Clinical history and management recommendations of the smooth muscle dysfunction syndrome due to ACTA2 arginine 179 alterations.

PURPOSE: Smooth muscle dysfunction syndrome (SMDS) due to heterozygous ACTA2 arginine 179 alterations is characterized by patent ductus arteriosus, vasculopathy (aneurysm and occlusive lesions), pulmonary arterial hypertension, and other complications in smooth muscle-dependent organs. We sought to define the clinical history of SMDS to develop recommendations for evaluation and management. METHODS: Medical records of 33 patients with SMDS (median age 12 years) were abstracted and analyzed. RESULTS: All patients had congenital mydriasis and related pupillary abnormalities at birth and presented in infancy with a patent ductus arteriosus or aortopulmonary window. Patients had cerebrovascular disease characterized by small vessel disease (hyperintense periventricular white matter lesions; 95%), intracranial artery stenosis (77%), ischemic strokes (27%), and seizures (18%). Twelve (36%) patients had thoracic aortic aneurysm repair or dissection at median age of 14 years and aortic disease was fully penetrant by the age of 25 years. Three (9%) patients had axillary artery aneurysms complicated by thromboembolic episodes. Nine patients died between the ages of 0.5 and 32 years due to aortic, pulmonary, or stroke complications, or unknown causes. CONCLUSION: Based on these data, recommendations are provided for the surveillance and management of SMDS to help prevent early-onset life-threatening complications.

Improved high-resolution pediatric vascular cardiovascular magnetic resonance with gadofosveset-enhanced 3D respiratory navigated, inversion recovery prepared gradient echo readout imaging compared to 3D balanced steady-state free precession readout imaging.

BACKGROUND: Improved delineation of vascular structures is a common indication for cardiovascular magnetic resonance (CMR) in children and requires high spatial resolution. Currently, pre-contrast 3D, respiratory navigated, T2-prepared, fat saturated imaging with a bSSFP readout (3D bSSFP) is commonly used; however, these images can be limited by blood pool inhomogeneity and exaggeration of metal artifact. We compared image quality of pediatric vasculature obtained using standard 3D bSSFP to 3D, respiratory navigated, inversion recovery prepared imaging with a gradient echo readout (3D IR GRE) performed after administration of gadofosveset trisodium (GT), a blood pool contrast agent. METHODS: For both sequences, VCG triggering was used with acquisition during a quiescent period of the cardiac cycle. 3D bSSFP imaging was performed pre-contrast, and 3D IR GRE imaging was performed 5 min after GT administration. We devised a vascular imaging quality score (VIQS) with subscores for coronary arteries, pulmonary arteries and veins, blood pool homogeneity, and metal artifact. Scoring was performed on axial reconstructions of isotropic datasets by two independent readers and differences were adjudicated. Signal- and contrast-to-noise (SNR and CNR) calculations were performed on each dataset. RESULTS: Thirty-five patients had both 3D bSSFP and 3D IR GRE imaging performed. 3D IR GRE imaging showed improved overall vascular imaging compared to 3D bSSFP when comparing all-patient VIQS scores (n = 35, median 14 (IQR 11-15), vs 6 (4-10), p < 0.0001), and when analyzing the subset of patients with intrathoracic metal (n = 17, 16 (14-17) vs. 5 (2-9), p < 0.0001). 3D IR GRE showed significantly improved VIQS subscores for imaging the RCA, pulmonary arteries, pulmonary veins, and blood pool homogeneity. In addition, 3D IR GRE imaging showed reduced variability in both all-patient and metal VIQS scores compared to 3D bSSFP (p < 0.05). SNR and CNR were higher with 3D IR GRE in the left ventricle and left atrium, but not the pulmonary arteries. CONCLUSIONS: Respiratory navigated 3D IR GRE imaging after GT administration provides improved vascular CMR in pediatric patients compared to pre-contrast 3D bSSFP imaging, as well as improved imaging in patients with intrathoracic metal. It is an excellent alternative in this challenging patient population when high spatial resolution vascular imaging is needed.

Late primary transplantation in complex congenital heart disease.

Heart transplantation is a viable option for patients with congenital heart disease who manifest heart failure, predominantly post-surgical palliation. We present a case of complex congenital heart disease, where surgical palliation was considered not to be an option. Considerate medical management with close follow-up allowed for a nine-yr delay until eventual successful heart transplantation. The case also highlights the natural history over nine yr of the effects of right ventricular outflow tract obstruction on the left ventricular remodeling which is analogous to a PA banding in patients with dilated cardiomyopathy.

Severe aortopathy due to fibulin-4 deficiency: molecular insights, surgical strategy, and a review of the literature.

UNLABELLED: Mutations in the EFEMP2 (alias FBLN4) gene, which encodes the extracellular matrix protein fibulin-4, lead to severe aortopathy with aneurysm formation and vascular tortuosity. The disease phenotype, termed autosomal recessive cutis laxa type 1B (ARCL 1B), is rare among heritable connective tissue diseases but becomes more likely when noting family consanguinity and loose, inelastic skin in the patient. Our patient presented with an intercurrent illness exacerbating upper airway obstruction due to compression from a large aortic aneurysm. Genetic testing eventually revealed the causative mutation. She was initially treated with an angiotensin II receptor blocker and beta-blocker and eventually underwent total thoracic aortic replacement via a two-stage elephant trunk-type procedure. She recovered well and is currently asymptomatic but will require lifetime follow-up due to residual vascular tortuosity and aneurysm risk. CONCLUSION: Better understanding of the importance of transforming growth factor beta signaling in the pathophysiology of aortopathies such as ARCL 1B has led to targeted medical therapies. Specific surgical techniques can lead to optimal outcomes in these patients.

"PINOT": time-resolved parallel magnetic resonance imaging with a reduced dynamic field of view.

This article introduces a novel method named "Parallel Imaging and Noquist in Tandem" (PINOT) for accelerated image acquisition of cine cardiac magnetic resonance imaging. This method combines two prior information formalisms, the SPACE-RIP implementation of parallel imaging and the Noquist method for reduced-data image reconstruction with prior knowledge of static and dynamic regions in the field of view. The general theory is presented, and supported by results from experiments using time-resolved two-dimensional simulation data and retrospectively sub-sampled magnetic resonance imaging data with acceleration factors around 4. A signal-to-noise ratio analysis and a comparison study with TSENSE and k-t SENSE show that PINOT performs favorably in preserving edge detail, at a cost in signal-to-noise ratio and computational complexity.

Hemodynamic predictors of aortic dilatation in bicuspid aortic valve by velocity-encoded cardiovascular magnetic resonance.

BACKGROUND: Congenital bicuspid aortic valve (BAV) is a significant risk factor for serious complications including valve dysfunction, aortic dilatation, dissection, and sudden death. Clinical tools for identification and monitoring of BAV patients at high risk for development of aortic dilatation, an early complication, are not available. METHODS: This paper reports an investigation in 18 pediatric BAV patients and 10 normal controls of links between abnormal blood flow patterns in the ascending aorta and aortic dilatation using velocity-encoded cardiovascular magnetic resonance. Blood flow patterns were quantitatively expressed in the angle between systolic left ventricular outflow and the aortic root channel axis, and also correlated with known biochemical markers of vessel wall disease. RESULTS: The data confirm larger ascending aortas in BAV patients than in controls, and show more angled LV outflow in BAV (17.54 +/- 0.87 degrees) than controls (10.01 +/- 1.29) (p = 0.01). Significant correlation of systolic LV outflow jet angles with dilatation was found at different levels of the aorta in BAV patients STJ: r = 0.386 (N = 18, p = 0.048), AAO: r = 0.536 (N = 18, p = 0.022), and stronger correlation was found with patients and controls combined into one population: SOV: r = 0.405 (N = 28, p = 0.033), STJ: r = 0.562 (N = 28, p = 0.002), and AAO r = 0.645 (N = 28, p < 0.001). Dilatation and the flow jet angle were also found to correlate with plasma levels of matrix metallo-proteinase 2. CONCLUSIONS: The results of this study provide new insights into the pathophysiological processes underlying aortic dilatation in BAV patients. These results show a possible path towards the development of clinical risk stratification protocols in order to reduce morbidity and mortality for this common congenital heart defect.

Rerouting of Cerebral Circulation: Extensive Transcatheter Aortic Arch Revision.

We describe an adolescent with long-standing atresia of the head/neck arteries and severe aortic coarctation. Because of progressive symptoms, a series of interventions was undertaken to provide direct aorta-to-carotid artery flow and coarctation treatment. This case highlights the unusual physiological features associated with atresia of all head and neck arteries. (Level of Difficulty: Advanced.).

Double Aortic Arch With Previously Undescribed Head and Neck Vessel Branching.

Vascular ring in the form of a double aortic arch is a rare anomaly that can cause airway compression. It occasionally occurs with unusual head and neck vessel branching. A 5-year-old boy with chronic respiratory symptoms was referred because of a tracheal indentation on his chest x-ray. Magnetic resonance imaging showed a double aortic arch with arch origins of a common carotid, vertebral, and subclavian on the right and internal and external carotids, vertebral, and subclavian arteries on the left. Our case represents, to our knowledge, the first report of a double aortic arch with 7 separate vessels arising from the transverse arches.

Systolic ejection click versus split first heart sound: Are our ears deceiving us?

OBJECTIVE: Bicuspid aortic valve (BAV) disease is associated with potential lifetime complications, but auscultation of a BAV click is commonly missed or mistaken for a benign split first heart sound. Our objective was to determine whether pediatric cardiologists could reliably distinguish between BAV clicks and benign split first heart sounds. DESIGN: Quality evaluation project using de-identified recordings from an outpatient pediatric cardiology clinic. OUTCOME MEASURES: Twenty-one cardiologists listened to five de-identified recordings of pediatric heart sounds (three with BAV clicks, two with mitral components of benign split first heart sounds) and indicated whether they believed each recording was a BAV or split first heart sound. The accuracy of diagnoses was determined using percent agreement and calculated kappa coefficients for the cohort and subgroups based on those with less than 10 years of experience versus those with ≥10 years. To assess precision, a kappa extension was used for multiple raters to assess interrater agreement. RESULTS: Among participants, diagnostic accuracy of BAV click was 38%, while accuracy of split first heart sound was 41%. No participant correctly diagnosed all sounds. No difference in agreement was observed when stratifying by experience. Kappa was -0.11 (CI 95% -0.31 to 0.08) for all raters, -0.03 (CI 95% -0.39 to 0.33) for those with less than 10 years' experience, and -0.15 (CI 95% -0.38 to 0.08) for those with ≥10 years' experience. The kappa statistic among the 21 raters was 0.01 (95% CI -0.03 to 0.04), indicating poor precision among the raters. CONCLUSIONS: In this sample of pediatric cardiologists, the diagnostic accuracy of BAV clicks versus split first heart sounds was worse than chance. There was no association between years of experience and diagnostic accuracy. While further study is needed, these data suggest that an echocardiogram may be valuable when either a systolic ejection click or split first heart sound is heard.

Tricuspid regurgitation in patients with repaired Tetralogy of Fallot and its relation to right ventricular dilatation.

In a cohort of 56 school-aged children with repaired tetralogy of Fallot, significant (moderate to severe) tricuspid regurgitation was common (32% of patients) and was related to both tricuspid annulus dilatation and structural valve abnormalities that were potentially related to previous surgery. Even after adjusting for pulmonary regurgitation, tricuspid regurgitation was significantly correlated with right ventricular volume (r= 0.39, p = 0.009), suggesting that tricuspid regurgitation as well as pulmonary regurgitation may contribute significantly to progressive right ventricular dilatation in this population.

Association between cardiac tumors and tuberous sclerosis in the fetus and neonate.

A retrospective review was performed in 94 patients with > or =1 cardiac tumors seen on prenatal or neonatal echocardiography at 5 major referral centers. Tuberous sclerosis was present in 68 patients diagnosed with a cardiac tumor in utero or during the neonatal period, including 61 of 64 with multiple tumors.

Arrhythmia phenotype during fetal life suggests long-QT syndrome genotype: risk stratification of perinatal long-QT syndrome.

BACKGROUND: Fetal arrhythmias characteristic of long QT syndrome (LQTS) include torsades de pointes (TdP) and/or 2° atrioventricular block, but sinus bradycardia, defined as fetal heart rate<3% for gestational age, is most common. We hypothesized that prenatal rhythm phenotype might predict LQTS genotype and facilitate improved risk stratification and management. METHOD AND RESULTS: Records of subjects exhibiting fetal LQTS arrhythmias were reviewed. Fetal echocardiograms, neonatal ECG, and genetic testing were evaluated. We studied 43 subjects exhibiting fetal LQTS arrhythmias: TdP±2° atrioventricular block (group 1, n=7), isolated 2° atrioventricular block (group 2, n=4), and sinus bradycardia (group 3, n=32). Mutations in known LQTS genes were found in 95% of subjects tested. SCN5A mutations occurred in 71% of group 1, whereas 91% of subjects with KCNQ1 mutations were in group 3. Small numbers of subjects with KCNH2 mutations (n=4) were scattered in all 3 groups. Age at presentation did not differ among groups, and most subjects (n=42) were live-born with gestational ages of 37.5±2.8 weeks (mean±SD). However, those with TdP were typically delivered earlier. Prenatal treatment in group 1 terminated (n=2) or improved (n=4) TdP. The neonatal heart rate-corrected QT interval (mean±SE) of group 1 (664.7±24.9) was longer than neonatal heart rate-corrected QT interval in both group 2 (491.2±27.6; P=0.004) and group 3 (483.1±13.7; P<0.001). Despite medical and pacemaker therapy, postnatal cardiac arrest (n=4) or sudden death (n=1) was common among subjects with fetal/neonatal TdP. CONCLUSIONS: Rhythm phenotypes of fetal LQTS have genotype-suggestive features that, along with heart rate-corrected QT interval duration, may risk stratify perinatal management.

Detection of a coronary artery anomaly after a sudden cardiac arrest in a 17 Year-old with D-transposition of the great arteries status post arterial switch operation: a case report.

Long-term follow-up and testing for patients who have undergone congenital heart surgery is an evolving field. We report the case of a 17-year-old patient who had an arterial switch operation as an infant for d-transposition of the great vessels and suffered sudden cardiac arrest while participating in a cross-country event. Previous evaluations, including a cardiac catheterization and stress testing, did not indicate any identifiable abnormalities. After the arrest, a computed tomography angiogram of his chest showed an abnormal takeoff of the reimplanted left coronary artery.

Pulmonary valve replacement after tetralogy of Fallot repair in preadolescent patients.

BACKGROUND: After tetralogy of Fallot (TOF) repair, severe pulmonary insufficiency is known to impair biventricular function. Pulmonary valve replacement (PVR) alleviates symptoms, normalizes right ventricular volumes, and improves ventricular function. Most studies addressing the role of PVR have examined older adolescents or adults. Less is known about the potential benefits of PVR in preadolescents with TOF and significant right ventricular dilatation. METHODS: We reviewed the clinical data for all preadolescents (< or = 13 years) with TOF who underwent cardiac magnetic resonance imaging (cMRI) or PVR, or both. Serial cMRI data were analyzed to determine the change in indexed right ventricular end-diastolic volume (RVEDV) and biventricular ventricular ejection fractions. Available cMRI data after PVR were compared with data before PVR. RESULTS: During the study period, 101 preadolescents with TOF had cMRI. The median age of complete repair was 6 months (range, 6 days to 3.4 years). The mean RVEDV at the first study was 135 +/- 39 mL/m(2). For 32 with serial cMRI studies, the RVEDV increased at a mean yearly rate of 9 mL/m(2). Ventricular systolic function was impaired in 46 (46%). Forty-two patients underwent PVR at a mean age of 8 +/- 3 years. No hospital deaths occurred, and no pulmonary valve reinterventions have been required. CONCLUSIONS: Significant right ventricular dilatation is common in preadolescents after transannular patch repair of TOF. Routine follow-up of this population should incorporate cMRI. Further studies will be needed to determine whether a strategy of early PVR might improve intermediate-term outcome.

Real-time three-dimensional echocardiographic acquisition and quantification of left ventricular indices in children and young adults with congenital heart disease: comparison with magnetic resonance imaging.

BACKGROUND: Echocardiographic assessment of left ventricular (LV) contractility and dimensions is important in the management of patients with congenital heart disease. Conventional two-dimensional measures are limited because of volume or pressure-overloaded right ventricles that may distort the septal planes. Real-time three-dimensional echocardiography (RT3DE) has overcome these limitations; however, postprocessing image reconstruction and analysis are required. We compared LV indices calculated by new online RT3DE software with those obtained by magnetic resonance imaging (MRI) in patients with congenital heart disease. METHODS: Twelve patients (ages 1-33 years, median age = 15.9 years) with congenital heart disease underwent RT3DE and cardiac MRI. End-diastolic and end-systolic LV volumes, stroke volume, ejection fraction, and mass were calculated online using biplane method-of-discs and semiautomated border detection echocardiographic techniques. RESULTS: All RT3DE volumes correlated strongly with MRI (r = 0.93-0.99, P < .001). Ejection fraction had a lower correlation (r = 0.69, P = .013). There was no significant underestimation or overestimation of MRI values by RT3DE. Both biplane method-of-discs and semiautomated border detection echocardiographic techniques had excellent volume correlation (r = 0.94-0.99, P < .001). Interobserver variability was 7%. CONCLUSIONS: Combined RT3DE acquisition and analysis machines can accurately assess the LV in patients with congenital heart disease, thus impacting clinical management and perhaps obviating the need for MRI in some cases.

Fas ligand gene transfer to the embryonic heart induces programmed cell death and outflow tract defects.

The remodeling of the embryonic avian cardiac outflow tract (OFT) involves the removal of cardiomyocytes by programmed cell death (PCD). In contrast, the prevalence of PCD is low in the atrial or ventricular myocytes during this period of development. To determine if this selective PCD is due to the unique ability of the OFT cardiomyocytes to execute PCD, we transduced the embryonic chicken heart in ovo with recombinant adenovirus expressing a death (FasL) ligand. This resulted in programmed cell death in atrial, ventricular, and OFT cardiomyocytes as evidenced by chromosomal fragmentation, accumulation of lysosomes, and Caspase enzymatic activity. Consistent with the widespread induction of PCD, transcripts for the Fas receptor were detected in all chambers of the heart throughout development. The precocious and widespread activation of PCD in the OFT myocardium resulted in a marked dimunition of the subpulmonic myocardial infundibulum, and transposition of the aorta side-by-side with the pulmonary artery and connecting to the right ventricle. Defects in other cardiac structures are also described. We conclude that the regulated removal of OFT cardiomyocytes by PCD is required for the great vessels to make their proper connections with the ventricles in the transition to a dual circulation. The malalignment of the great vessels described in this animal model are similar to those described in congenital human conotruncal heart defects, suggesting that PCD-dependent remodeling of the OFT myocardium could be a target of genetic mutations or teratogens that cause human conotruncal heart defects.