Unusual Vascular Ring in the Fetus.

We present the clinical course and echocardiographic and genetic findings of two fetuses with an unusual vascular ring, created by a left aortic arch with a right arterial duct and an aberrant right subclavian artery. One fetus was diagnosed with 22q11.2 microdeletion and the other became symptomatic in infancy. It is important to consider the position of the arterial ductal ligament in patients who present with tracheoesophageal compressive symptoms in the presence of a left aortic arch. These cases also highlight that a vascular ring formed from a left arch may have similar associations to a vascular ring formed by a right aortic arch.

A Uniform Description of Perioperative Brain MRI Findings in Infants with Severe Congenital Heart Disease: Results of a European Collaboration.

BACKGROUND AND PURPOSE: A uniform description of brain MR imaging findings in infants with severe congenital heart disease to assess risk factors, predict outcome, and compare centers is lacking. Our objective was to uniformly describe the spectrum of perioperative brain MR imaging findings in infants with congenital heart disease. MATERIALS AND METHODS: Prospective observational studies were performed at 3 European centers between 2009 and 2019. Brain MR imaging was performed preoperatively and/or postoperatively in infants with transposition of the great arteries, single-ventricle physiology, or left ventricular outflow tract obstruction undergoing cardiac surgery within the first 6 weeks of life. Brain injury was assessed on T1, T2, DWI, SWI, and MRV. A subsample of images was assessed jointly to reach a consensus. RESULTS: A total of 348 MR imaging scans (180 preoperatively, 168 postoperatively, 146 pre- and postoperatively) were obtained in 202 infants. Preoperative, new postoperative, and cumulative postoperative white matter injury was identified in 25%, 30%, and 36%; arterial ischemic stroke, in 6%, 10%, and 14%; hypoxic-ischemic watershed injury in 2%, 1%, and 1%; intraparenchymal cerebral hemorrhage, in 0%, 4%, and 5%; cerebellar hemorrhage, in 6%, 2%, and 6%; intraventricular hemorrhage, in 14%, 6%, and 13%; subdural hemorrhage, in 29%, 17%, and 29%; and cerebral sinovenous thrombosis, in 0%, 10%, and 10%, respectively. CONCLUSIONS: A broad spectrum of perioperative brain MR imaging findings was found in infants with severe congenital heart disease. We propose an MR imaging protocol including T1-, T2-, diffusion-, and susceptibility-weighted imaging, and MRV to identify ischemic, hemorrhagic, and thrombotic lesions observed in this patient group.

Synergy in the heart: RV systolic function plays a key role in optimizing LV performance during exercise.

The right ventricle (RV) is often overlooked in the evaluation of cardiac performance and treatment of left ventricular (LV) heart diseases. However, recent evidence suggests the RV may play an important role in maintaining systemic cardiac function and delivering stroke volume (SV). We used exercise cardiac magnetic resonance and biomechanical modeling to investigate the role of the RV in LV stroke volume regulation. We studied SV augmentation during exercise by pharmacologically inducing negative chronotropy (sHRi) in healthy volunteers and investigating training-induced SV augmentation in endurance athletes. SV augmentation during exercise after sHRi is achieved differently in the two ventricles. In the RV, the larger SV is driven by increasing contraction down to lower end-systolic volume (ESV; P < 0.001). In the LV, SV augmentation is achieved through an increase in end-diastolic volume (EDV; P < 0.001), avoiding contraction to a lower ESV. The same mechanism underlies the enhanced SV response observed in athletes. Changes in atrial area during SV augmentation suggest that the improved LV EDV response is sustained by the larger RV contractions. Using our biomechanical model, we explain this behavior by showing that the RV systolic function-driven regulation of LV SV optimizes the energetic cost of LV contraction and leads to minimization of the total costs of biventricular contraction. In conclusion, this work provides mechanistic understanding of the pivotal role of the RV in optimizing LV SV during exercise. It demonstrates why optimizing RV function needs to become a key part of therapeutic strategies in patients and training for athletes.NEW & NOTEWORTHY The right ventricle appears to have an important impact on maintaining systemic cardiac function and delivering stroke volume. However, its exact role in supporting left ventricular function has so far been unclear. This study demonstrates a new mechanism of ventricular interaction that provides mechanistic understanding of the key importance of the right ventricle in driving cardiac performance.

A novel methodology for personalized simulations of ventricular hemodynamics from noninvasive imaging data.

Current state-of-the-art imaging techniques can provide quantitative information to characterize ventricular function within the limits of the spatiotemporal resolution achievable in a realistic acquisition time. These imaging data can be used to personalize computer models, which in turn can help treatment planning by quantifying biomarkers that cannot be directly imaged, such as flow energy, shear stress and pressure gradients. To date, computer models have typically relied on invasive pressure measurements to be made patient-specific. When these data are not available, the scope and validity of the models are limited. To address this problem, we propose a new methodology for modeling patient-specific hemodynamics based exclusively on noninvasive velocity and anatomical data from 3D+t echocardiography or Magnetic Resonance Imaging (MRI). Numerical simulations of the cardiac cycle are driven by the image-derived velocities prescribed at the model boundaries using a penalty method that recovers a physical solution by minimizing the energy imparted to the system. This numerical approach circumvents the mathematical challenges due to the poor conditioning that arises from the imposition of boundary conditions on velocity only. We demonstrate that through this technique we are able to reconstruct given flow fields using Dirichlet only conditions. We also perform a sensitivity analysis to investigate the accuracy of this approach for different images with varying spatiotemporal resolution. Finally, we examine the influence of noise on the computed result, showing robustness to unbiased noise with an average error in the simulated velocity approximately 7% for a typical voxel size of 2mm(3) and temporal resolution of 30ms. The methodology is eventually applied to a patient case to highlight the potential for a direct clinical translation.

Prenatal diagnosis of left ventricular diverticulum and coarctation of the aorta.

Congenital left ventricular diverticulum (LVD) is a rare abnormality of the myocardium which has been detected previously in the fetus. Lesions have been reported from as early as 12 weeks' gestation but are more commonly detected in the mid-second trimester. Fetal presentation of LVD ranges from an abnormal four-chamber view of the heart, arrhythmia or isolated pericardial effusion to fetal hydrops with associated heart failure. Here, we describe the prenatal diagnosis of an infant with LVD originating from the left ventricular outflow tract associated with coarctation of the aorta. The diagnosis was confirmed postnatally by two-dimensional echocardiography and cardiac magnetic resonance imaging. We hypothesize that the lesion compromised antegrade flow into the transverse aortic arch, which may have contributed to underdevelopment of the aortic arch and subsequently the development of coarctation of the aorta. This is a unique case of LVD and coarctation of the aorta.

Towards a fast and efficient approach for modelling the patient-specific ventricular haemodynamics.

Computer modelling of the heart has emerged over the past decade as a powerful technique to explore the cardiovascular pathophysiology and inform clinical diagnosis. The current state-of-the-art in biophysical modelling requires a wealth of, potentially invasive, clinical data for the parametrisation and validation of the models, a process that is still too long and complex to be compatible with the clinical decision-making time. Therefore, there remains a need for models that can be quickly customised to reconstruct physical processes difficult to measure directly in patients. In this paper, we propose a less resource-intensive approach to modelling, whereby computational fluid-dynamics (CFD) models are constrained exclusively by boundary motion derived from imaging data through a validated wall tracking algorithm. These models are generated and parametrised based solely on ultrasound data, whose acquisition is fast, inexpensive and routine in all patients. To maximise the time and computational efficiency, a semi-automated pipeline is embedded in an image processing workflow to personalise the models. Applying this approach to two patient cases, we demonstrate this tool can be directly used in the clinic to interpret and complement the available clinical data by providing a quantitative indication of clinical markers that cannot be easily derived from imaging, such as pressure gradients and the flow energy.

Three-dimensional fetal echocardiography for prediction of postnatal surgical approach in double outlet right ventricle: a pilot study.

OBJECTIVES: To examine the feasibility of reconstructing three-dimensional (3D) echocardiographic views in fetuses with double outlet right ventricle, which might enhance prognostication with respect to the postnatal surgical approach. METHODS: This was a retrospective blinded observational study. Our database was reviewed from January 2007 to June 2011 to identify fetuses with usual atrial arrangement, concordant atrioventricular connections, double outlet right ventricle and relatively balanced left and right ventricular size. Six fetuses, in which there was an intention to treat, were included. RESULTS: In all six cases, we identified important features, including location of the ventricular septal defect and its relation to the atrioventricular valves and great arteries. The postnatal surgical approach was predicted accurately in each case. CONCLUSION: In this group of fetuses with double outlet right ventricle, detailed evaluation by 3D fetal echocardiography enhanced visualization of the anatomy, leading to accurate prediction of the type of surgical repair. Prospective validation in a large cohort of fetuses is warranted.

Managed Care Network for the assessment of cardiac problems in children in a district general hospital: a working model.

AIM: To assess a model for cardiology assessments in children with suspected heart disease by a general paediatrician with special expertise in paediatric cardiology (PsePC) in a district general hospital. METHODS: A new monthly "screening" clinic was established in May 2004 by the PsePC to reduce the burden of new referrals on outreach tertiary paediatric cardiology services. All patients were to have echocardiograms as part of their referral for cardiac assessment. Over a one year period (May 2004-April 2005), through audit, details of referrers, indications for referral, echocardiography assessments, and subsequent management were recorded. This was compared with the pattern of patients seen in the joint paediatric cardiology outreach clinics over a two year period (May 2003-April 2005). RESULTS: In the "screening" clinic, there were 75 appointments for 65 patients seen in 12 months. Fifty five of these patients had normal echocardiographic studies. Of the 47 referrals with heart murmurs in asymptomatic children, four had structurally abnormal hearts on echocardiographic assessment. Between May-October 2003 and November 2003-April 2004, the number of new patients with normal echocardiographic studies seen in the paediatric cardiology outreach clinic was 33/106 (31%) and 28/110 (25.4%) respectively. Following the introduction of the "screening" clinic, the number decreased to 21/99 (21%) during May-October 2004, and 10/102 (9.8%) during November 2004-April 2005. CONCLUSION: This model can work effectively in order to identify pathology requiring input of a paediatric cardiologist more appropriately. Paediatricians with specific training in paediatric cardiology are potentially well equipped to provide this basic screening service.