Stacey Drant

Bubble contrast echocardiography in detecting pulmonary arteriovenous shunting in children with univentricular heart after cavopulmonary anastomosis.

OBJECTIVES We sought to compare bubble contrast echocardiography and pulmonary angiography in detecting pulmonary arteriovenous malformation (PAVM) in children with cavopulmonary anastomosis (CPA), and to examine anatomic and physiologic variables associated with the development of PAVM. BACKGROUND Development of PAVM in patients with CPA may cause profound cyanosis. Pulmonary arteriovenous malformation has been traditionally diagnosed by pulmonary angiography with reported incidence of 20% to 25% in patients with CPA. METHODS Fourteen patients (age 1.1 to 12.6 years) with any forms of CPA and normal pulmonary venous drainage formed the study population. All patients underwent cardiac catheterization and pulmonary angiography. Bubble contrast echocardiographic studies were performed with injection of 10 ml of agitated saline solution into branch pulmonary arteries. Transthoracic echocardiograms using an apical view were performed to assess the appearance of bubble contrast in the systemic ventricles. We compared the results of pulmonary angiograms and contrast echocardiograms, and findings of contrast echocardiograms between lungs with hepatic venous blood flow and lungs without hepatic venous blood. RESULTS Ten of the 14 patients (71%) had positive contrast echocardiographic studies, compared with three (21%) detected by pulmonary angiograms (p = 0.01). No difference was found in pulmonary artery pressure, transpulmonary gradient or presence of heterotaxy syndrome between patients with positive contrast echocardiographic studies and patients with negative studies. However, patients with positive contrast echocardiograms tended to have lower oxygen saturation (81%) and higher hemoglobin (16.4 g/dl) compared with patients with negative studies (88% and 14.7 g/dl, p = 0.10 and p = 0.18 respectively). Patients with Glenn shunt or unidirectional Fontan had higher incidence of PAVM (10/11) compared with patients with classic or lateral tunnel Fontan (0/3, p = 0.01). All 12 lungs with no perfusion of hepatic venous blood had positive contrast echocardiographic studies. Lungs with no hepatic venous blood flow were more likely to develop PAVM compared with lungs with hepatic venous blood flow (12/12 and 3/16 respectively, p < 0.01). CONCLUSIONS Bubble contrast echocardiography is more sensitive in detecting PAVM compared with pulmonary angiography. The prevalence of PAVM in patients with CPA may be much higher than what had been reported previously. Lungs with no hepatic venous blood flow are more likely to develop PAVM than lungs with hepatic venous blood flow.

Diagnosis of heterotaxy syndrome by fetal echocardiography

We report a series of 13 consecutive patients diagnosed in utero with heterotaxy syndrome in which we found a slight predominance (8 of 13) of fetuses with right atrial isomerism. In previous studies in which diagnosis of left or right isomerism was made based upon findings at fetal echocardiography, there has been a preponderance of infants (95%) diagnosed with left isomerism.

Prevalence of Congenital Cardiovascular Malformations in Children of Human Immunodeficiency Virus-Infected Women: The Prospective P2C2 HIV Multicenter Study

OBJECTIVES The purpose of the study was to assess the effects of maternal HIV-1 (human immunodeficiency virus) infection and vertically transmitted HIV-1 infection on the prevalence of congenital cardiovascular malformations in children. BACKGROUND In the United States, an estimated 7000 children are born to HIV-infected women annually. Previous limited reports have suggested an increase in the prevalence of congenital cardiovascular malformations in vertically transmitted HIV-infected children. METHODS In a prospective longitudinal multicenter study, diagnostic echocardiograms were performed at 4-6-month intervals on two cohorts of children exposed to maternal HIV-1 infection: 1) a Neonatal Cohort of 90 HIV-infected, 449 HIV-uninfected and 19 HIV-indeterminate children; and 2) an Older HIV-Infected Cohort of 201 children with vertically transmitted HIV-1 infection recruited after 28 days of age. RESULTS In the Neonatal Cohort, 36 lesions were seen in 36 patients, yielding an overall congenital cardiovascular malformation prevalence of 6.5% (36/558), with a 8.9% (8/90) prevalence in HIV-infected children and a 5.6% (25/449) prevalence in HIV-uninfected children. Two children (2/558, 0.4%) had cyanotic lesions. In the Older HIV-Infected Cohort, there was a congenital cardiovascular malformation prevalence of 7.5% (15/201). The distribution of lesions did not differ significantly between the groups. CONCLUSIONS There was no statistically significant difference in congenital cardiovascular malformation prevalence in HIV-infected versus HIV-uninfected children born to HIV-infected women. With the use of early screening echocardiography, rates of congenital cardiovascular malformations in both the HIV-infected and HIV-uninfected children were five- to ten-fold higher than rates reported in population-based epidemiologic studies but not higher than in normal populations similarly screened. Potentially important subclinical congenital cardiovascular malformations were detected.

Echocardiographic findings of hypertrophic cardiomyopathy in children after orthotopic liver transplantation

Abstract: This study was carried out to compare echocardiographic findings of children taking tacrolimus and cyclosporin A (CsA) after orthotopic liver transplantation (OLT). Echocardiograms of 19 children were reviewed during hospitalizations after OLT, and echocardiograms were performed on 23 children who returned to the clinic for a routine follow‐up visit after OLT. Measurements were made of the left ventricle (LV) end‐diastolic dimension, and of the thickness of the LV free wall (LVFW) and the inter‐ventricular septum (IVS). From these measurements, the LV mass was calculated. LV outflow gradient was measured by using Doppler interrogation. Comparisons were made between patients on CsA and patients on tacrolimus. Children with hypertrophic cardiomyopathy (HCM) were identified. Two patients from the in‐patient tacrolimus group were found to have HCM. These two patients had asymmetric septal hypertrophy with dynamic LV outflow obstruction and were successfully treated with propranolol, with or without discontinuing tacrolimus. In the out‐patient studies, there was no difference in LVFW and IVS thickness, or LV mass index, between children on CsA and children on tacrolimus. Hence, tacrolimus is associated with the development of HCM in children. The effect of tacrolimus on HCM development may be acute and temporary. More data are needed to determine the incidence of HCM in children on tacrolimus therapy and to establish guidelines for clinicians who follow‐up these children.

Aortic to right ventricular shunt for pulmonary atresia and intact ventricular septum.

Acute or chronic myocardial ischemia may develop in patients with pulmonary atresia with intact ventricular septum and right ventricular-dependent coronary circulation. In such cases an aorta to right ventricle shunt may be used to reverse this ischemia. This report summarizes our experience with the placement of an aortic to right ventricular shunt in 5 patients. The shunts were made of Gore-Tex and ranged from 4 mm to 8 mm. Associated procedures were bidirectional Glenn (n = 2) and Fontan (n = 2). All 5 patients survived the procedure with documented early graft patency and no evidence of ischemia.

Guidance of radiofrequency catheter ablation by transesophageal echocardiography in children with palliated single ventricle

Abstract In summary, biplane TEE contributed significantly to successful radiofrequency catheter ablation in 6 patients with palliated single ventricle by allowing catheter positioning that may not have been possible under fluoroscopy alone, by monitoring catheter stability during application of current, and by providing immediate information regarding the presence or absence of early postablation complications.

The use of Doppler tissue imaging to predict cellular and antibody-mediated rejection in pediatric heart transplant recipients

Abstract: DTI indices have been associated with cellular rejection in adult heart transplant recipients, but their predictive value in pediatric recipients is unknown. The purpose of this study was to evaluate DTI measures in the detection of cellular and AMR in pediatric heart transplant recipients. One hundred and forty‐eight pediatric heart transplant recipients who had 267 cardiac catheterization procedures with EMB, echocardiogram with DTI, and BNP level performed on the same day were included in the study. For the mitral and tricuspid valves, the ratios (E/E’) between the early diastolic inflow velocity by pulsed Doppler (E, m/s) and the early diastolic annular velocity by DTI (E’, m/s) were obtained and compared between subjects with and without rejection. Of the 148 recipients, 30 subjects had a total of 37 episodes of rejection: 10 cellular (≥1B), 17 AMR, and 10 biopsy‐negative clinical rejection. Mitral and tricuspid valve E/E’ ratios were significantly higher in rejectors than in non‐rejectors (5.5 ± 1.3 vs. 4.4 ± 1.4, p < 0.001 and 4.9 ± 2.1 vs. 4.1 ± 1.5, p < 0.01, respectively). By multivariate linear regression, mitral valve E/E’ was an independent predictor of rejection. Mitral and tricuspid valve E/E’ <5.0 had 93% and 89% NPV, respectively, for rejection. Mitral and tricuspid valve E/E’ ratios <5.0 may be useful non‐invasive screening measures to exclude rejection in pediatric heart transplant recipients.

Prevalence of congenital cardiovascular malformations in children of human immunodeficiency virus-infected women

OBJECTIVES The purpose of the study was to assess the effects of maternal HIV-1 (human immunodeficiency virus) infection and vertically transmitted HIV-1 infection on the prevalence of congenital cardiovascular malformations in children. BACKGROUND In the United States, an estimated 7000 children are born to HIV-infected women annually. Previous limited reports have suggested an increase in the prevalence of congenital cardiovascular malformations in vertically transmitted HIV-infected children. METHODS In a prospective longitudinal multicenter study, diagnostic echocardiograms were performed at 4-6-month intervals on two cohorts of children exposed to maternal HIV-1 infection: 1) a Neonatal Cohort of 90 HIV-infected, 449 HIV-uninfected and 19 HIV-indeterminate children; and 2) an Older HIV-Infected Cohort of 201 children with vertically transmitted HIV-1 infection recruited after 28 days of age. RESULTS In the Neonatal Cohort, 36 lesions were seen in 36 patients, yielding an overall congenital cardiovascular malformation prevalence of 6.5% (36/558), with a 8.9% (8/90) prevalence in HIV-infected children and a 5.6% (25/449) prevalence in HIV-uninfected children. Two children (2/558, 0.4%) had cyanotic lesions. In the Older HIV-Infected Cohort, there was a congenital cardiovascular malformation prevalence of 7.5% (15/201). The distribution of lesions did not differ significantly between the groups. CONCLUSIONS There was no statistically significant difference in congenital cardiovascular malformation prevalence in HIV-infected versus HIV-uninfected children born to HIV-infected women. With the use of early screening echocardiography, rates of congenital cardiovascular malformations in both the HIV-infected and HIV-uninfected children were five- to ten-fold higher than rates reported in population-based epidemiologic studies but not higher than in normal populations similarly screened. Potentially important subclinical congenital cardiovascular malformations were detected.

The echocardiographic evaluation of pulmonary atresia with intact ventricular septum

Abstract Echocardiography has become an integral tool for the diagnosis of pulmonary atresia with intact ventricular septum in both the fetus and the neonate. The echocardiographic assessment has become of paramount importance for decision-making regarding the type of intervention necessary. Patients can be stratified based primarily upon the tricuspid valve Z -score and right ventricular infundibular anatomy into those patients in whom the pulmonary valve can be opened and by which method. Patients with tricuspid valve Z -scores of >−2.5 have been shown to have almost no risk of having a right ventricular-dependent coronary system and have a high likelihood of achieving a biventricular repair. Those with a patent infundibulum can achieve right ventricular decompression via surgical valvotomy or valvuloplasty in the catheterization lab. Those with a tapering infundibulum generally require an outflow tract patch. Echocardiography is employed after right ventricular decompression to assess: (1) the need for an additional shunt; (2) adequacy of right ventricular decompression; (3) right ventricular growth; and (4) assessment of left ventricular function.

Diffuse myocardial fibrosis among healthy pediatric heart transplant recipients: Correlation of histology, cardiovascular magnetic resonance, and clinical phenotype

Fibrosis is commonly described in heart allografts lost late after transplantation. CMR‐derived ECV is a validated measure of DMF in native adult hearts that may predict heart failure and mortality. We explored associations of ECV with histologic myocardial fibrosis and clinical features after pediatric heart transplantation. Twenty‐five recipients (7.0±6.3 years at transplant and 10.7±6.5 years post‐transplant) were prospectively recruited for CMR and BNP measurement at the time of surveillance biopsy. All had normal ejection fractions and lacked heart failure symptoms. Fibrosis was quantified on biopsy after picrosirius red staining as CVF. ECV was quantified using contemporaneous hematocrit on basal and mid‐short‐axis slices. ECV was moderately correlated with CVF (r=.47; P=.019). We found no associations of ECV with hemodynamics, ischemic time, time since transplantation, or number of prior biopsies or acute rejections. Compared to healthy non‐transplant controls, there was no significant difference in ECV (25.1±3.0 vs 23.7±2.0%, P=.09). Log‐transformed BNP was correlated with ECV (recipients: r=.46, P=.02; recipients and controls: r=.45, P=.006). These findings suggest ECV quantifies DMF and relates to biological indicators of cardiac function after pediatric heart transplantation.