in many countries, several countries have informal training or no training. Only a minority of countries provide both exit examination and certification. Harmonisation of training and standardisation of exit examination and certification could reduce variation in training thereby promoting high-quality care by European congenital cardiologists.

Cardiovascular Risk Factors are Inversely Associated With Omega-3 Polyunsaturated Fatty Acid Plasma Levels in Pediatric Kidney Transplant Recipients.

OBJECTIVES: High plasma levels of the omega-3 fatty acids eicosapentaenoic acid (EPA), docosahexaenoic acid, and docosapentaenoic acid associates with positive outcomes in adult renal transplant recipients. However, data from pediatric populations are scarce. The aim of the study was to assess the fatty acid profile in a pediatric renal transplantation cohort and to examine the associations between plasma omega-3 fatty acids and cardiovascular disease (CVD) risk factors. METHODS: In this cross-sectional study comprising 53 children (median age, 12.2 years; 32 boys) with a renal transplant, we assessed the prevalence of CVD risk factors as well as markers of end organ damage: carotid intima-media thickness (cIMT) and left ventricular mass index. The associations between plasma omega-3 fatty acids and CVD risk factors were assessed. RESULTS: Twenty-five (47%) patients were preemptively transplanted. Seventy-six percent had dyslipidemia and 51% had hypertension. The mean left ventricular mass index was 40.4 ± 14.3 g/m2.7, and 14% had left ventricular hypertrophy. The mean cIMT was 0.41 ± 0.04 mm. In a multivariate linear regression, EPA levels were inversely associated to blood pressure (ß coeff. = -0.37, P = .007), triglycerides (ß coeff. = -0.44, P = .01), and high-density lipoprotein cholesterol (ß coeff. = -0.41, P = .01). CONCLUSION: EPA levels are inversely associated with components of the metabolic syndrome, which may provide support for specific dietary advice or supplementation in this patient population. cIMT is less pronounced in our cohort than in comparable cohorts with lower rate of preemptive transplantations. Our results need replication in prospective cohorts.

Use of mixed reality for surgery planning: Assessment and development workflow.

Meticulous preoperative planning is an important part of any surgery to achieve high levels of precision and avoid complications. Conventional medical 2D images and their corresponding three-dimensional (3D) reconstructions are the main components of an efficient planning system. However, these systems still use flat screens for visualisation of 3D information, thus losing depth information which is crucial for 3D spatial understanding. Currently, cutting-edge mixed reality systems have shown to be a worthy alternative to provide 3D information to clinicians. In this work, we describe development details of the different steps in the workflow for the clinical use of mixed reality, including results from a qualitative user evaluation and clinical use-cases in laparoscopic liver surgery and heart surgery. Our findings indicate a very high general acceptance of mixed reality devices with our applications and they were consistently rated high for device, visualisation and interaction areas in our questionnaire. Furthermore, our clinical use-cases demonstrate that the surgeons perceived the HoloLens to be useful, recommendable to other surgeons and also provided a definitive answer at a multi-disciplinary team meeting.

T-cell Receptor Excision Circles in Newborns with Heart Defects.

In the fetus, the cardiac neural crest gives rise to both the thymus and the conotruncus of the heart. In newborn screening for severe T-cell lymphopenia neonates with congenital heart defects may be detected. In this study, we investigated the occurrence of T-cell lymphopenia in neonates with or without 22q11.2 deletion syndrome (del) suffering from heart defects. This retrospective cohort study included 125 patients with heart defects. T-cell receptor excision circles (TRECs), a measure for T-cell lymphopenia, were quantified by RT-PCR using stored newborn screening blood spots. Three patient groups were compared: non-conotruncal defects (n = 57), conotruncal defects (n = 42), and 22q11.2 del with conotruncal defects (n = 26). Significantly lower TREC values were detected in patients with 22q11.2 del and conotruncal heart defects compared to those with non-syndromic conotruncal (p < 0.001) and non-conotruncal (p < 0.001) defects. In contrast, no significant difference was found between patients with non-syndromic conotruncal and non-conotruncal heart defects (p = 0.152). Low TREC levels were obtained in neonates treated with heart surgery/intervention within 2 weeks after birth and in those with a fatal outcome (p = 0.02) independent of patient group. A correlation was found between low TREC numbers and oxygen saturation, SpO2 below 95% (p = 0.017). The SpO2 was significantly lower in the non-syndromic conotruncal group compared to non-conotruncal (p < 0.001) and 22q11.2 del group (p = 0.015). No correlation was found between low neonatal TRECs and infections needing hospitalization later in life (p = 0.135). Patients with 22q11.2 del and conotruncal defects have significantly lower TREC levels compared to patients with heart defects without this syndrome.

Use of mixed reality for improved spatial understanding of liver anatomy.

Introduction: In liver surgery, medical images from pre-operative computed tomography and magnetic resonance imaging are the basis for the decision-making process. These images are used in surgery planning and guidance, especially for parenchyma-sparing hepatectomies. Though medical images are commonly visualized in two dimensions (2D), surgeons need to mentally reconstruct this information in three dimensions (3D) for a spatial understanding of the anatomy. The aim of this work is to investigate whether the use of a 3D model visualized in mixed reality with Microsoft HoloLens increases the spatial understanding of the liver, compared to the conventional way of using 2D images.Material and methods: In this study, clinicians had to identify liver segments associated to lesions.Results: Twenty-eight clinicians with varying medical experience were recruited for the study. From a total of 150 lesions, 89 were correctly assigned without significant difference between the modalities. The median time for correct identification was 23.5 [4-138] s using the magnetic resonance imaging images and 6.00 [1-35] s using HoloLens (p < 0.001).Conclusions: The use of 3D liver models in mixed reality significantly decreases the time for tasks requiring a spatial understanding of the organ. This may significantly decrease operating time and improve use of resources.

Mixed reality - new image technology in experimental use. / Blandet virkelighet ­ ny bildeteknologi i klinisk utprøving.

New methods for holographic visualisation provide a true three-dimensional experience of medical images. The technique is generating great interest among surgeons.

In vitro hemodynamic performance of a blood pump for self-powered venous assist in univentricular hearts.

Univentricular heart anomalies represent a group of severe congenital heart defects necessitating early surgical intervention in infancy. The Fontan procedure, the final stage of single-ventricle palliation, establishes a serial connection between systemic and pulmonary circulation by channeling venous return to the lungs. The absence of the subpulmonary ventricle in this peculiar circulation progressively eventuates in failure, primarily due to chronic elevation in inferior vena cava (IVC) pressure. This study experimentally validates the effectiveness of an intracorporeally-powered venous ejector pump (VEP) in reducing IVC pressure in Fontan patients. The VEP exploits a fraction of aortic flow to create a jet-venturi effect for the IVC, negating the external power requirement and driveline infections. An invitro Fontan mock-up circulation loop is developed and the impact of VEP design parameters and physiological conditions is assessed using both idealized and patient-specific total cavopulmonary connection (TCPC) phantoms. The VEP performance in reducing IVC pressure exhibited an inverse relationship with the cardiac output and extra-cardiac conduit (ECC) size and a proportional relationship with the transpulmonary pressure gradient (TPG) and mean arterial pressure (MAP). The ideal VEP with fail-safe features provided an IVC pressure drop of 1.82 ± 0.49, 2.45 ± 0.54, and 3.12 ± 0.43 mm Hg for TPG values of 6, 8, and 10 mm Hg, respectively, averaged over all ECC sizes and cardiac outputs. Furthermore, the arterial oxygen saturation was consistently maintained above 85% during full-assist mode. These results emphasize the potential utility of the VEP to mitigate elevated venous pressure in Fontan patients.

Cardiac resynchronization by repositioning of a ventricular epicardial lead in a patient with hypoplastic left heart syndrome.

Patients with congenital heart disease and univentricular circulation are vulnerable to ventricular dysfunction. In the context of atrioventricular conduction defects, a ventricular pacemaker may be placed, possibly introducing dyssynchronous wall motion and deterioration of ventricular pump function. We describe such a case in which repositioning of the ventricular lead restored synchronicity.

Real-time Remote Expert-guided Echocardiography by Medical Students.

BACKGROUND: Echocardiography is a highly specialised examination performed by experienced healthcare professionals. These experienced healthcare professionals may not be available to patients during all hours in rural healthcare facilities. Remote-guided echocardiography could improve the availability of specialised care for patients living in rural areas. This study examined the feasibility of real-time remote guidance for medical students to perform an echocardiographic assessment of the left side of the heart. Thirteen healthy volunteers were recruited for remote-guided echocardiography, which was performed by 13 medical students. Student examinations/images were compared to reference echocardiography. Measurements of left ventricular fractional shortening and mitral valve blood flow velocity were also compared. Furthermore, guidance through a smartphone videoconference was compared to designated remote guidance software. RESULTS: Two-thirds of the images acquired by students were rated as medium or good quality and usable to evaluate two thirds of the cardiac structures. No significant bias was found for left ventricular fractional shortening. The measurements from the students' exams had a variation coefficient of 14.8% compared to the reference. The calculated deviation of the insonation angle was above 25° for both E and A-wave mitral valve blood flow velocity measurements. Images acquired by guidance through smartphone videoconference were of lower quality than those obtained using the designated remote guidance software. CONCLUSION: Real-time remote-guided echocardiography performed by medical students has limited value for clinical screening but could be useful for educational purposes.

In Silico Evaluation of a Self-powered Venous Ejector Pump for Fontan Patients.

PURPOSE: The Fontan circulation carries a dismal prognosis in the long term due to its peculiar physiology and lack of a subpulmonic ventricle. Although it is multifactorial, elevated IVC pressure is accepted to be the primary cause of Fontan's high mortality and morbidity. This study presents a self-powered venous ejector pump (VEP) that can be used to lower the high IVC venous pressure in single-ventricle patients. METHODS: A self-powered venous assist device that exploits the high-energy aortic flow to lower IVC pressure is designed. The proposed design is clinically feasible, simple in structure, and is powered intracorporeally. The device's performance in reducing IVC pressure is assessed by conducting comprehensive computational fluid dynamics simulations in idealized total cavopulmonary connections with different offsets. The device was finally applied to complex 3D reconstructed patient-specific TCPC models to validate its performance. RESULTS: The assist device provided a significant IVC pressure drop of more than 3.2 mm Hg in both idealized and patient-specific geometries, while maintaining a high systemic oxygen saturation of more than 90%. The simulations revealed no significant caval pressure rise (< 0.1 mm Hg) and sufficient systemic oxygen saturation (> 84%) in the event of device failure, demonstrating its fail-safe feature. CONCLUSIONS: A self-powered venous assist with promising in silico performance in improving Fontan hemodynamics is proposed. Due to its passive nature, the device has the potential to provide palliation for the growing population of patients with failing Fontan.

Systolic myocardial function measured by echocardiographic speckle-tracking and peak oxygen consumption in pediatric childhood cancer survivors-a PACCS study.

Background: Cancer therapy-related cardiotoxicity is a major cause of cardiovascular morbidity in childhood cancer survivors. The aims of this study were to investigate systolic myocardial function and its association to cardiorespiratory fitness in pediatric childhood cancer survivors. Methods: In this sub-study of the international study "Physical Activity and fitness in Childhood Cancer Survivors" (PACCS), echocardiographic measures of left ventricular global longitudinal strain (LV-GLS) and right ventricular longitudinal strain (RV-LS) were measured in 128 childhood cancer survivors aged 9-18 years and in 23 age- and sex-matched controls. Cardiorespiratory fitness was measured as peak oxygen consumption achieved on treadmill and correlated to myocardial function. Results: Mean LV-GLS was reduced in the childhood cancer survivors compared to the controls, -19.7% [95% confidence interval (CI) -20.1% to -19.3%] vs. -21.3% (95% CI: -22.2% to -20.3%) (p = 0.004), however, mainly within normal range. Only 13% of the childhood cancer survivors had reduced LV longitudinal strain z-score. Mean RV-LS was similar in the childhood cancer survivors and the controls, -23.2% (95% CI: -23.7% to -22.6%) vs. -23.3% (95% CI: -24.6% to -22.0%) (p = 0.8). In the childhood cancer survivors, lower myocardial function was associated with lower peak oxygen consumption [correlation coefficient (r) = -0.3 for LV-GLS]. Higher doses of anthracyclines (r = 0.5 for LV-GLS and 0.2 for RV-LS) and increasing time after treatment (r = 0.3 for LV-GLS and 0.2 for RV-LS) were associated with lower myocardial function. Conclusions: Left ventricular function, but not right ventricular function, was reduced in pediatric childhood cancer survivors compared to controls, and a lower left ventricular myocardial function was associated with lower peak oxygen consumption. Furthermore, higher anthracycline doses and increasing time after treatment were associated with lower myocardial function, implying that long-term follow-up is important in this population at risk.

Myocardial longitudinal peak systolic acceleration (pSac): relationship to ejection phase, pressure, and contractility.

Acceleration has been measured both noninvasively and invasively, during both isovolumic contraction and early ejection and has been shown to reflect contractility, especially through correlation with dP/dt(max) . In this study timing and amplitude of mitral valve annulus acceleration assessed by tissue Doppler were measured and related to diastolic and systolic events. Invasive load independent measures of contractility, based on pressure-volume relationships, were derived, and pacing was done to modulate and control heart rate. Peak systolic acceleration (pSac) of the mitral valve annulus was shown to occur slightly later but timely related to dP/dt(max) (P < 0.05), while peak preejection acceleration (pPac) was related to diastolic events. During inotropy and preload modulation dP/dt(max) was found to be the strongest determinant of pSac (ß= 0.9 ± 0.1; P < 0.001 and ß= 1.3 ± 0.4; P < 0.001, respectively, log-transformed variables). PSac increased with pacing at a higher rate (ß= 0.1 ± 0.0 cm/sec(2), P = 0.03). Furthermore, pSac indexed to end-diastolic volume (EDV) was linearly correlated to load independent contractility parameters (E(max), R = 0.7; ESPVR, R = 0.7; and PRSW, R = 0.5), and proved stable toward changes in preload and afterload. The relation between dP/dt(max)/EDV and pSac/EDV was stable throughout the study. In conclusion we found that peak systolic longitudinal acceleration (pSac) of the mitral valve annulus during aortic valve opening is strongly associated with dP/dt(max). Indexed to EDV, pSac may represent a load independent noninvasive contractility parameter. We consider pSac a candidate marker of long-axis contractility which should be viewed upon as the long-axis contribution to dP/dt(max).

Mechanisms of exercise-induced pulmonary hypertension in patients with cardiac septal defects.

The objective of this study was to investigate mechanisms of exercise-induced pulmonary hypertension in patients with congenital cardiac septal defects. This was a randomized, placebo controlled, crossover drug trial in a single national pediatric cardiology centre that performs congenital cardiac defect surgery. There were 14 patients with cardiac septal defects and known exercise-induced pulmonary hypertension. The intervention consisted of 50 mg oral sildenafil versus placebo. Measurements included supine bicycle exercise echocardiography and oxygen uptake. The outcome measure was right-ventricular systolic pressure as estimated by Doppler tracings of tricuspid regurgitant jet as well as systolic and diastolic longitudinal myocardial velocities by color tissue Doppler echocardiography. Sildenafil did not change exercise right-ventricular systolic pressure during exercise; however, decreased systemic systolic pressure was seen. Enhanced biventricular longitudinal function with sildenafil compared with placebo was indicated by greater tissue Doppler velocities and displacement measurements during exercise. Finally, a less steep increase of right-ventricular pressure during exercise was associated with greater left-ventricular diastolic myocardial tissue Doppler velocity. Exercise-induced pulmonary hypertension in cardiac septal defects does not seem to have a pulmonary vasoconstrictive component, but it may be related to left-ventricular filling pressure. Furthermore, sildenafil improved biventricular systolic performance in this patient group, possibly related to decreased systemic afterload.

Current outcomes of live-born children with double outlet right ventricle in Norway.

OBJECTIVES: This population-based, comprehensive, retrospective study presented the clinical outcomes of all children born in Norway between 2003 and 2017 with double outlet right ventricle (DORV). METHODS: All children born with DORV between 2003 and 2017 were identified in the Oslo University Hospital registry. Patients' characteristics, interventions, complications and deaths were recorded. Echocardiographic data were reviewed for classification according to current standards. We investigated time-dependent surgical reintervention and mortality using Kaplan-Meier analyses and determinants of treatment complications, reintervention and death using regression analyses. RESULTS: Ninety-three children with DORV represented an annual median prevalence of 1.18 per 10 000 births in Norway. Six children received palliative care. With an intention to treat, a surgical route with the primary biventricular repair was followed for 62 children, staged biventricular repair for 15 and univentricular repair for 10 children. Major complications occurred in 1.0% and 6.2% of children following catheter or surgical intervention, respectively. No significant determinants of the complications were identified. Overall survival following treatment was 91.9%, 90.8%, 89.5% and 89.5% and corresponding freedom from surgical reintervention was 88.0%, 79.0%, 74.9% and 69.4% at 1, 2, 5 and 10 years, respectively. The presence of atrioventricular septal defect predicted an increased risk of mortality (hazard ratio: 7.16) but did not increase the risk of surgical reintervention. CONCLUSIONS: In Norway, most children receive tailored treatment for DORV with low rates of complications, surgical reinterventions and mortality. However, atrioventricular septal defect remains a potential determinant of postoperative death.

Towards Autonomous Robotic Biopsy-Design, Modeling and Control of a Robot for Needle Insertion of a Commercial Full Core Biopsy Instrument.

This paper presents the design, control, and experimental evaluation of a novel fully automated robotic-assisted system for the positioning and insertion of a commercial full core biopsy instrument under guidance by ultrasound imaging. The robotic system consisted of a novel 4 Degree of freedom (DOF) add-on robot for the positioning and insertion of the biopsy instrument that is attached to a UR5-based teleoperation system with 6 DOF. The robotic system incorporates the advantages of both freehand and probe-guided biopsy techniques. The proposed robotic system can be used as a slave robot in a teleoperation configuration or as an autonomous or semi-autonomous robot in the future. While the UR5 manipulator was controlled using a teleoperation scheme with force controller, a reinforcement learning based controller using the Deep Deterministic Policy Gradient (DDPG) algorithm was developed for the add-on robotic system. The dexterous workspace analysis of the add-on robotic system demonstrated that the system has a suitable workspace within the US image. Two sets of comprehensive experiments including four experiments were performed to evaluate the robotic system's performance in terms of the biopsy instrument positioning, and the insertion of the needle inside the ultrasound plane. The experimental results showed the ability of the robotic system for in-plane needle insertion. The overall mean error of all four experiments in the tracking of the needle angle was 0.446°, and the resolution of the needle insertion was 0.002 mm.