Shubhika Srivastava

Multisite near-infrared spectroscopy predicts elevated blood lactate level in children after cardiac surgery.

OBJECTIVES To determine if a relationship exists between regional oxyhemoglobin saturation (rSO(2)) measured at various body locations by near-infrared spectroscopy (NIRS) and blood lactate level in children after cardiac surgery. DESIGN A prospective, observational study. SETTING A pediatric cardiac intensive care unit in a university hospital. PARTICIPANTS Twenty-three children undergoing repair of congenital heart disease. Patients with single-ventricle physiology and/or residual intracardiac shunts were excluded. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS Cerebral, splanchnic, renal, and muscle rSO(2) values were recorded every 30 seconds via NIRS for 24 hours postoperatively. Blood lactate levels measured minimally at 0, 2, 4, 6 and 24 hours postoperatively were correlated with rSO(2) values derived by averaging all values recorded during the 60 minutes preceding the blood draw. Twenty-three patients were enrolled with 163 lactate measurements and more than 39,000 rSO(2) observations analyzed. Cerebral rSO(2) had the strongest inverse correlation with lactate level followed by splanchnic, renal, and muscle rSO(2) (r = -0.74, p < 0.0001, r = -0.61, p < 0.0001, r = -0.57, p < 0.0001, and r = -0.48, p < 0.0001, respectively). The correlation improved by averaging the cerebral and renal rSO(2) values (r = -0.82, p < 0.0001). Furthermore, an averaged cerebral and renal rSO(2) value <or=65% predicted a lactate level >or=3.0 mmol/L with a sensitivity of 95% and a specificity of 83% (p = 0.0001). CONCLUSIONS Averaged cerebral and renal rSO(2) less than 65% as measured by NIRS predicts hyperlactatemia (>3 mmol/L) in acyanotic children after congenital heart surgery. Hence, this noninvasive, continuous monitoring tool may facilitate the identification of global hypoperfusion caused by low cardiac output syndrome in this population.

Extubation in the operating room after congenital heart surgery in children

OBJECTIVE Early extubation in the operating room after surgery for congenital heart disease has been described; however, postoperative mechanical ventilation in the intensive care unit remains common practice in many institutions. The goal of this study was to identify perioperative factors associated with not proceeding with planned operating room extubation. METHODS We performed a retrospective chart review of 224 patients (aged 1 month to 18 years, median 20 months) undergoing surgery for congenital heart defects requiring cardiopulmonary bypass. Patients mechanically ventilated preoperatively were excluded. A stepwise logistic regression model was used to test for the independent influence of various perioperative factors on extubation in the operating room. RESULTS Overall, 79% of patients were extubated in the operating room. Younger age and longer cardiopulmonary bypass time were the strongest predictors for not extubating. Each step down to a younger age group (<2, 2-4, 4-6, 6-12, >12 months) reduced the chance of extubation in the operating room by 56%. Cardiopulmonary bypass time for more than 150 minutes was associated with an 11.8-fold increased risk of not being extubated. Male gender and high inotrope requirement after cardiopulmonary bypass were also significantly associated with fewer children being extubated. CONCLUSION Extubation in the operating room after surgery for congenital heart disease was successful in the majority of patients. The strongest independent risk factors for failure of this strategy included younger age and longer cardiopulmonary bypass time.

High prevalence of structural heart disease in children with cblC-type methylmalonic aciduria and homocystinuria.

OBJECTIVE To characterize the frequency and nature of cardiovascular defects in patients with CblC-type methylmalonic aciduria and homocystinuria (cblC), an inborn error of cobalamin (vitamin B12) metabolism resulting in accumulation of methylmalonic acid and homocysteine. STUDY DESIGN A retrospective observational study was conducted investigating 10 patients with cblC ranging in age from 2 weeks to 24 years (mean 4.4 years +/- 7.5 years, median 0.6 years). All patients underwent a complete 2-D echocardiogram including quantitative assessment of left ventricular systolic function. RESULTS Structural heart defects were detected in 50% of patients with cblC. Heart defects included left ventricular (LV) non-compaction (3), secundum atrial septal defect (2), muscular ventricular septal defect (1), dysplastic pulmonary valve without pulmonary stenosis (1) and mitral valve prolapse with mild mitral regurgitation (1). One patient had resolved cor pulmonale and right heart failure secondary to pulmonary embolism. All patients had quantitatively normal LV systolic function. CONCLUSIONS Diverse and clinically significant structural heart defects appear to be highly prevalent in cblC, perhaps due to abnormal DNA and histone methylation during embryogenesis. The specific cardiac defects detected in our cohort were variable, and studies with a larger number of patients are needed to establish which forms are most common. Routine and periodic cardiovascular evaluation may be indicated in patients with cblC.

Near Infrared Spectroscopy (NIRS) in Children

Near infrared spectroscopy (NIRS) is a noninvasive method for the in vivo monitoring of tissue oxygenation. Originally used predominantly to assess cerebral oxygenation, NIRS has gained widespread popularity in many clinical settings in all age groups. Changes in regional tissue oxygenation as detected by NIRS may reflect the delicate balance between oxygen delivery and consumption in more than one organ system. However, more studies are required to establish the ability of NIRS monitoring to improve patient outcome. This review provides a comprehensive description of NIRS in children.

Echocardiographic Methods, Quality Review, and Measurement Accuracy in a Randomized Multicenter Clinical Trial of Marfan Syndrome

BACKGROUND The Pediatric Heart Network is conducting a large international randomized trial to compare aortic root growth and other cardiovascular outcomes in 608 subjects with Marfan syndrome randomized to receive atenolol or losartan for 3 years. The authors report here the echocardiographic methods and baseline echocardiographic characteristics of the randomized subjects, describe the interobserver agreement of aortic measurements, and identify factors influencing agreement. METHODS Individuals aged 6 months to 25 years who met the original Ghent criteria and had body surface area-adjusted maximum aortic root diameter (ROOTmax) Z scores > 3 were eligible for inclusion. The primary outcome measure for the trial is the change over time in ROOTmaxZ score. A detailed echocardiographic protocol was established and implemented across 22 centers, with an extensive training and quality review process. RESULTS Interobserver agreement for the aortic measurements was excellent, with intraclass correlation coefficients ranging from 0.921 to 0.989. Lower interobserver percentage error in ROOTmax measurements was independently associated (model R(2) = 0.15) with better image quality (P = .002) and later study reading date (P < .001). Echocardiographic characteristics of the randomized subjects did not differ by treatment arm. Subjects with ROOTmaxZ scores ≥ 4.5 (36%) were more likely to have mitral valve prolapse and dilation of the main pulmonary artery and left ventricle, but there were no differences in aortic regurgitation, aortic stiffness indices, mitral regurgitation, or left ventricular function compared with subjects with ROOTmaxZ scores < 4.5. CONCLUSIONS The echocardiographic methodology, training, and quality review process resulted in a robust evaluation of aortic root dimensions, with excellent reproducibility.

Relation of Coarctation of the Aorta to the Occurrence of Ascending Aortic Dilation in Children and Young Adults With Bicuspid Aortic Valves

Children with bicuspid aortic valve (BAV) have aortic dilation that is present and progressive from birth irrespective of the functional state of the valve. There are no published data comparing aortic dilation in children with BAV with and without aortic coarctation (CoA). The objectives of this study were to (1) compare differences in aortic dimensions and rates of dilation between children with isolated BAV with those of children with BAV and CoA and (2) identify risk factors for the development of aortic dilation. Patients with BAV with CoA (group A) and without CoA (group B) were identified from our echocardiographic database (1993 to 2006). Aortic measurements at 4 levels were obtained, and z scores were compared. Criteria for exclusion were severe aortic regurgitation/stenosis, previous aortic valvuloplasty, complex left-sided cardiac disease, ventricular septal defects, and Turner, Noonan, Williams, and Marfan syndromes. There were 600 echocardiograms in 247 patients. Group A had 192 echocardiograms in 53 patients (median age 11.3 years; range 0 to 30; median follow-up 7 years), and group B had 382 in 194 patients (median age 8.7 years; range 0 to 29; median follow-up 4 years). Group B had significantly greater ascending aorta dimensions (p<0.05) and significantly faster rates of aortic dilation (p<0.0001). The ascending aorta in patients with BAV and CoA did not dilate to the same degree as in patients with isolated BAV. In conclusion, valve morphologic characteristics and function and age at CoA repair had none to minimal impact on aortic dimensions.

Phelan-McDermid syndrome: a review of the literature and practice parameters for medical assessment and monitoring

Autism spectrum disorder (ASD) and intellectual disability (ID) can be caused by mutations in a large number of genes. One example is SHANK3 on the terminal end of chromosome 22q. Loss of one functional copy of SHANK3 results in 22q13 deletion syndrome or Phelan-McDermid syndrome (PMS) and causes a monogenic form of ASD and/or ID with a frequency of 0.5% to 2% of cases. SHANK3 is the critical gene in this syndrome, and its loss results in disruption of synaptic function. With chromosomal microarray analyses now a standard of care in the assessment of ASD and developmental delay, and with the emergence of whole exome and whole genome sequencing in this context, identification of PMS in routine clinical settings will increase significantly. However, PMS remains a rare disorder, and the majority of physicians have never seen a case. While there is agreement about core deficits of PMS, there have been no established parameters to guide evaluation and medical monitoring of the syndrome. Evaluations must include a thorough history and physical and dysmorphology examination. Neurological deficits, including the presence of seizures and structural brain abnormalities should be assessed as well as motor deficits. Endocrine, renal, cardiac, and gastrointestinal problems all require assessment and monitoring in addition to the risk of recurring infections, dental and vision problems, and lymphedema. Finally, all patients should have cognitive, behavioral, and ASD evaluations. The objective of this paper is to address this gap in the literature and establish recommendations to assess the medical, genetic, and neurological features of PMS.

Frequency of Aberrant Subclavian Artery, Arch Laterality, and Associated Intracardiac Anomalies Detected by Echocardiography

Tetralogy of Fallot is generally considered to be the most common congenital heart defect associated with an aberrant subclavian artery (ASA), but the prevalence of ASA in patients with other cardiac anomalies is not well described. The pediatric echocardiography database, with 15,871 initial echocardiograms, was searched for all patients with ASA. Arch laterality and associated intracardiac anomalies were documented for each patient. ASA was found in 226 patients, of whom 171 had a left aortic arch (LAA) and 55 had a right aortic arch (RAA). The occurrence of ASA was 1% in patients with LAA (171 of 15,650) and 25% in patients with RAA (55 of 221; p = 0.001). Intracardiac anatomy was normal in 32% of patients with ASA/LAA and 25% with ASA/RAA. Conotruncal anomalies occurred more frequently with ASA/RAA than ASA/LAA (36% vs 18%; p = 0.01). Atrioventricular canal defects accounted for 10% and left-sided cardiac obstructive lesions accounted for 11% of subjects with ASA/LAA. ASA was rarely associated with d-transposition of the great arteries (1 of 226) and double-outlet right ventricle (5 of 226). The prevalence of ASA was highest in patients with interrupted aortic arch (11 of 38; 29%). In patients with tetralogy of Fallot, the overall prevalence of ASA was 8% (34 of 447), but was higher with RAA (16 of 103; 16%). The highest prevalence of ASA occurred in the subgroup of patients with tetralogy of Fallot with pulmonary atresia and RAA (6 of 25; 24%). In conclusion, ASA was more common in patients with RAA, especially with conotruncal anomalies. In patients with LAA, hypoplastic left heart syndrome, aortic coarctation, and atrioventricular canal defects were commonly associated with ASA.

Use of 3-Dimensional Printing to Demonstrate Complex Intracardiac Relationships in Double-Outlet Right Ventricle for Surgical Planning

Double-outlet right ventricle falls under the category of congenital heart disease known as conotruncal defects, which possess abnormal ventriculoarterial relationships.1 For complex cases, the surgeon must determine whether the left ventricle and one of the great arteries can be aligned using the ventricular septal defect to construct an unobstructed pathway or baffle, resulting in a 2-ventricle repair.2 Creation of the baffle can be complicated by anatomic obstructions because of prominent conal septum, straddling atrioventricular valve attachments, or location of the ventricular septal defect in the inlet septum, remote from any great artery. Three-dimensional (3D) printing has been applied in the management of many different congenital heart diseases.3 In this specific patient population, in whom communicating the complex intracardiac anatomy to the surgeon is so critical, the use of 3D modeling and printing is invaluable. We used this approach in a patient with dextrocardia, complex double-outlet right ventricle (S,L,A)1 and supratricuspid ring. She underwent pulmonary artery banding in infancy and had been doing relatively well clinically; so that any further surgical intervention was deferred until she was 8 years old. Although she was growing well and required no medication, …

Incidences and sociodemographics of specific congenital heart diseases in the United States of America: an evaluation of hospital discharge diagnoses.

Current estimates of the incidence of congenital heart disease (CHD) are derived from small clinical studies and metaanalyses. For the true incidence of CHD in the United States of America to be estimated, a single large representative population must be analyzed. All the data in this study were derived from the Nationwide Inpatient Sample database. The study determined the overall and lesion-specific incidences of CHD diagnoses among all birth hospitalizations in 2008, stratified by race, gender, socioeconomic status, and hospital geographic location. The study identified 13,093 CHD diagnoses among 1,204,887 birth hospitalizations, yielding an incidence of 10.8 per 1,000, with a predominance of mild lesions and septal defects. Atrial septal defect (ASD) and pulmonic stenosis were more common among females, whereas aortic stenosis, coarctation of the aorta, hypoplastic left heart syndrome, and d-transposition of great arteries were more common among males. No racial difference was observed in the overall CHD incidence. However, isolated patent ductus arteriosus (PDA) and ventricular septal defects (VSDs) were more common among Caucasians, whereas ASDs were more common among Hispanics. The incidences of CHD diagnoses were similar for all socioeconomic classes except the lowest socioeconomic class, which had a significantly lower CHD incidence. There was no geographic or seasonal variation in CHD incidence. This study demonstrated the incidence of echocardiographically confirmed CHD diagnosis to be 10.8 per 1,000 live births, marked by a high proportion of mild cardiac lesions and isolated PDAs. The high incidence of isolated PDAs in this study may be explained by the inclusion of only CHD diagnoses during birth hospitalization.