Sujatha Buddhe

Common arterial trunk (CAT), or truncus arteriosus, is a rare form of cyanotic congenital heart disease and is highly associated with DiGeorge syndrome (microdeletion 22q11.2). Prenatal diagnosis is highly feasible, allowing proper delivery planning and postnatal management. The clinical presentation is highly variable depending on the anatomical variation; however, most commonly presenting with mild cyanosis and significant tachypnea, although these patients can often go undetected in the immediate newborn period. Transthoracic echocardiography is adequate for diagnosis and detailed anatomical delineation in the majority. Additional imaging modalities such as cardiac catheterization, computed tomography angiography, or cardiac magnetic resonance imaging can be helpful in those with more complex pulmonary artery (PA) or aortic anatomy, or in the older repaired. The surgical management of CAT is complete repair in the neonatal period with resection of branch PAs from the CAT with placement of a right ventricular (RV)-to-PA conduit and patch closure of the ventricular septal defect. Overall surgical outcomes are excellent in most centers, with the expectation that the child will eventually outgrow the RV-to-PA conduit and require reoperation. Other potential reoperations or postsurgical interventions in addition to the RV-to-PA conduit may involve the truncal valve or branch PAs.

Background In CHD, three-dimensional strain analysis may overcome limitations of Doppler and two-dimensional strain of the left ventricle. The aims of this study were to evaluate feasibility and reproducibility of three-dimensional longitudinal, circumferential, and radial systolic strain by three-dimensional speckle-tracking echocardiography compared with two-dimensional echocardiography. Methods Patients with CHD, biventricular circulation with a systemic left ventricle, and who had two- and three-dimensional imaging performed on the same day from 2010 to 2014 were included. Quantitative two- and three-dimensional strain analyses were performed (two-dimensional cardiac performance analysis version 1.2 and four-dimensional left ventricular analysis version 3.1). Intra- and inter-observer variabilities were calculated on 25 studies. Results A total of 30 patients, including 19 (61%) males, with a median age of 3.6 years (0.1–22 years) were included. The mean fractional shortening was 34.6±5.3%, and the mean ejection fraction was 62.0±6.4%. Measurement of two- and three-dimensional strain was feasible in >95% of segments. Good correlation was observed between longitudinal and circumferential strain (r=0.92, p⩽0.001 and r=0.87, p⩽0.001), but not radial strain (r=0.29, p=0.2). Intra- and inter-observer agreements were better for three-dimensional compared with two-dimensional strain, and better for both two- and three-dimensional longitudinal and circumferential strains compared with radial strain. Conclusion Left ventricular three-dimensional strain analysis is feasible in children with CHD. The reproducibility of longitudinal and circumferential strain by three-dimensional analyses is better. Further longitudinal studies are warranted for the potential clinical application of this new technology.

Background: Echocardiogram has limitations in effectively assessing right ventricular (RV) function in children post tetralogy of Fallot (TOF) repair. We evaluated the utility of speckle tracking echocardiography (STE)‐based RV global longitudinal strain (GLS) for the assessment of RV systolic function.Methods: All patients with repaired TOF who had both echocardiograms and cardiac MRI (CMR) within a 6‐month interval were included. RV volumes and ejection fraction (EF) were obtained by CMRs. Traditional echocardiographic function parameters and RV GLS were compared to CMR‐derived RV EF. Subjects were divided into two groups based on CMR RV EF (group I: RV EF ≥45%; and group II: RV EF P<.001). By ROC analysis, an RV GLS cutoff value of −18% had 78% sensitivity and 77% specificity in identifying RV EF P<.001). Intra‐ and inter‐observer reproducibility of RV GLS were good.Conclusion: RV GLS is a simple and effective tool for the assessment of RV systolic function in patients post TOF repair. This technique would help further refine patient selection for timing of CMR and management.

Cardiomyopathy in Duchenne muscular dystrophy (DMD) is associated with death in approximately 40% of patients. Echocardiography is routinely used to assess left ventricular (LV) function; however, it has limitations in these patients. We compared echocardiographic measures of cardiac function assessment to cardiac MRI. We included children and young adults with DMD who had MRI performed between January 2010 and July 2015. We measured echocardiographic and MRI parameters of function assessment, including strain. Presence of late gadolinium enhancement (LGE) was assessed by MRI. Subjects were divided into two groups based on MRI left ventricular ejection fraction (LVEF): group I, LVEF ≥55% and group II, LVEF <55%. We included 41 studies in 33 subjects, with 25 in group I and 16 in group II. Mean age of subjects was 13.6 ± 2.8 years and mean duration between echocardiogram and MRI was 7.6 ± 4.1 months. Only 8 of 16 (50%) patients in group II had diminished function on echocardiogram. Echocardiographic images were suboptimal in 16 subjects (39%). Overall, echocardiographic parameters had weak correlation with MRI-derived ejection fraction percentage. MRI-derived myocardial strain assessment has better correlation with MRI ejection fraction as compared to echocardiography-derived strain parameters. Echocardiography-based ventricular functional assessment has weak correlation with MRI parameters in children and young adults with Duchenne muscular dystrophy. While this correlation improves in the subset of subjects with adequate echocardiographic image quality, it remains modest and potentially suboptimal for clinical management. Accordingly, we conclude that MRI should be performed routinely and early in children with DMD, not only for LGE imaging but also for functional assessment.

Heart transplant recipients are at risk for developing left ventricular (LV) dysfunction. While traditional echocardiographic parameters have limitations, speckle tracking echocardiography (STE) is a novel technique shown to be more sensitive and accurate in adult studies for evaluating ventricular systolic and diastolic function. Pediatric heart transplant recipients undergoing routine cardiac catheterization were included. Ratio of mitral early diastolic velocity-to-strain rate during early LV filling (E/SR(E)) and global longitudinal peak systolic strain (GLPSS) was measured by STE imaging. These were compared with wedge pressures by catheterization and traditional echocardiographic parameters. A total of 50 subjects (46% males) were included. Mean age of the subjects was 13.0 ± 6.3 years and time since transplant was 4.1 years (range 0.2-17.1 years). While peak mitral inflow to late diastolic velocity (E/A ratio) was the only traditional diastolic function parameter having significant correlation with pulmonary capillary wedge pressure (PCWP) (r = 0.3; P = .3), STE-derived E/SR(E) had modest correlation with PCWP (r = 0.55; P < .01). Also, while most traditional systolic function parameters were normal, 12 subjects (24%) had GLPSS > -18%. Interestingly, subjects with coronary artery disease (n = 6) had significantly higher E/SR(E) (71.9 ± 28.4) compared to subjects without (45.2 ± 10.8; P < .001). Diastolic function parameters by STE imaging correlate better with gold standard PCWP measurement than traditional echocardiographic parameters. Also, utilizing STE, abnormalities of longitudinal LV systolic function may be more common than previously thought in pediatric heart transplant recipients without acute graft rejection, despite "normal" systolic function by traditional echocardiogram.