Robert L. Spicer

Sudden death in Williams syndrome: Report of ten cases☆☆☆★

Williams syndrome (WS) is a recognizable pattern of malformation with mental retardation, mild growth deficiency, characteristic facies and temperament, and cardiovascular disease. Sudden death is a recognized complication of WS; however, it is thought to be rare. The clinical features of 10 children with WS who died suddenly are reported here, doubling the number of unexpected deaths reported in the literature. We suggest that sudden death is a more common complication than has been assumed previously. Pathologic findings on the seven autopsy cases implicate two anatomic abnormalities that predispose individuals with WS to sudden death: coronary artery stenosis and severe biventricular outflow tract obstruction. The mechanisms for sudden death for both anatomic subgroups include myocardial ischemia, decreased cardiac output, and arrhythmia. We believe these observations warrant the development of strategies for monitoring patients with WS in an attempt to identify those at increased risk of sudden death.

Percutaneous balloon angioplasty for native coarctation of the aorta

Twenty-six children, aged 5 weeks to 14.7 years, underwent percutaneous balloon angioplasty for a discrete native coarctation of the aorta. The procedure reduced the systolic coarctation gradient acutely in all children. The mean systolic gradient decreased by 75%, from 48.6 +/- 2.4 before to 12.3 +/- 1.9 mm Hg after angioplasty (p less than 0.001). Long-term results were evaluated in 14 children by follow-up catheterization 12 to 26 months (mean 15.3) after angioplasty. At follow-up, the residual gradient averaged 11.7 +/- 3.7 mm Hg (range -5 to 36) and had not changed from that measured immediately after angioplasty (p = 0.64). Compared with preangioplasty values, the systolic pressure in the ascending aorta had improved substantially at follow-up (116.0 +/- 3.2 versus 143.9 +/- 3.1 mm Hg, p less than 0.001). On the basis of follow-up data, two groups of children were identified: Group 1 consisted of nine children with a good result, defined as a residual gradient less than 20 mm Hg and no aneurysm; Group 2 consisted of five children with a poor result, four with a residual gradient greater than 20 mm Hg (range 25 to 36) and one with an aneurysm at the dilation site. There was no statistical difference between the two groups in age at angioplasty, balloon size, ratio of balloon to isthmus diameters, follow-up duration, heart rate or cardiac output. However, of the four children with a residual gradient greater than 20 mm Hg, two were the youngest in the study, and in two the aorta was inadvertently dilated with a balloon 4 to 5 mm smaller than the isthmus diameter.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortopulmonary collateral vessels and prolonged pleural effusions after modified Fontan procedures

Pleural effusions after the modified Fontan procedure are unpredictable, increase morbidity, and prolong hospital stay. To assess the relation between preoperative characteristics and postoperative pleural drainage, we performed a retrospective study of 71 patients who underwent Fontan procedures. Analyses revealed no significant relation between duration of effusion and age at Fontan, preoperative oxygen saturation, pulmonary artery pressure, ventricular end-diastolic pressure, type of Fontan, or prior cavopulmonary anastomosis. Patients with significant aortopulmonary collateral vessels evidenced by angiographic opacification of the pulmonary arteries or veins had more prolonged pleural drainage. The duration of the pleural drainage was significantly less in patients who had aortopulmonary collateral occlusion.

Steroid Therapy and Cardiac Function in Duchenne Muscular Dystrophy

Duchenne muscular dystrophy leads to progressive deterioration in skeletal and cardiac muscle function. Steroids prolong ambulation and improve respiratory muscle strength. The authors hypothesized that steroid treatment would stabilize cardiac muscle function. Echocardiograms performed from 1997 to 2004 for 111 subjects 21 years of age or younger with Duchenne muscular dystrophy were restrospectively reviewed. The medical record was reviewed for steroid treatment. Untreated and steroids-treated subjects did not differ in age, height, weight, body mass index, systolic and diastolic blood pressure, or left ventricular mass. The shortening fraction was lower in the untreated group. Of those treated, 29 received prednisone and 19 received deflazacort. There was no difference in the shortening fraction between the two treated subgroups. Treated subjects not receiving steroids still had a normal shortening fraction, which was no different from the shortening fraction of those still receiving treatment. As compared with the treated subjects, the untreated subjects 10 years of age or younger were 4.4 times more likely to have a shortening fraction less than< 28% (p = 0.03), and the untreated subjects older than 10 years were 15.2 times more likely to have a shortening fraction less than< 28% (p < 0.01). This retrospective study suggests that the progressive decline in cardiac function of patients with Duchenne muscular dystrophy can be altered by steroid treatment. The effect appears to be sustained beyond the duration of treatment and independent of steroid type.

Neurodevelopmental outcomes in children with Fontan repair of functional single ventricle

Objectives. The purpose of this study was to assess the neurodevelopmental status of children after Fontan repair of functional single ventricle and to examine the relationship between cognitive function and selected patient characteristics. Study Design. Neurodevelopmental tests including the Stanford-Binet Intelligence (IQ) scale and the Developmental Test of Visual Motor Integration (VMI) were administered to 32 children (26 months to 16 years of age) with complex single ventricle. The mean and distribution of IQ and VMI scores were compared with population norms. The relationship between test scores and patient characteristics was examined utilizing analysis of variance and correlational methods. Results. The majority of children had intellectual function within the normal range (mean, 97.5 ± 12.1). Below average VMI scores were found in 21.4% of children. There were no significant correlations between intellectual function or visual motor integration ability and preoperative oxygen saturation or age at Fontan. Children who had deep hypothermic circulatory arrest during a prior Norwood procedure tended to have a lower IQ score. Conclusions. Intellectual development in children with Fontan repair of complex heart defects is essentially within the normal range. Visual motor integration deficits may be more prevalent in these children. In our population, the duration and degree of preoperative hypoxemia had no apparent effect on cognitive function.

Color M-Mode and Doppler Tissue Evaluation of Diastolic Function in Children: Simultaneous Correlation with Invasive Indices

OBJECTIVE The purpose of this study was to explore the validity of diastolic indices derived from color M-mode Doppler and Doppler tissue imaging in a heterogeneous group of pediatric patients by comparing them with simultaneously obtained invasive indices of diastolic function. METHODS A total of 20 children undergoing left heart catheterization had echocardiographic images recorded simultaneously with high-fidelity left ventricular (LV) pressure tracings. Transmitral Doppler, pulmonary vein Doppler, Doppler tissue imaging, and color M-mode Doppler flow propagation velocity were recorded. LV peak negative dP/dt, the time constant of isovolumic relaxation, and LV end-diastolic pressure were compared with the echocardiographic indices. RESULTS The ratio of peak E-wave mitral velocity/propagation velocity correlated significantly with LV end-diastolic pressure (r = 0.71; P <.001). Propagation velocity correlated with the time constant of isovolumic relaxation (r = -0.56; P =.01) and peak negative dP/dt (r = 0.50; P <.03). Septal mitral annular myocardial velocity correlated significantly with the time constant of isovolumic relaxation (r = -0.58, P =.01). CONCLUSION The newer diastolic indices derived from color M-mode Doppler and Doppler tissue imaging appear to be a helpful adjunct in the noninvasive assessment of diastolic function in children.

Health-Related Quality of Life in Children and Adolescents With Duchenne Muscular Dystrophy

OBJECTIVES: The purpose of this study was to assess health-related quality of life (QoL) in children with Duchenne muscular dystrophy (DMD), including development and field-testing of a DMD-specific module integrated with the core Pediatric Quality of Life Inventory (PedsQL). METHODS: The PedsQL 4.0 Generic Core and DMD Module Scales were completed by 203 families, including 200 parents and 117 boys with DMD. Scores on the PedsQL Core Scales were compared with those of matched healthy children. Relationships between PedsQL scores and patient characteristics were examined. RESULTS: By both parent report and child self-report, mean PedsQL scores for boys with DMD were significantly lower than those for healthy children for physical and psychosocial QoL (P < .0001), with significantly impaired psychosocial QoL scores self-reported by 57%. Psychosocial QoL, by self-report only, tended to be higher in the older boys (13–18 years) than in younger boys (8–12 years; P = .05) and was not significantly associated with use of mobility aids. Although parents reported higher Daily Activities scores in boys receiving steroids (P = .01), boys receiving steroids reported no difference in Daily Activities but significantly less worry (P = .004). Parent–child concordance was generally in the fair to poor range. Internal consistency reliability coefficients for PedsQL DMD module scales ranged from 0.66 to 0.86. CONCLUSIONS: Overall, boys with DMD reported significantly lower QoL than their healthy peers. Despite decreased physical functioning, older boys seem to perceive better psychosocial QoL than perceived by their parents and by younger boys, unrelated to their need for mobility aids.

Outcomes of Children With Cardiomyopathy Listed for Transplant: A Multi-institutional Study

BACKGROUND Dilated (DCM), restrictive (RCM), and hypertrophic (HCM) cardiomyopathies (CM) in children have varying clinical courses and therapeutic options. Heart transplantation (HTx) offers a chance for long-term survival; but outcomes after listing have not been well defined. METHODS A multi-institutional registry of 3,147 patients listed for HTx (January 1993-December 2006) was used to compare outcomes of 1,320 children with CM (42%) and 1,827 with non-CM (58%) etiologies. Comparisons were made between sub-groups: 1,098 DCM (83%), 145 RCM (11%), and 77 HCM (6%). RESULTS CM patients had a waitlist mortality of 17% vs 32% for non-CM patients (p < 0.0001), with no difference between the CM sub-groups. Risk factors were younger age, black race (relative risk [RR], 1.65; p = 0.009), mechanical ventilation (RR, 3.17; p < 0.001), and extracorporeal membrane oxygenation (RR, 2.16; p < 0.001). Ten-year survival after listing was 66% for CM vs 53% for non-CM (p < 0.0001). HCM and RCM patients aged < 1 year at the time of listing had the highest waitlist mortality and the lowest overall survival. CM patients had a better 10-year survival after HTx (68% vs 61%, p < 0.0001). Risk factors for death early after HTx included mechanical ventilation at HTx (RR, 3.07; p < 0.001), longer ischemic time (RR, 1.27; p = 0.01), and earlier era (RR, 1.77; p = 0.002). Late risk factors included black race (RR, 3.01; p < 0.001), HCM or RCM (RR, 1.93; p = 0.007), and older age (RR, 1.9; p < 0.001). CONCLUSION Children with CM have a lower waitlist mortality and better survival post-HTx than children with a non-CM diagnosis. DCM patients have the best and HCM or RCM patients aged younger than 1 year have the worst overall outcomes.

Factors influencing perioperative morbidity during palliation of the univentricular heart

BACKGROUND The modified Fontan procedure has become the treatment of choice for patients born with a univentricular heart. Although the operative mortality has steadily decreased in recent years, the hospital stay is still prolonged in many patients due to fluid retention and pleural effusions. METHODS We retrospectively analyzed subsets of patients undergoing the bidirectional cavopulmonary shunt (BDCPS) and modified Fontan procedure in an attempt to define factors influencing operative mortality and morbidity. RESULTS Multivariate analysis of 64 patients undergoing BDCPS revealed that age 6 months or less, concomitant operation, mean pulmonary pressure of 15 mm Hg or less, and mean pulmonary artery ratio of 1.8:1 or less were not statistically significant indicators of risk. Abnormal pulmonary artery architecture was a significant predictor of early and late death (p < or = 0.01). Retrospective analysis of 71 patients undergoing the modified Fontan procedure revealed no significant relationship between duration of pleural effusions and age at operation, preoperative oxygen saturation, pulmonary artery pressure, ventricular end-diastolic pressure, or prior BDCPS: Patients with important aortopulmonary collateral vessels defined by angiography had prolonged pleural drainage. Selective use of the total extracardiac conduit and the fenestrated Fontan resulted in low overall mortality with no statistical differences between subsets of patients undergoing different modifications of the Fontan procedure. CONCLUSIONS These data indicate that the operative risk for BDCPS or modified Fontan procedure is quite low if a procedure appropriate for the patient is selected. Abnormal pulmonary artery architecture is an important risk factor for death after the BDCPS: Aortopulmonary collateral vessels are associated with fluid retention and pleural effusions after a modified Fontan procedure. Important aortopulmonary collateral vessels should be occluded before or during the modified Fontan procedure.

Pediatric cardiomyopathy: importance of genetic and metabolic evaluation.

BACKGROUND Cardiomyopathy is a heterogeneous disease with a strong genetic component. A research-based pediatric cardiomyopathy registry identified familial, syndromic, or metabolic causes in 30% of children. However, these results predated clinical genetic testing. METHODS AND RESULTS We determined the prevalence of familial, syndromic, or metabolic causes in 83 consecutive unrelated patients referred for genetic evaluation of cardiomyopathy from 2006 to 2009. Seventy-six percent of probands (n = 63) were categorized as familial, syndromic, or metabolic. Forty-three percent (n = 18) of hypertrophic cardiomyopathy (HCM) patients had mutations in sarcomeric genes, with MYH7 and MYBPC3 mutations predominating. Syndromic (17%; n = 7) and metabolic (26%; n = 11) causes were frequently identified in HCM patients. The metabolic subgroup was differentiated by decreased endocardial shortening fraction on echocardiography. Dilated cardiomyopathy (DCM) patients had similar rates of syndromic (20%; n = 5) and metabolic (16%; n = 4) causes, but fewer familial cases (24%; n = 6) compared with HCM patients. CONCLUSIONS The cause of cardiomyopathy is identifiable in a majority of affected children. An underlying metabolic or syndromic cause is identified in >35% of children with HCM or DCM. Identification of etiology is important for management, family-based risk assessment, and screening.