Longitudinal Deformation of the Right Ventricle in Hypoplastic Left Heart Syndrome: A Comparative Study of 2D-Feature Tracking Magnetic Resonance Imaging and 2D-Speckle Tracking Echocardiography.

In hypoplastic left heart syndrome (HLHS), long-term outcome is closely related to right ventricular function. Echocardiography and magnetic resonance imaging (MRI) are routinely used for functional assessment. MRI 2D-tissue feature tracking (2D-FT) allows quantification of myocardial deformation but has not yet been applied to HLHS patients. We sought to investigate the feasibility of this technique and to compare the results to 2D-speckle tracking echocardiography (2D-STE). In routine MRI 2D anatomical four chamber view, cine images were recorded in 55 HLHS patients (median age 4.9 years [1.6, 17.0]). Regional and global peak systolic longitudinal strain (LS) and strain rate (LSR) were determined using 2D-FT software. Echocardiographic four chamber view was analyzed with 2D-STE. Visualization of all myocardial segments with MRI was excellent, regional, and global LS and LSR could be assessed in all data sets. In 2D-STE, 28% of apical segments could not be analyzed due to poor image quality. Agreement of 2D-FT MRI and 2D-STE was acceptable for global LS, but poor for global LSR. In MRI, regional LS was lower in the septal segments, while LSR was not different between the segments. GLS and GLSR correlated with ejection fraction (GLS: r = - 0.45 and r < 0.001, GLSR: r = - 0.34 and p = 0.01). With new post-processing options, the assessment of regional and global LS and LSR is feasible in routine MRI of HLHS patients. For LS, results were comparable with 2D-STE. The agreement was poor for LSR, which might relate to differences in temporal resolution between the two imaging modalities.

How Could Aortic Atresia With Interrupted Aortic Arch Survive? About a Neonatal Repair on Two Ventricles.

Aortic atresia with interrupted aortic arch (IAA) is an exceptional condition. In absence of associated lesion, the flow to the brain and the retrograde flow to the coronary arteries can only come from vessels on the descending aorta. This flow needs to be large enough to supply the brain and the myocardium. The only IAA type compatible with survival is type C where the flow from descending aorta could be insured by the left carotid and the left vertebral artery, branch of the left subclavian artery. Only one such a case was described in the literature. All the other surviving cases had an associated lesion including: a double aortic arch, an aorto-pulmonary window (AP window), an aberrant right subclavian artery or a bilateral patent ductus arteriosus (PDA). We report a case of aortic atresia with IAA type B associated with a double aortic arch that underwent a successful bi-ventricular one-stage neonatal Norwood-Rastelli repair and is doing well after 18 months.

Improved Lung Perfusion After Left Pulmonary Artery Patch Enlargement During the Norwood Operation.

BACKGROUND: Optimal pulmonary perfusion is crucial for a well-functioning Fontan circulation in patients with hypoplastic left heart syndrome (HLHS). To obtain an adequate size of the left pulmonary artery (LPA), patch enlargement is a routine part of the hemi-Fontan procedure in our center. However, LPA patch enlargement at the time of the modified Norwood procedure may have surgical advantages. Therefore, the aim of this study was to evaluate whether anatomic and functional effects of the new approach are superior. METHODS: A total of 51 consecutive HLHS patients underwent a cardiovascular magnetic resonance imaging study including assessment of LPA anatomy and lung perfusion. The LPA of 20 patients was enlarged during the modified Norwood procedure (group N) and of 31 patients during the hemi-Fontan procedure (group HF). RESULTS: The median indexed cross-sectional area of the LPA in group N was significantly higher than in group HF (49.5 versus 27.9 mm2/m2, p < 0.0001). The regional pulmonary perfusion as measured by first-pass, contrast-enhanced signal intensity upslope was significantly improved in group N (left side 0.67 s-1 versus 0.40 s-1, p = 0.002; right side 0.84 s-1 versus 0.52 s-1, p = 0.01). The total hemi-Fontan bypass and procedure times were significantly shorter in group N (both p < 0.001). CONCLUSIONS: These first magnetic resonance imaging data show that HLHS patients after LPA patch enlargement during the modified Norwood procedure have significantly higher LPA cross-sectional areas and show improved lung perfusion and shorter overall procedure time as compared with LPA patching during second stage (hemi-Fontan). Therefore, this promising surgical technique may improve blood flow dynamics of the Fontan circulation in the long run.

Restrictive enlargement of the pulmonary annulus at repair of tetralogy of Fallot: a comparative 10-year follow-up study.

OBJECTIVES: Since 1996, our centre performs restrictive enlargement of the pulmonary annulus at surgical repair of tetralogy of Fallot. A transannular patch is only used if the z-score of the pulmonary annulus is smaller than -2. We sought to determine whether this strategy reduces pulmonary insufficiency (PI) and reoperation rate compared to a nationwide contemporary cohort that has not been operated using a uniform strategy. METHODS: Eighty-seven tetralogy of Fallot patients were included in the study (Group 1). One hundred sixty-seven tetralogy of Fallot patients from the Competence Network for Congenital Heart Disease served as controls (Group 2). Clinical, echocardiographic, electrocardiogram, cardiovascular magnetic resonance and outcome data were analysed. RESULTS: Follow-up time since repair was not different between groups [12.9 (7.8-18.8) vs 13.1 (5.2-16.9) years, P = 0.96] while transannular patch rate was significantly lower in Group 1 (32.2% vs 64.7%, P < 0.001). Ten-year freedom from reoperation for PI was significantly higher in our cohort (98% vs 92%, P = 0.01). Multivariable analysis identified restrictive enlargement as the only predictor for no need of reoperation [hazard ratio 0.4 (95% confidence interval 0.24-0.84), P < 0.01]. In Group 1, cardiovascular magnetic resonance-derived volumes were smaller (indexed end-diastolic volume: 103 ± 24 vs 123 ± 31 ml/m2, P < 0.001; indexed end-systolic volume: 53 ± 19 vs 59 ± 20 ml/m2, P = 0.04) and regurgitation fraction was lower (21 ± 14 vs 31 ± 17%, P < 0.001). CONCLUSIONS: Restrictive enlargement of the pulmonary annulus reduces PI and limits the amount of right ventricular dilatation at intermediate-term follow-up. The need for reoperation to alleviate PI is significantly lower compared to a contemporary cohort. Restrictive enlargement strategy has a stronger influence on freedom from reoperation than the use of a transannular patch. CLINICAL TRIAL REGISTRATION: WHO Main ID: DRKS00010087. URL: http://apps.who.int/trialsearch/Trial2.aspx?TrialID=DRKS00010087.

Prevalence of and Reasons for Patients Leaving Against Medical Advice from Paediatric Wards in Oman.

The objective of this study was to determine the prevalence of and reasons for patients leaving against medical advice (LAMA) in a paediatric setting in Oman. This retrospective study was carried out between January 2007 and December 2009 and assessed patients who left the paediatric wards at the Royal Hospital, Muscat, Oman, against medical advice. Of 11,482 regular discharges, there were 183 cases of LAMA (prevalence: 1.6%). Dissatisfaction with treatment and a desire to seek a second opinion were collectively the most cited reasons for LAMA according to data from the hospital's electronic system (27.9%) and telephone conversations with patients' parents (55.0%). No reasons for LAMA were documented in the hospital's electronic system for 109 patients (59.6%). The low observed prevalence of LAMA suggests good medical practice at the Royal Hospital. This study indicates the need for thorough documentation of all LAMA cases to ensure the availability of high-quality data for healthcare workers involved in preventing LAMA.

Frequent Dilatation of the Descending Aorta in Children With Hypoplastic Left Heart Syndrome Relates to Decreased Aortic Arch Elasticity.

BACKGROUND: Patients with hypoplastic left heart syndrome after a Norwood operation show dilatation and reduced distensibility of the reconstructed proximal aorta. Cardiac magnetic resonance imaging (CMR) and angiographic examinations indicate that the native descending aorta (DAo) is also dilated, but this has not been studied in detail. METHODS AND RESULTS: Seventy-nine children with hypoplastic left heart syndrome in Fontan circulation (aged 6.3±3.2 years) and 18 control participants (aged 6.8±2.4 years) underwent 3.0-tesla CMR. Gradient-echo cine and phase-contrast imaging was applied to measure cross-sectional areas (CSAs), distensibility, pulse wave velocity, and the incremental elastic modulus of the thoracic aorta. CSA of the DAo in patients was also compared with published percentiles for aortic CSA. Patients had significantly larger CSA of the DAo at the level of pulmonary artery bifurcation (229.1±97.2 versus 175.7±24.3 mm/m(2), P=0.04) and the diaphragm (196.2±66.0 versus 142.6±16.7 mm/m(2), P<0.01). In 41 patients (52%), CSA of the DAo was >95th percentile level for control participants, and the incremental elastic modulus of the aortic arch and the DAo was higher than in patients with normal CSAs (arch: 90.1±64.3 versus 45.6±38.9 m/s; DAo: 86.3±53.7 versus 47.1±47.6 m/s; P<0.01). Incremental elastic modulus of the aortic arch and the DAo correlated with the CSA of the DAo (arch: r=0.5; DAo: r=0.49; P<0.01). CONCLUSIONS: Children with hypoplastic left heart syndrome frequently show dilatation of their DAo associated with increased stiffness of the aortic arch. Higher aortic impedance increases the afterload of the systemic circulation and likely contributes to the burden of the systemic right ventricle.