Emanuela R. Valsangiacomo Buechel

Guidelines and protocols for cardiovascular magnetic resonance in children and adults with congenital heart disease: SCMR expert consensus group on congenital heart disease.

Cardiovascular magnetic resonance (CMR) has taken on an increasingly important role in the diagnostic evaluation and pre-procedural planning for patients with congenital heart disease. This article provides guidelines for the performance of CMR in children and adults with congenital heart disease. The first portion addresses preparation for the examination and safety issues, the second describes the primary techniques used in an examination, and the third provides disease-specific protocols. Variations in practice are highlighted and expert consensus recommendations are provided. Indications and appropriate use criteria for CMR examination are not specifically addressed.

Normal right- and left ventricular volumes and myocardial mass in children measured by steady state free precession cardiovascular magnetic resonance

BackgroundQuantification of ventricular volume by Steady State Free Precession (SSFP) cardiovascular magnetic resonance is accurate and reproducible. Normal values exist for adults, but are lacking for children.We sought to establish normal values for left and right ventricular volumes, mass and function in healthy children by using SSFP.Methods and resultsFifty children (27 females, 23 males) without cardiovascular disease were evaluated. Median age was 11 years (range 7 months – 18 years), weight 35 kg (range 7–77 kg), height 146 cm (range 66–181 cm). Thirty-six examinations were performed with breath holding, 14 in freely breathing sedated children.Ventricular volumes and mass were measured in the end systolic and end diastolic phase on SSFP cine images acquired in a short axis plane as a stack of 12 contiguous slices covering full length of both ventricles.Regression analysis showed an exponential relationship between body surface area (BSA) and ventricular volumes and mass (normal value = a*BSAb). Normative curves for males and females are presented in relation to BSA for the enddiastolic volume, endsystolic volume and mass of both ventricles. Intra- and interobserver variability of the measurements was within the limits of 2% and 7% respectively, except for right ventricular mass (10%).ConclusionThe exponential equation for calculation of normal values for each ventricular parameter and graphical display of normative curves for data acquired in healthy children by SSFP cardiovascular magnetic resonance are provided.

Imaging the right heart: the use of integrated multimodality imaging

During recent years, right ventricular (RV) structure and function have been found to be an important determinant of outcome in different cardiovascular and also pulmonary diseases. Currently, echocardiography and cardiac magnetic resonance (CMR) imaging are the two imaging modalities most commonly used to visualize the RV. Most structural abnormalities of the RV can be reliably described by echocardiography but due its complex geometrical shape, echocardiographic assessment of RV function is more challenging. Newer promising echocardiographic techniques are emerging but lack of validation and limited normal reference data influence their routine clinical application. Cardiac magnetic resonance is generally considered the clinical reference technique due to its unlimited imaging planes, superior image resolution, and three-dimensional volumetric rendering. The accuracy and reliability of CMR measurements make it the ideal tool for serial examinations of RV function. Multidetector computed tomography (MDCT) plays an important role in the diagnosis of pulmonary emboli but can also be used for assessing RV ischaemic disease or as an alternative for CMR if contra-indicated. Radionuclide techniques have become more obsolete in the current era. The different imaging modalities should be considered complimentary and each plays a role for different indications.

Characterization of cardiac tumors in children by cardiovascular magnetic resonance imaging: a multicenter experience.

OBJECTIVES The aim of this study was to report the results of an international multicenter experience of cardiac magnetic resonance imaging (MRI) evaluation of cardiac tumors in children, each with histology correlation or a diagnosis of tuberous sclerosis, and to determine which characteristics are predictive of tumor type. BACKGROUND Individual centers have relatively little experience with diagnostic imaging of cardiac tumors in children, because of their low prevalence. The accuracy of cardiac MRI diagnosis on the basis of a pre-defined set of criteria has not been tested. METHODS An international group of pediatric cardiac imaging centers was solicited for case contribution. Inclusion criteria comprised: 1) age at diagnosis ≤18 years; 2) cardiac MRI evaluation of cardiac tumor; and 3) histologic diagnosis or diagnosis of tuberous sclerosis. Data from the cardiac MRI images were analyzed for mass characteristics. On the basis of pre-defined cardiac MRI criteria derived from published data, 3 blinded investigators determined tumor type, and their consensus diagnoses were compared with histologic diagnoses. RESULTS Cases (n = 78) submitted from 15 centers in 4 countries had the following diagnoses: fibroma (n = 30), rhabdomyoma (n = 14), malignant tumor (n = 12), hemangioma (n = 9), thrombus (n = 4), myxoma (n = 3), teratoma (n = 2), and paraganglioma, pericardial cyst, Purkinje cell tumor, and papillary fibroelastoma (n = 1, each). Reviewers who were blinded to the histologic diagnoses correctly diagnosed 97% of the cases but included a differential diagnosis in 42%. Better image quality grade and more complete examination were associated with higher diagnostic accuracy. CONCLUSIONS Cardiac MRI can predict the likely tumor type in the majority of children with a cardiac mass. A comprehensive imaging protocol is essential for accurate diagnosis. However, histologic diagnosis remains the gold standard, and in some cases malignancy cannot be definitively excluded on the basis of cardiac MRI images alone.

Health-Related Quality of Life in Children and Adolescents after Open-Heart Surgery

OBJECTIVE To assess health-related quality of life (HRQOL) in children with congenital heart disease (CHD) after open-heart surgery and to identify medical, individual, and family-related predictors of outcome. STUDY DESIGN Cross-sectional cohort study. 155 children with CHD (40% cyanotic type) who underwent open-heart surgery between 1995 and 1998 were eligible. One hundred and ten patients (response rate 71%) were investigated at a mean age of 10.4 years. Mean age at operation was 2.3 years (range, 0-8.7 years), mean duration of cardiopulmonary bypass was 95 minutes (range, 5-206 minutes), and circulatory arrest was performed in 9% of the children. Child- and parent-rated HRQOL was evaluated by the TNO-AZL Child Quality of Life Questionnaire. Scores were compared with healthy references. RESULTS Most dimensions of self-reported HRQOL were impaired, including autonomy and motor, social, and emotional functioning. In addition to the childrens ratings, parents rated cognitive functioning of their children as diminished. Multivariate analyses revealed that duration of cardiopulmonary bypass, length of hospitalization, need for current cardiac medication, and adverse family relationships had a negative impact on parent- but not on child-rated HRQOL. CONCLUSIONS HRQOL is impaired in children with CHD after open-heart surgery. Medical variables and the quality of family relationships are important determinants.

Left ventricular non-compaction: prevalence in congenital heart disease.

INTRODUCTION Left ventricular non-compaction cardiomyopathy (LVNC) is a rare cardiomyopathy, originally described as an isolated disease without other structural cardiac abnormalities. The aim of this study was to explore the prevalence of LVNC among adults with different types of congenital heart disease. METHODS From our databases we identified adults with congenital heart disease who fulfilled diagnostic criteria for LVNC. We report frequencies of associated congenital cardiac defects and the prevalence of LVNC among patients with different congenital heart defects. RESULTS From a total of 202 patients with LVNC, 24 patients (12%; mean age 32 ± 11 years, 19 males) had additional congenital cardiac defects. Associated defects were left ventricular outflow tract abnormalities in 11 patients (46%), including 7 uni- or bicuspid aortic valves; two aortic coarctations; one diffuse aortic hypoplasia and one subaortic stenosis, Ebstein anomaly in 6 patients (25%), tetralogy of Fallot in two (8%), and double outlet right ventricle in one patient (4%). In our cohort, the prevalence of LVNC was highest among patients with Ebstein anomaly (6/40, 15%), followed by aortic coarctation (2/60, 3%), tetralogy of Fallot (3/129, 2%) and uni- or bicuspid aortic valves (7/963, 1%). CONCLUSION In adults, various forms of congenital heart disease are associated with LVNC, particularly stenotic lesions of the left ventricular outflow tract, Ebstein anomaly, and tetralogy of Fallot. In the future, studying these patients in more depth may provide a better understanding of the interplay between genetic and hemodynamic factors that lead to the phenotype of LVNC.

Normal values for aortic diameters in children and adolescents – assessment in vivo by contrast-enhanced CMR-angiography

BackgroundContrast-enhanced CMR angiography (CE-CMRA) is being increasingly used for diagnosing aortic arch anomalies, planning interventions and follow-up assessment. We sought to establish normal values for the diameters of the thoracic aorta and reference curves related to body growth in children using CE-CMRA.ResultsCE-CMRA was performed in 53 children without cardiovascular disease. The median age was 9 years (range 2 – 20 years), weight 30 kg (range 12 – 75 kg), height 131 cm (range 81 – 184 cm), body surface area (BSA) 1.05 m2 (range 0.52–1.9 m2). Aortic diameters were measured at nine standardized sites on oblique maximum-intensity projection (MIP) images. Regression analysis of diameters in relation to BSA demonstrated linear relationship between the cross-sectional aortic diameters and the square root of BSA (BSA0.5). Normative diameters were (0.57 + 19.37*BSA0.5) mm for the aortic sinus, (-3.52 + 18.66*BSA0.5) mm for the first segment of the aortic arch, (-3.37 + 16.52*BSA0.5) mm for the isthmic region and (-1.27 + 9.89*BSA0.5) mm for the descending aorta at the level of the diaphragm. Normative curves are presented.ConclusionThis study provides normative values for aortic diameters in children measured by CE-CMRA. These data may serve for making the diagnosis of pediatric arch anomalies, assessing the need for treatment and planning interventions.

Modified Blalock Taussig shunt: a not-so-simple palliative procedure

OBJECTIVES Thirty-two consecutive isolated modified Blalock Taussig (BT) shunts performed in infancy since 2004 were reviewed and analysed to identify the risk factors for shunt intervention and mortality. METHODS Sternotomy was the only approach used. Median age and weight were 10.5 (range 1-74) days and 2.9 (1.9-4.4) kg, respectively. Shunt palliation was performed for biventricular hearts (Tetralogy of Fallot/double outlet right ventricle/transposition of great arteries_ventricular septal defect_pulmonary stenosis/pulmonary atresia_ventricular septal defect/others) in 21, and univentricular hearts in 11, patients. Hypoplastic left heart syndrome patients were excluded. Two procedures required cardiopulmonary bypass. Median shunt size was 3.5 (3-4) mm and median shunt size/kg body weight was 1.2 (0.9-1.7) mm/kg. Reduction in shunt size was necessary in 5 of 32 (16%) patients. RESULTS Three of 32 (9%) patients died after 3 (1-15) days due to cardiorespiratory decompensation. Lower body weight (P = 0.04) and bigger shunt size/kg of body weight (P = 0.004) were significant risk factors for mortality. Acute shunt thrombosis was observed in 3 of 32 (9%), none leading to death. Need for cardiac decongestive therapy was associated with univentricular hearts (P < 0.001), bigger shunt size (P = 0.054) and longer hospital stay (P = 0.005). Twenty-eight patients have undergone a successful shunt takedown at a median age of 5.5 (0.5-11.9) months, without late mortality. CONCLUSIONS Palliation with a modified BT shunt continues to be indicated despite increased thrust on primary corrective surgery. Though seemingly simple, it is associated with significant morbidity and mortality. Effective over-shunting and acute shunt thrombosis are the lingering problems of shunt therapy.

Feasibility of perfusion cardiovascular magnetic resonance in paediatric patients

AimsAs coronary artery disease may also occur during childhood in some specific conditions, we sought to assess the feasibility and accuracy of perfusion cardiovascular magnetic resonance (CMR) in paediatric patients.Methods and resultsFirst-pass perfusion CMR studies were performed under pharmacological stress with adenosine and by using a hybrid echo-planar pulse sequence with slice-selective saturation recovery preparation. Fifty-six perfusion CMR examinations were performed in 47 patients. The median age was 12 years (1 month-18 years), and weight 42.8 kg (2.6-82 kg). General anaesthesia was required in 18 patients. Mean examination time was 67 ± 19 min. Diagnostic image quality was obtained in 54/56 examinations. In 23 cases the acquisition parameters were adapted to patients size. Perfusion CMR was abnormal in 16 examinations. The perfusion defects affected the territory of the left anterior descending coronary artery in 11, of the right coronary artery in 3, and of the circumflex coronary artery in 2 cases. Compared to coronary angiography, perfusion CMR showed a sensitivity of 87% (CI 52-97%) and a specificity of 95% (CI 79-99%).ConclusionIn children, perfusion CMR is feasible and accurate. In very young children (less than 1 year old), diagnostic image quality may be limited.

Accuracy of Knowledge-Based Reconstruction for Measurement of Right Ventricular Volume and Function in Patients With Tetralogy of Fallot

We tested the accuracy and reproducibility of knowledge-based reconstruction (KBR) for measuring right ventricular (RV) volume and function. KBR enables rapid assessment of the right ventricle from sparse user input by referencing a database. KBR generates a 3-dimensional surface to fit points that the user enters at anatomic landmarks. We measured the RV volume using KBR from magnetic resonance images in 20 patients with repaired tetralogy of Fallot at end-diastole and end-systole. We entered points in the long- and short-axis and/or oblique views. The true volume was computed by manually tracing the RV borders for 3-dimensional reconstruction using the piecewise smooth subdivision surface method. The reference database included 54 patients with tetralogy of Fallot patients. The KBR values agreed closely with the true values for the end-diastolic volume (r = 0.993), end-systolic volume (r = 0.992), and ejection fraction (EF; r = 0.930). KBR slightly overestimated the end-diastolic volume (4 +/- 10 ml, p = NS), end-systolic volume (1 +/- 9 ml, p = NS), and EF (4 +/- 3%, p = NS). No bias in the error was found by Bland-Altman analysis (p = NS for end-diastolic and end-systolic volume and EF). The KBR volumes had approached the true volumes (235 +/- 93 vs 243 +/- 93, p = 0.012, r = 0.978 for end-diastolic and end-systolic volumes combined) already after the first run and the entry of 19 +/- 3 points. In conclusion, KBR provided accurate measurement of the RV volume and EF with minimal user input. KBR is a clinically feasible alternative to full manual tracing of the heart borders from imaging data.