Biventricular Conversion of Borderline Hypoplastic Left Heart Complex Facilitated by Spontaneous Closure of the Atrial Septum.

We present the case of a child with borderline hypoplastic left heart complex who initially received Norwood and Glenn operations without atrial septectomy and was later converted to a biventricular circulation after progressive growth of the left ventricle as assessed by serial echocardiography and cardiac magnetic resonance imaging.

Improving maternal-infant bonding after prenatal diagnosis of CHD.

BACKGROUND: Infants with prenatally diagnosed CHD are at high risk for adverse outcomes owing to multiple physiologic and psychosocial factors. Lack of immediate physical postnatal contact because of rapid initiation of medical therapy impairs maternal-infant bonding. On the basis of expected physiology, maternal-infant bonding may be safe for select cardiac diagnoses. METHODS: This is a single-centre study to assess safety of maternal-infant bonding in prenatal CHD. RESULTS: In total, 157 fetuses with prenatally diagnosed CHD were reviewed. On the basis of cardiac diagnosis, 91 fetuses (58%) were prenatally approved for bonding and successfully bonded, 38 fetuses (24%) were prenatally approved but deemed not suitable for bonding at delivery, and 28 (18%) were not prenatally approved to bond. There were no complications attributable to bonding. Those who successfully bonded were larger in weight (3.26 versus 2.6 kg, p<0.001) and at later gestation (39 versus 38 weeks, p<0.001). Those unsuccessful at bonding were more likely to have been delivered via Caesarean section (74 versus 49%, p=0.011) and have additional non-cardiac diagnoses (53 versus 29%, p=0.014). There was no significant difference regarding the need for cardiac intervention before hospital discharge. Infants who bonded had shorter hospital (7 versus 26 days, p=0.02) and ICU lengths of stay (5 versus 23 days, p=0.002) and higher survival (98 versus 76%, p<0.001). CONCLUSION: Fetal echocardiography combined with a structured bonding programme can permit mothers and infants with select types of CHD to successfully bond before ICU admission and intervention.

PRKAG2 mutations presenting in infancy.

PRKAG2 encodes the γ2 subunit of AMP-activated protein kinase (AMPK), which is an important regulator of cardiac metabolism. Mutations in PRKAG2 cause a cardiac syndrome comprising ventricular hypertrophy, pre-excitation, and progressive conduction-system disease, which is typically not diagnosed until adolescence or young adulthood. However, significant variability exists in the presentation and outcomes of patients with PRKAG2 mutations, with presentation in infancy being underrecognized. The diagnosis of PRKAG2 can be challenging in infants, and we describe our experience with three patients who were initially suspected to have Pompe disease yet ultimately diagnosed with mutations in PRKAG2. A disease-causing PRKAG2 mutation was identified in each case, with a novel missense mutation described in one patient. We highlight the potential for patients with PRKAG2 mutations to mimic Pompe disease in infancy and the need for confirmatory testing when diagnosing Pompe disease.

Associations Between Day of Admission and Day of Surgery on Outcome and Resource Utilization in Infants With Hypoplastic Left Heart Syndrome Who Underwent Stage I Palliation (from the Single Ventricle Reconstruction Trial).

Newborns with hypoplastic left heart syndrome and other single right ventricular variants require substantial health care resources. Weekend acute care has been associated with worse outcomes and increased resource use in other populations but has not been studied in patients with single ventricle. Subjects of the Single Ventricle Reconstruction trial were classified by whether they had a weekend admission and by day of the week of Norwood procedure. The primary outcome was hospital length of stay (LOS); secondary outcomes included transplant-free survival, intensive care unit (ICU) LOS, and days of mechanical ventilation. The Student's t test with log transformation and the Wilcoxon rank-sum test were used to analyze associations. Admission day was categorized for 533 of 549 subjects (13% weekend). The day of the Norwood was Thursday/Friday in 39%. There was no difference in median hospital LOS, transplant-free survival, ICU LOS, or days ventilated for weekend versus non-weekend admissions. Day of the Norwood procedure was not associated with a difference in hospital LOS, transplant-free survival, ICU LOS, or days ventilated. Prenatally diagnosed infants born on the weekend had lower mean birth weight, younger gestational age, and were more likely to be intubated but did not have a difference in measured outcomes. In conclusion, in this cohort of patients with single right ventricle, neither weekend admission nor end-of-the-week Norwood procedure was associated with increased use of hospital resources or poorer outcomes. We speculate that the complex postoperative course following the Norwood procedure outweighs any impact that day of admission or operation may have on these outcomes.

Right ventricular echocardiographic indices predict poor outcomes in infants with persistent pulmonary hypertension of the newborn.

AIMS: Infants with persistent pulmonary hypertension of the newborn (PPHN) have elevated pulmonary vascular resistance that can lead to right ventricular (RV) failure and death. Clinicians must decide which infants will fail conventional therapy and require transfer to extra corporeal membrane oxygenation (ECMO) centres, but accurate echocardiographic predictors have not been identified. We assessed echocardiographic measurements of RV pressure and function in predicting progression to death or ECMO in infants with PPHN. METHODS AND RESULTS: Echocardiograms for infants ≥35-week gestation with a clinical diagnosis of PPHN were retrospectively reviewed. Traditional and strain echocardiographic measures were compared for those with or without the primary outcome of ECMO/cardiovascular death. Receiver operator curves identified cut points for measures that were significantly different. Of the 86 subjects analysed, 25 (29%) of the patients had the primary outcome of ECMO/death. The ECMO/death group had diminished tricuspid annular plane systolic excursion (TAPSE; P = 0.002) and RV global longitudinal peak strain (GLPS; P = 0.03), a predominant right-to-left shunt across the patent ductus arteriosus (PDA; P = 0.05), and an elevated oxygenation index (OI; P < 0.001). Sensitivity/specificity for TAPSE <4 mm was 56 and 85%, and for GLPS greater than or equal to -9% was 52 and 77%. CONCLUSION: TAPSE, GLPS, and right-to-left PDA shunting were associated with progression to death/ECMO. RV free wall strain was not associated with the outcome, suggesting that diminished global strain better reflects clinical outcomes in this group. These thresholds may assist in the decision-making to transfer high-risk infants to ECMO centres.

Left ventricular myocardial performance index change for detection of acute cellular rejection in pediatric heart transplantation.

EMB, the gold standard for diagnosis of ACR, poses unique risks in children. Limited cross-sectional data have associated LV MPI with ACR. We hypothesize that a relative change in MPI from baseline without ACR to the time of ACR will better detect ACR than an absolute threshold LV MPI value. We identified 40 children with ACR ≥60 days post-transplant matching them by age and time from transplantation to 40 children without ACR. There was a significant increase in LV MPI at time of ACR vs. baseline (0.59 ± 0.17 vs. 0.41 ± 0.11; p < 0.001). There was no difference in LV MPI between baseline and follow-up (0.41 ± 0.11 vs. 0.42 ± 0.11; p = 0.65). An absolute increase in LV MPI of ≥0.47 had 82.5% sensitivity and 85% specificity for ACR, whereas an increase in LV MPI from baseline of ≥20.4% was 90% sensitive and 100% specific. Serial measurement of LV MPI appears to be a sensitive and specific marker of ACR. LV MPI shows good interobserver agreement and increases at the time of EMB-proven ACR with subsequent resolution to baseline measurements upon EMB-proven resolution of ACR. Future studies in larger, prospective cohorts should be undertaken to validate these findings.

Prognostic significance of recurrent grade 1B rejection in the first year after pediatric cardiac transplantation: a case for reinstatement of the 1B rejection grade.

The 2005 ISHLT rejection grading system merged grades 1A, 1B, and 2 into a single grade (1R) assuming equivalent prognostic significance. We hypothesized that recurrent 1B ACR is associated with adverse outcomes. Data on all heart transplant recipients at our center from 1990 to 2007 were reviewed. Patients were excluded if they had more than one grade ≥ 3A/2R biopsy in the first six wk or any grade ≥ 3A/2R biopsies during the first year thereafter. Patients with ≥ 2 grade 1B biopsies from six wk to one yr were classified as "recurrent 1B." Outcomes were freedom from late (greater than one yr) ACR (grade ≥ 3A/2R), CAD, retransplantation/death, and a composite end-point. Sixty-two patients (53 non-recurrent 1B, nine recurrent 1B) met inclusion criteria. In univariate analyses, recurrent 1B status was associated with decreased freedom from late ACR (p < 0.001), CAD (p = 0.004), and the composite outcome (p < 0.001). There was no difference in freedom from retransplantation/death (p = 0.48). After controlling for demographic differences between the groups, recurrent 1B status was independently associated with late ACR (HR 5.90; p = 0.002) and the composite outcome (HR 4.52; p = 0.002). These data suggest that further study of the impact of removal of the 1B classification from the ISHLT grading scheme is warranted.

Effect of dexmedetomidine on pulmonary artery pressure after congenital cardiac surgery: A pilot study.

OBJECTIVE: To characterize the effects of dexmedetomidine on the pulmonary artery pressure in patients after congenital cardiac surgery. DESIGN: Prospective observational pilot study. SETTING: Pediatric cardiac intensive care unit at a university hospital. PATIENTS: Twenty-two patients who received dexmedetomidine after cardiothoracic surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: An echocardiogram was performed at three time points: 1) baseline (T0); 2) 6 mins after dexmedetomidine loading (T1); and 3) 1 hr after initiation of dexmedetomidine infusion (T2). Transthoracic echocardiography was used to estimate pulmonary artery pressure based on tricuspid regurgitant velocity (4 x Velocity2) plus central venous pressure. Twenty-two patients aged 0.9 yrs old (interquartile range, 7.9) were enrolled at a median of 1 hr (1.5) after surgery. Dexmedetomidine loading, 0.62 microg/kg (0.5), was given in all patients followed by 0.5 microg/kg/hr (0.6) at T1 and 0.65 microg/kg/hr (0.5) at T2. None of the patients had any increase in pulmonary artery pressure. Overall, the pulmonary artery pressure decreased from 30 mm Hg (13) at T0 to 24 mm Hg (10) at T1 and 26 mm Hg (8) at T2 (p < .001). The pulmonary artery pressure/systemic systolic blood pressure ratio decreased from 33% (12) at T0 to 23% (15) at T1 and 25% (13) at T2 (p = .002). There was no difference in the left ventricular function, Fio2, oxygen %, Po2, CO2, and vasoactive agents. CONCLUSIONS: Administration of dexmedetomidine after congenital cardiac surgery was not associated with any increase in pulmonary artery pressure.

The management of hypoplastic left heart syndrome with a right aortic arch.

The combination of hypoplastic left heart syndrome and a right-sided aortic arch is extremely rare and lethal. To the best of our knowledge, no patient with this combination has previously been reported as surviving initial palliation. The anatomic variant is associated with abnormalities in the arteries branching from the aortic arch, making it difficult to construct a reliable source of flow of blood to the lungs. We present here a patient with this combination who survived an initial Damus-Kay-Stansel procedure combined with placement of a conduit from the right ventricle to the pulmonary arteries, and who has subsequently undergone a successful bidirectional cavopulmonary anastomosis. We believe that the conduit placed from the right ventricle provides the most reliable source of flow of blood to the lungs at the time of initial palliation in this usual combination of cardiac lesions.

Neonatal congestive heart failure due to a subclavian artery to subclavian vein fistula diagnosed by noninvasive procedures.

UNLABELLED: Congestive heart failure in the neonate is usually due to intracardiac anomalies or cardiac dysfunction. Extracardiac causes are rare. PATIENT: We report a newborn infant who presented with respiratory distress and cardiomegaly. RESULT: Echocardiography identified a dilated right subclavian artery and vein and superior vena cava. Magnetic resonance imaging confirmed a subclavian artery to subclavian vein fistula that was treated with surgical ligation. The infant recovered fully. This case underscores the need for clinical suspicion of fistulous connection in unusual locations in the face of unexplained heart failure in the neonate. CONCLUSION: Echocardiographic and magnetic resonance imaging are effective noninvasive modalities to confirm the diagnosis prior to surgical intervention.