Inhaled Nitric Oxide and Higher Necrotizing Enterocolitis Rates in Congenital Heart Disease Patients.

INTRODUCTION: Certain congenital cardiac lesions are at increased risk for the development of necrotizing enterocolitis (NEC). These patients are often reliant on pulmonary and systemic vasomodulators to maintain adequate perfusion and oxygenation. This study sought to determine whether pulmonary or systemic vasodilator treatment is protective against the development of NEC in this population. METHODS: We utilized International Classification of Diseases (ICD) codes to identify high risk congenital cardiac disease patients ≤6 mo of age, cared for at a tertiary children's hospital between January 2011 and January 2021. Cardiac anomalies were stratified into ductal dependent (pulmonary DD-P or systemic DD-S) or independent lesions. The rate of NEC development in those who received vasodilators (inhaled nitric oxide [iNO], pulmonary vasodilators, systemic vasodilators) was compared to controls in a multivariate analysis. RESULTS: Of the 352 patients, who met inclusion criteria, 77.6% had ductal dependent lesions (DD-S 41.9%, DD-P 35.7%), 19.5% received iNO, and 37.5% received other vasodilatory drugs. The overall NEC rate was 15.1%. On univariate analysis, DD-S, iNO use, and systemic vasodilators was associated with a significantly higher risk of NEC, while DD-P was associated with lower NEC risk. On multivariate analysis, only iNO (odds ratio 2.725, confidence interval [1.36-5.44]) and DD-S (odds ratio 2.279, confidence interval [1.02-5.11]) were independent risk factors for NEC. CONCLUSIONS: In patients with at-risk congenital cardiac disease lesions, a ductus dependent systemic circulation or iNO treatment is associated with an increased risk of developing NEC. The presence of iNO or DD-S should be utilized as markers of increased risk both in the prevention and workup of suspected NEC.

Management of Hypertrophic Cardiomyopathy in a Newborn with Dextro-Transposition of the Great Arteries.

Impaired maternal glucose metabolism during pregnancy can have significant effects on the cardiovascular system of the developing fetus. Early in pregnancy the teratogenic effects may lead to structural heart defects, while later in gestation a form of hypertrophic cardiomyopathy can develop due to overgrowth driven by fetal hyperinsulinism. We describe an infant with the uncommon combination of both dextro-transposition of the great arteries and hypertrophic cardiomyopathy. We emphasize the importance of a longitudinal multi-disciplinary approach, from fetal diagnosis to post-operative management, that allowed for an excellent outcome in this rare combination of severe cardiac malformations.

Tricuspid Valve and Right Ventricular Function Throughout the Hybrid Palliation Strategy for Hypoplastic Left Heart Syndrome and Variants.

BACKGROUND: Tricuspid valve (TV) and right ventricular (RV) function are major determinants of morbidity and mortality in patients with hypoplastic left heart syndrome (HLHS). We sought to retrospectively evaluate these parameters throughout the hybrid palliation strategy. METHODS: From 2002 to 2018, 203 patients with HLHS and variants presented for hybrid stage I (HS1). Echocardiographic evaluation of tricuspid regurgitation (TR) and RV function was assessed at multiple time points. Clinical outcomes including tricuspid valvuloplasty, transplantation, and death were reviewed. RESULTS: The most prevalent HLHS subtype was aortic atresia/mitral atresia. The presence of significant TR and/or RV dysfunction was 14.78% and 9.36%, respectively, at the time of initial HS1. There were 185 survivors following HS1 (91.13%, n = 185/203), while 147 patients underwent comprehensive stage II or bidirectional Glenn shunt (72.41%, n = 147/203). Tricuspid valvuloplasty was undertaken in nine patients (4.86%, n = 9/185). Ultimately, 100 patients underwent the Fontan procedure. The odds of development of significant TR and/or RV dysfunction were not statistically different throughout the stages of palliation (TR: odds ratio [OR] = 0.14-0.25, P = .5260; RV dysfunction: OR = 0.02-0.13, P = .3992). However, the risk of death and/or transplant was 2.5- to 3.8-fold when either were present alone or in combination (TR: OR = 2.58, P = .0356; RV dysfunction: OR = 3.84, P = .0262). Transplant-free survival at 15 years was 44.8%. CONCLUSION: Following hybrid palliation for HLHS, the majority of survivors have normal RV and TV functions. Tricuspid valvuloplasty was required in few patients. Once significant TR and/or RV dysfunction ensues, there is a two- to three-fold risk of death and/or transplant.

Launching a New Strategy for Multidisciplinary Management of Single-Ventricle Heart Defects.

Children born with single-ventricle heart defects, particularly hypoplastic left heart syndrome, have a lifetime high risk of mortality and comorbidities. They have complex medical challenges in addition to their cardiac needs, including growth and feeding complications and neurodevelopmental issues. These concerns require a coordinated effort among specialties to help patients maximize their potential. Additionally, because many complex heart defects are diagnosed prenatally, coordination of care between the pre- and postnatal care teams is imperative. Nursing leadership improves program coordination and efficiency. The purpose of this article is to describe the development and implementation of our hospital's synchronized, multidisciplinary team to support children with single-ventricle heart defects and their families. (Critical Care Nurse. 2018;38[1]:60-71).

QRS duration and mechanical dyssynchrony correlations with right ventricular function after fontan procedure.

BACKGROUND: In studies of adult patients, increased QRS duration and mechanical dyssynchrony have been associated with decreased ventricular function. The aim of this study was to test the hypothesis that similar findings would be present in a population of patients with hypoplastic left heart syndrome (HLHS) after the Fontan procedure. METHODS: A retrospective cross-sectional study was conducted. All patients with HLHS after the Fontan procedure were eligible. QRS duration was measured using 12-lead electrocardiography. Echocardiographic measurements of mechanical dyssynchrony included Doppler tissue imaging (DTI) QRS to onset of s' wave difference between the left ventricle and the right ventricle, time to peak strain, time to peak systolic strain rate (SRs), the standard deviation of time to peak strain rate (modified Yu strain), and the standard deviation of time to peak SRs (modified Yu SRs). Right ventricular (RV) functional measurements included DTI s' wave, DTI RV myocardial performance index, global strain, global SRs, and RV fractional area change. Pearson's correlations were performed between the variables. RESULTS: Thirty-one echocardiographic studies were performed on 26 patients. The median age was 5.3 years (range, 2.5-15.4 years). QRS duration was correlated significantly with global SRs (r = 0.42). Time to peak SRs was correlated significantly with DTI s' wave (r = -0.48) and global SRs (r = 0.37). Modified Yu SRs was correlated significantly with global strain (r = 0.35) and RV fractional area change (r = -0.35). CONCLUSIONS: Both QRS duration and mechanical dyssynchrony were correlated with RV function, albeit weakly. The clinical significance of these findings is intriguing, but only larger studies will determine if these measurements are reliable in guiding treatment options for this complex patient population.

Strain echocardiographic assessment of ventricular function after percutaneous pulmonary valve implantation.

INTRODUCTION: Percutaneous pulmonary valve implantation (PPVI) is an emerging therapy for pulmonary valve dysfunction. Minimal data on the midterm effects of PPVI on ventricular function exist. We describe the effects of PPVI on right and left ventricular (RV, LV) function with speckle tracking echocardiography. METHODS: Patients who met the inclusion criteria of the Food and Drug Administration Phase 1 Feasibility Clinical Trial PPVI were identified. Patients were studied with echocardiograms at baseline, post-PPVI (day of discharge), 3 months, and at 6 months. Patients were studied by cardiac magnetic resonance at baseline and at 6 months. Longitudinal strain was measured at the basal, mid, and apical portions of the RV, interventricular septum (IVS), and LV. Global RV and LV strain and strain rates were recorded. Paired t-tests were used for analysis. RESULTS: Ten patients were analyzed: nine patients were a variant of tetralogy of Fallot and one patient had complex LV outflow obstruction requiring a Ross and RV-pulmonary atresia conduit. Mean age was 24.4 ± 7.6 years. Indication for PPVI was pulmonary regurgitation in six patients, stenosis in two patients, and stenosis/regurgitation in two patients. After PPVI, both RV systolic pressure and RV to pulmonary artery pressure gradient significantly decreased. Cardiac magnetic resonance RV end-diastolic volume significantly decreased. IVS-mid, IVS-apical, and LV-global strain significantly increased and RV-basal decreased immediately after PPVI. Global RV a' strain rate significantly increased immediately after PPVI. However, RV, IVS, and LV strain/strain rate values between baseline and the 6 month echocardiographic study were either similar or significantly decreased. CONCLUSION: Despite improvement in RV hemodynamics, there was a decrease or no improvement in RV and LV function as measured by strain echocardiographic values at midterm follow-up. Larger studies with longer follow-up are needed to determine if these results remain consistent.

Transcatheter elimination of left-to-right shunts in infants with bronchopulmonary dysplasia is feasible and safe.

OBJECTIVE: To test the hypothesis that transcatheter elimination of left-to-right (L-R) cardiac shunts in former premature infants with bronchopulmonary dysplasia (BPD) is feasible, safe, and is associated with an improvement in respiratory status. DESIGN: Retrospective case review. PATIENTS: Twelve patients with BPD who underwent an attempt at transcatheter closure of an L-R shunt lesion within the first year of life at a single center. Median weight was 5.4 kg and median age was 6 months. Fifteen L-R shunt lesions included patent ductus arteriosus (n = 1), atrial septal defect (ASD) (n = 9), and aortopulmonary collaterals (n = 5). OUTCOME MEASURES: Echocardiographic and clinical markers were collected before and after intervention as well as procedural variables including successful elimination of the shunt and procedural complications. RESULTS: The L-R shunts were successfully occluded in 11/12 (91.6%) patients without any significant procedural adverse event. The ASD closure group demonstrated a decrease in right heart size after the procedure. All patients required respiratory support prior to, and 1 month after, the procedure while only 5/10 (50%) required respiratory support at 12 months of age (P = .0129). There was no change in the median weight percentile over time. CONCLUSION: Transcatheter occlusion of L-R shunts can be performed safely and effectively in children with BPD. Further studies may clarify the role of such therapy in improvement in respiratory physiology over time.

Echocardiographic assessment of atrial properties in single ventricles vs. normal controls.

INTRODUCTION: Atrial function is increasingly being recognized as a significant factor in overall cardiac function in adults. Limited studies evaluating atrial properties exist in the pediatric congenital heart disease population. The goal of this study was to evaluate atrial properties in patients with single ventricle physiology after Fontan completion and compare these values with normal control patients. METHODS: Echocardiograms were performed in patients with single ventricular physiology and in control patients. Tissue Doppler and blood flow measurements were obtained. Atrial fraction and atrial electromechanical values were calculated. Differences were assessed with one-way analysis of variance. Post hoc comparisons were performed with Tukey adjustment. P < .05 was considered significant. RESULTS: No significant difference was present in age or heart rate between single ventricle and control patients. The single right ventricle tricuspid valve A wave (52.6 ± 14.5 vs. 36.7 ± 10.4 cm/s) and atrial fraction (39.2 ± 6.2 vs. 32.7 ± 7.7%) were significantly higher, and the E/A ratio (1.4 + 0.3 vs. 1.8 + 0.4), tricuspid valve E/A velocity-time integral (1.6 + 0.4 vs. 2.2 + 0.7 cm), and late diastolic annular value (5.3 + 1.5 vs. 8.7 + 1.4 cm/s) were significantly lower compared with the controls. The single left ventricle late diastolic annular velocity (4.2 + 1.0 vs. 6.7 + 1.3 cm/s) was significantly lower and atrial fraction was significantly higher compared with the controls (37.7 ± 12.5 vs. 29.8 ± 4.3%). There were no significant differences in atrial electromechanical measurements between groups, but the single right ventricle patients tended to have increased atrial dyssynchrony compared with controls. CONCLUSIONS: Patients with single ventricle physiology after Fontan completion have differences in atrial properties when compared with normal controls. These differences may have important implications in their long-term outcomes. Further studies are necessary to determine the clinical significance of these findings.

Two-dimensional speckle strain and dyssynchrony in single left ventricles vs. normal left ventricles.

BACKGROUND: Patients with single left ventricle (LV) physiology maybe at increased risk for myocardial dysfunction and mechanical dyssynchrony. Newer echocardiographic modalities may be able to better quantitate LV function in this unique population. Our objective was to use 2D-speckle analysis of strain and strain rate to quantify systolic function and dyssynchrony in single LV post-Fontan patients and compare them to control LV patients. METHODS: Patients with single LV status post-Fontan procedure and patients with normal biventricular anatomy were studied. Two-dimensional speckle echocardiography was used to measure strain, strain rate, time to peak, and longitudinal displacement in a six-segment model of the LV. Independent t-tests were used to compare group means. RESULTS: Twelve patients with single LV physiology and thirteen control patients were studied. There was no significant difference in ages for the single LV patients vs. control patients (7.1 + 2.8 years vs. 5.7 + 1.8 years). Single LV strain values were significantly lower in four of the six segments compared with control LV (mid interventricular septal [IVS]: -19.3 + 6.4% vs. -23.8 + 3.5%, apical IVS: -20.8 + 5.4% vs. -27.4 + 4.7%, basal LV: -20.6 + 6.6% vs. -25.8 + 3.4%, and apical LV: -21.0 + 6.2% vs. -26.1 + 4.3%). Longitudinal displacement was lower for all three segments of the IVS for the single LV vs. control LV. Modified Yu index for strain and strain rate time to peak was longer in the single LV patients vs. controls (51.2 + 18.2 ms vs. 27.9 + 8.0 ms and 90.2 + 24.2 ms vs. 52.5 + 23.7 ms, respectively). CONCLUSION: Significant differences in strain analysis between single LV patients vs. control patients with normal biventricular physiology exist at a relatively young age. Future studies are needed to determine the significance of these differences.

Differences in tissue Doppler imaging between single ventricles after the fontan operation and normal controls.

Tissue Doppler imaging measurements could be used to quantitate ventricular function in patients with systemic single ventricles. The objective of the present study was to measure the tissue doppler imaging-derived indexes of function and dyssynchrony in patients with single ventricular physiology and compare these values with those from control patients. Echocardiograms were performed in patients with single left or right ventricular physiology and control patients. Measurements were made of the free walls at the level of the atrioventricular annulus. Differences were assessed with one-way analysis of variance. Post hoc comparisons were performed with a Tukey adjustment. No significant difference was present in age among the control (5.75 +/- 1.73 years, n = 16), single left ventricle (7.07 +/- 2.81 years, n = 12), or single right ventricle (6.25 +/- 2.2 years, n = 14) groups. The single right ventricular free wall peak systolic annular, peak early diastolic annular, and peak late diastolic annular velocities were significantly lower and the myocardial performance index and interval to mechanical activation greater compared to the controls. The single left ventricular free wall peak systolic annular, peak early diastolic annular, and peak late diastolic annular velocities were also significantly lower and the myocardial performance index and interval to mechanical activation greater compared to controls. In conclusion, significant decreases in systolic and diastolic function, as well as differences in dyssynchrony, using tissue Doppler imaging exist in patients with single ventricular physiology compared to control patients.

Two-dimensional speckle strain and dyssynchrony in single right ventricles versus normal right ventricles.

BACKGROUND: Patients with single-right ventricle (RV) physiology are at increased risk for myocardial dysfunction and mechanical dyssynchrony. Newer echocardiographic modalities may be better able to quantitate right ventricular function in this unique population. The aim of this study was to use two-dimensional speckle analysis of strain and strain rate to quantify systolic function and dyssynchrony in single-RV post-Fontan patients and compare them with values for controls. METHODS: Patients with single RV who underwent Fontan palliation and patients with normal biventricular anatomy were studied. Two-dimensional speckle echocardiography was used to measure strain, strain rate, time to peak, and longitudinal displacement in a 6-segment model of the RV. Independent t tests were used to compare group means. P values < .05 were considered significant. RESULTS: Thirteen patients were studied in each group. There was no significant difference in age between single-RV patients and controls (6.60 +/- 2.07 vs 5.75 +/- 1.83 years, respectively). Single-RV strain values were significantly lower in all 6 segments compared with values in controls (basal interventricular septum [IVS], -14.28 +/- 7.78% vs -22.00 +/- 2.36%; mid IVS, -17.70 +/- 4.54% vs -22.99 +/- 2.71%; apical IVS, -19.46 +/- 4.97% vs -25.42 +/- 4.06%; basal RV, -22.40 +/- 5.7% vs -41.42 +/- 5.42%; mid RV, -21.20 +/- 3.21% vs -39.67 +/- 6.04%; apical RV, -20.70 +/- 4.90% vs -33.68 +/- 3.90%). Systolic strain rate and longitudinal displacement were also lower in the free wall and apical IVS in single-RV patients compared with controls. The modified Yu index for strain time to peak was longer in the single-RV patients (43.16 +/- 13.63 vs 21.72 +/- 7.25 ms). CONCLUSION: Significant differences in strain analysis between single-RV patients and patients with biventricular physiology exist at a relatively young age. Future studies are needed to determine the clinical significance of these differences.

Successful use of bivalirudin for superior vena cava recanalization and stent placement in a child with heparin-induced thrombocytopenia.

Heparin-induced thrombocytopenia (HIT) is a potentially life-threatening, adverse effect of heparin therapy. Patients with this complication require an alternative approach to anticoagulation. Bivalirudin is a direct thrombin inhibitor with an efficacy comparable to that of heparin, a short half-life, and reduced bleeding complications in adults. We present the case of a 2-year-old boy with HIT Type II who underwent recanalization of an occluded superior vena cava and stent placement, utilizing bivalirudin as anticoagulant.

Atrial flutter in infants.

OBJECTIVES: We sought to characterize the clinical nature of atrial flutter (AFL) in a large cohort of infants. BACKGROUND: There are no large studies describing the natural history of AFL in infants. Previous studies vary in the therapy used and expected prognosis. METHODS: We reviewed the records of all children younger than 1 year of age who were diagnosed with AFL at our hospital during the past 25 years, excluding those with previous cardiac surgery. RESULTS: We identified 50 infants with AFL. Most, 36 (72%), presented within the first 48 h of life. Congestive heart failure was evident in 10 infants, with 6 presenting at 1 day of age, and 4 presenting beyond 1 month of age. The remainder were asymptomatic. A large atrial septal defect was the only structural heart disease. Spontaneous conversion to sinus rhythm occurred in 13 (26%) infants. Sinus rhythm was restored in 20 of 23 (87%) attempts at direct current cardioversion and 7 of 22 (32%) attempts at transesophegeal pacing; 7 required antiarrhythmic therapy. An additional arrhythmia, all supraventricular, appeared in 11 (22%) infants. The recurrence of AFL developed in 6 infants; 5 of 6 of these incidents occurred within 24 h of the first episode. All patients with recurrence had an additional arrhythmia. CONCLUSIONS: Infants with AFL usually present within the first 2 days of life. No association was found with structural heart disease. Direct current cardioversion appears to be most effective at establishing sinus rhythm. Chronic AFL has the potential to cause cardiovascular compromise. Atrial flutter in the absence of other arrhythmias has a low risk of recurrence. Once in sinus rhythm, infants with AFL have an excellent prognosis and may not require chronic antiarrhythmic therapy.