Balloon Angioplasty for Native Aortic Coarctation in 3- to 12-Month-Old Infants.

BACKGROUND: Balloon angioplasty for native coarctation of the aorta (CoA) is successful in children and adults but in neonates results in frequent restenosis. The efficacy of balloon angioplasty for native CoA during infancy beyond the neonatal period was examined in infants aged 3 to 12 months of age. METHODS: A retrospective review of 68 infants who underwent balloon angioplasty for native CoA. 95% CI are in parentheses. RESULTS: Procedural age was (mean±SD) 6±3.4 months and weight was 7±1.8 kg. Balloon angioplasty produced a large decrease in both the noninvasive arm-to-leg blood pressure gradient (41.2±18.7 to 5.6±9.6 mm Hg) and the invasive peak systolic pressure gradient (34±12 to 11±9 mm Hg). Balloon angioplasty increased the CoA diameter from 2.7±1 mm to 4.6±1.2 mm. One patient was lost to follow-up. A catheter reintervention was required in 11.8% and surgery in 10.3%. The hazard of reintervention was highest early. Median freedom from reintervention was 89% (95% CI, 80%-96%) at 1 year, 83% (95% CI, 73%-92%) at 5 years, and 81% (95% CI, 69%-90%) at 10 years. Femoral artery thrombosis was documented in 6 (9%) infants without any long-term consequence. One patient developed a small aortic aneurysm late and has not required treatment. A robust estimate of the frequency of aortic aneurysms remains to be determined as the majority of subjects have not had cross-sectional imaging. CONCLUSIONS: Balloon angioplasty of native CoA is effective and safe in infants aged 3 to 12 months with outcomes comparable to those in older children and adults. Catheter reinterventions can avoid the need for surgery in most patients.

Infective endocarditis associated with acute leukemia: Report of two cases.

There have been few reports regarding infective endocarditis (IE) in patients with leukemia. In the first case, a 15-year-old girl with Down syndrome was diagnosed with acute lymphoblastic leukemia. On admission, methicillin-sensitive Staphylococcus aureus (MSSA) was detected on blood culture. Echocardiography was performed because MSSA was detected repeatedly even after treatment. Vegetation in all of the atria and ventricles met the Duke criteria defining IE. She died of multiple organ failure 21 days after diagnosis. In the second case, an 11-year-old boy with acute myeloid leukemia underwent peripheral blood stem cell transplantation (PBSCT). He had fever 68 days after PBSCT, and methicillin-resistant S. aureus (MRSA) was detected on blood culture. Echocardiography showed vegetation in the right atrium and ventricle. Daptomycin was administered for 7 weeks, and recurrence was not observed. IE should be considered when S. aureus bacteremia is documented even in patients with leukemia.

Survival implications: hypertrophic cardiomyopathy in Noonan syndrome.

OBJECTIVES: To understand relationships and survival implications between structural heart disease and hypertrophic cardiomyopathy in Noonan syndrome (Noonan syndrome-HCM), we reviewed the clinical course of 138 children with Noonan syndrome diagnosed with cardiovascular abnormalities and compared survival with the 30 children with Noonan syndrome-HCM with 120 contemporaneous children with nonsyndromic HCM. METHODS: Study cohorts represent consecutive cases diagnosed at our institution 1966 through 2006. Outcomes were modeled using multiphase parametric techniques followed by multivariable regression with bagging. RESULTS: Cardiac abnormalities in Noonan syndrome: Cardiac abnormalities in the 138 Noonan syndrome children included pulmonary valve dysplasia (52%), hypertrophic cardiomyopathy (22%), atrial septal defect (20%), ventricular septal defect (10%), mitral valve dysplasia (6%), coarctation (3%), and Fallot's tetralogy (2%). Need for surgery was high but not different from children with structural defects coexisting with HCM. Overall, late survival in children with Noonan syndrome and cardiac defects was good (91 ± 3% at 15 years), although significantly worse for those with Noonan syndrome-HCM (P < .01). Noonan syndrome-HCM vs. nonsyndromic HCM: In the 30 children with Noonan syndrome-HCM, structural cardiac malformations coexisted in 18 (57%). The incidence of structural cardiac malformations in nonsyndromic HCM was instead 3/120 (2.5%, P < .001). Risk-adjusted late survival was significantly worse for Noonan syndrome-HCM than for nonsyndromic HCM (P= .02). CONCLUSIONS: Noonan syndrome-HCM frequently coexists with structural cardiac malformations, whereas nonsyndromic HCM does not; their natural histories may therefore be different. Late survival is significantly worse for Noonan syndrome-HCM than nonsyndromic HCM.

Critical care outcomes in pulmonary atresia and intact ventricular septum undergoing single-ventricle palliation.

OBJECTIVE: To examine early outcomes for pulmonary atresia with intact ventricular septum undergoing single-ventricle palliation and to determine risk factors for mortality. DESIGN: Retrospective observational study. SETTING: Tertiary paediatric critical care unit. INTERVENTION: Risk factors for mortality were sought for infants after the primary intervention whether surgical shunt or ductal stent. MEASUREMENTS AND MAIN RESULTS: We reviewed outcomes of 19 infants with pulmonary atresia with intact ventricular septum undergoing single-ventricle palliation between July, 2000 and July, 2008. Echocardiograms, cardiac catheterisation findings, anaesthesia, and critical care management, as well as autopsy reports were reviewed. We modelled survival after surgery and looked for predictors of early mortality. A total of 19 infants underwent single-ventricle palliation and seven of these died. The risk of death was increased by a lower arterial pH at induction of anaesthesia (p = 0.01), a lower systolic blood pressure (p = 0.01), and technical problems during surgery (p = 0.03). On admission to the critical care unit, a lower mixed venous saturation (p = 0.02) and presence of tachyarrhythmia (p = 0.02) were associated with the need for mechanical support within the first 48 hours. CONCLUSIONS: There is a high early mortality for those who undergo single-ventricle palliation. It is higher for those who are haemodynamically compromised before surgery; technical problems, and haemodynamic instability during surgery also increase mortality.

Percutaneous pulmonary valve implantation within bioprosthetic valves.

AIMS: Replacement of bioprosthetic valves in the right ventricular (RV) outflow tract (RVOT) is inevitable due to acquired valvar dysfunction. Percutaneous pulmonary valve implantation (PPVI) may result in acceptable clinical improvement avoiding surgical reintervention. To report outcomes of PPVI in dysfunctional surgically implanted bioprosthetic valves. METHODS AND RESULTS: All children undergoing PPVI into a bioprosthetic pulmonary valve between October 2005 and February 2008 were reviewed. Acute haemodynamic changes were compared and an analysis of variance applied to assess changes in ventricular geometry and pressure over time. Fourteen children (seven males), median weight 57.8 kg and 14.7 years of age were identified, with an echocardiographic RVOT gradient of 59.6 +/- 26.8 mmHg and a pulmonary regurgitation (PR) grade of 3.6 +/- 0.8 (out of 4). Implantation was successful in all. Twenty-four hours after implantation, there was a significant improvement in RV pressure (RVP) (from 82.2 +/- 15.6 to 59.4 +/- 9.9 mmHg, P < 0.001) and degree of PR to 0.6 +/- 0.9 (P < 0.001). Mean hospital stay was 2.0 +/- 0.4 days. Freedom from reintervention was 92 and 89% at 1 and 2 years, respectively. Follow-up echocardiography (mean 12.9 +/- 9.8 months) revealed a further reduction in RVP (P < 0.001) and RVOT gradients (P < 0.001) and an increase in left ventricular end-diastolic volume (P= 0.01) and aortic valve annulus diameters (P < 0.001). CONCLUSIONS: Percutaneous pulmonary valve implantation for RVOT dysfunction in a previously implanted prosthetic valve is feasible and safe. Short-term follow-up data are encouraging, yet longer-term information is required to determine if this form of palliation has a significant impact on management strategies.

Antenatal glucocorticoid therapy accelerates ATP production with creatine kinase increase in the growth-enhanced fetal rat heart.

BACKGROUND: Previous study has demonstrated the increase of several cardiac function-related proteins, including creatine kinase (CK) as an important enzyme in the process of ATP synthesis in the fetal heart of rats administered glucocorticoid (GC) antenatally. In the present study the effect of antenatal GC administration on the CK expression in fetal and neonatal hearts was demonstrated. METHODS AND RESULTS: Dexamethasone was administered to pregnant rats on days 19 and 20 of gestation. The mRNA levels of the CK isoforms, CK-M and Mi-CK, in 21-day-old fetal and 1-day-old neonatal hearts were significantly increased after antenatal GC administration. CK protein levels were also increased in both cultured cardiomyocytes and the mitochondria of the hearts. Uptake of 5, 5', 6, 6'-tetrachloro-1, 1', 3, 3'-tetraethyl-benzimidazolocarbocyanine iodide by mitochondria was significantly increased. An increased ATP level accompanied the CK increase in the neonatal hearts. Furthermore, in vitro these effects were mediated though the GC receptor of cardiomyocytes. Peroxisome proliferator-activated receptor gamma as the upstream transcription factor of CK was significantly increased in fetal hearts. CONCLUSIONS: These results suggest that antenatal GC administration accelerates ATP synthesis through increased CK and may contribute to maturation of the premature heart so that it is ready for preterm delivery. (Circ J 2010; 74: 171 - 180).

Effect of transcatheter pulmonary valve implantation on short-term right ventricular function as determined by two-dimensional speckle tracking strain and strain rate imaging.

Transcatheter pulmonary valve implantation (PVI) is an emerging therapy for right ventricular (RV) outflow dysfunction in congenital heart disease. We investigated, for the first time in children after surgery for congenital heart disease, the short-term effects of PVI on RV and left ventricular (LV) function using 2-dimensional speckle tracking echocardiography and tissue Doppler imaging. We hypothesized that the short-term RV and LV function would improve. Two-dimensional speckle tracking echocardiograms and pulsed tissue Doppler images were obtained before and 1 to 2 days after PVI (18-mm Melody valve). The catheter right heart hemodynamics were recorded. The strain and strain rate of the basal lateral left ventricle, lateral right ventricle, and interventricular septum were measured by 2-dimensional speckle tracking echo, and the pre- and postprocedure values were compared. Of the 16 eligible patients (age 16 +/- 2 years), the scans of 10 had correct image format and adequate quality. PVI was performed for volume (n = 4) or combined pressure-volume (n = 6) loading. After PVI, the RV to pulmonary artery pressure gradient (33 +/- 22 to 12 +/- 4 mm Hg, p = 0.02), pulmonary regurgitation, and RV end-diastolic volume (3.2 +/- 0.8 to 2.8 +/- 0.6 cm, p = 0.02) decreased, and the septal systolic velocities (3.5 +/- 1.1 to 4.7 +/- 1.1 cm/s, p = 0.04), strain (-7.6 +/- 9.3% to -15.6% +/- 6.7%, p = 0.01) and strain rate (-0.3 +/- 1.1 to -1.1 +/- 0.5 1/s, p = 0.04) and RV free wall strain increased (-17.4 +/- 8.6% to -23.4% +/- 6.2%, p = 0.03). The LV tissue velocities, strain, and strain rate were unchanged. In conclusion, PVI leads to RV unloading and acutely improves RV and septal function.

Antenatal glucocorticoid therapy increase cardiac alpha-enolase levels in fetus and neonate rats.

AIMS: Antenatal glucocorticoid therapy has been shown to prevent acute diseases including infant respiratory distress syndrome and reduce mortality, although little is known about the effects on cardiac function-related proteins in the fetus or neonate. We investigated whether cardiac function-related proteins were altered in cardiac tissues of fetuses and neonates born to pregnant rats treated by glucocorticoid. MAIN METHODS: Dexamethasone (DEX) was administered to pregnant rats for 2 days on day 17 and 18 or day 19 and 20 of gestation to simulate antenatal DEX therapy, and cardiac tissues of 19- and 21-day fetuses and 1-, 3-, and 5-day neonates were analyzed using a proteomic technique with liquid chromatography-mass spectrometry/mass spectrometry. KEY FINDINGS: The identified five proteins; alpha-enolase, creatine kinase-M type, beta-tubulin, troponin T, and ATP synthase beta-chain, were significantly increased in fetal cardiac tissues with DEX administration. We observed that significant increase of alpha-enolase in the 19-day fetuses by DEX using Western blotting and immunohistochemistry. ATP and cAMP levels were also increased in the fetal heart tissue. In addition, pyruvate levels were significantly increased in the fetus groups by DEX. SIGNIFICANCE: These results suggest that increased alpha-enolase may contribute to acceleration of glycolysis in the preterm heart.

Balloon dilation of pulmonary valve stenosis in infants less than 3 kg: a 20-year experience.

OBJECTIVES: This study focused on the anatomical features and outcomes of percutaneous pulmonary valve balloon dilation (PVD) in newborns < or = 3 kg in weight. BACKGROUND: Although PVD is the treatment of choice for isolated pulmonary valve stenosis, there are no studies detailing technical, anatomical, and outcome variables in the smallest of infants undergoing the procedure. METHODS: A retrospective, consecutive review of all initial and follow-up echocardiograms, catheterization data, cineangiograms, and surgical records of all neonates less than 3 kg. RESULTS: Fifty infants underwent 55 PVD's, median age 7 days and weight 2.7 kg. Congestive heart failure and/or cyanosis were present in 55%, 46% prostaglandin dependent, with 28% having a hypoplastic right ventricle. The pulmonary valve diameter median z-score was -2.6, (range -5.8 to 1.2, P < 0.0001 vs. normal). The procedure was accomplished in all but one child, using a balloon to annulus ratio of 1.3 (range 1.1 to 1.7). There was a reduction in both the peak right ventricular systolic pressure (P < 0.0001) and outflow gradient (P < 0.0001). There was no procedure related mortality, although six children died in long-term follow-up (14%). Reintervention was necessary in 15 infants within 8 months of the procedure. Pulmonary regurgitation, present in 36% after the procedure, showed a gradual increase over time while outflow gradients decreased and valve annular dimensions increased toward normal. CONCLUSIONS: In infants < or = 3 kg, PVD is safe and effective. A large proportion remains free from surgery (76% at 10 years). Small valve annular dimensions show catch up growth with time.

Outcomes of emergent cardiac catheterization following pediatric cardiac surgery.

BACKGROUND: Although there is agreement of the importance of cardiac catheterization, especially interventional procedures, cardiac catheterization in postoperative critical care unit (CCU) period is often debated. The focus of this study was to explore the indications for and determinants of outcome after cardiac catheterization in this setting. METHODS: Between March 2004 and October 2006, 49 children (2.8% of cardiac surgeries) underwent 62 catheterizations before discharge from the CCU. Morphological, surgical, and catheterization data were accrued and analyzed using parametric competing risks models and multivariable risk-hazard analysis. RESULTS: Median age at surgery was 167 days (0-13.5 years) and time to catheterization was 8.5 (0-84) days following surgery. Catheterization procedures were either interventional (n = 35) or noninterventional (n = 27). Children who required a more urgent investigation following initial surgery more often had deployment of a stent at catheterization (P = 0.01) or subsequent surgical pulmonary artery augmentation (P < 0.01). Surgical reoperation was required following 23 (37%) catheterizations and was more common following index surgery involving a cavopulmonary shunt. Overall mortality was high (43%). Delayed invasive investigation beyond 2-3 weeks (P = 0.04) or a splinted sternum (P < 0.001) were risk factors for death. In addition, reoperation after a noninterventional catheterization predicted worse survival (P < 0.001). CONCLUSIONS: The need for invasive investigation in the immediate CCU period is associated with a poor outcome, especially when the investigation is delayed or an intervention is not possible. Identification of at-risk patients may improve outcomes. Best outcomes follow expedient catheterization with definitive management (often stent deployment or pulmonary artery augmentation).