Iodixanol pharmacokinetics in children.

The objective of this report was to study the elimination pharmacokinetics of iodixanol in children. Iodixanol (Visipaque, Nycomed Inc., Wayne, PA, USA) is a new iso-osmolar iodinated radiocontrast agent. We hypothesized that elimination of this agent would be dependent on age-related differences in renal clearance. Seven centers enrolled 43 patients. Cardiac catheterization was performed in 41 patients and cranial computed tomography in 2. Patients were entered into 5 age groups: newborn to <2 months, 2 to <6 months, 6 months to <1 year, 1 to <3 years, and 3 to 6 months of age that is comparable to normal adults. Prolonged elimination in children <6 months of age is related to renal immaturity.

Percutaneous transcatheter occlusion of coronary artery fistulas using detachable balloons.

Three pediatric patients underwent successful transcatheter coronary artery fistula occlusion using the Debrun system. This latex balloon system offers several advantages over other occlusion systems. First, the balloon delivery and release is controlled. Second, "test occlusions" can be performed that allow simultaneous balloon inflation, coronary cineangiography, and electrocardiographic monitoring. Third, because the balloons are flow-directed, they are easily positioned in properly chosen locations. Finally, the balloons can be constructed to suit the size of the fistula. In this study, two patients received only one balloon; in the other patient two balloons were placed in the same fistula. All fistulas drained into either the right atrium or ventricle and were successfully occluded. After a follow-up period of up to 3 years, no local or systemic reactions to the balloons were recognized. We conclude that detachable balloon occlusion of coronary artery fistulas is a safe, effective alternative to surgical ligation in selected pediatric patients.

Tricuspid atresia and annular hypoplasia: report of a familial occurrence.

Occurrence of a similar cardiac malformation in multiple family members has been reported for many lesions. Neither tricuspid atresia nor tricuspid annular hypoplasia and tricuspid atresia has been described in multiple members of the same family. We report two cases of tricuspid atresia and one case of tricuspid annular hypoplasia with an atrial septal defect in siblings. The findings in this family suggest an autosomal recessive pattern of inheritance for abnormal tricuspid valve morphogenesis.

Familial atrioventricular septal defect: possible genetic mechanisms.

BACKGROUND: Most non-chromosomal congenital heart defects are thought to be caused by the interaction of genetic factors involving multiple genes and environmental factors. Families that have several affected members have been reported, however, which suggests that a single autosomal dominant or recessive gene may cause the cardiac defects. A family in which atrioventricular septal defect seemed to be a single gene disorder is reported. OBSERVATIONS: A family in which the mother and her two daughters from different fathers had atrioventricular septal defect not associated with trisomy 21 is reported. CONCLUSIONS: This family raises the possibility that cytoplasmic or mitochondrial inheritance may be involved in the causation of atrioventricular septal defects. The available data from pedigrees from other cases of familial atrioventricular septal defect do not support this genetic mechanism, but suggest that there is a subgroup without trisomy 21 that has a single gene disorder.

Atrial natriuretic peptide as a marker for doxorubicin-induced cardiotoxic effects.

Doxorubicin is an effective antineoplastic agent, but it frequently causes dose-related cardiotoxic effects. Because the atrial natriuretic peptide (ANP) level is elevated in children with heart defects, the authors measured the ANP levels in children to determine whether ANP might serve as a simple diagnostic indicator of cardiotoxic effects. Sixteen patients, 5 to 19 years of age, who were being treated with doxorubicin (45 mg/m2 body surface area) for various malignancies had ANP levels measured in plasma. There was a group of six children, with a significant peak of plasma ANP (pANP) levels 3 weeks after the administration of the drug. Of these six patients, five had received high cumulative doses of doxorubicin (160 to 370 mg/m2), and two of them went into congestive heart failure without a previous decline in left ventricular ejection fraction, a standard technique for monitoring cardiac function during treatment with doxorubicin. The other ten patients had normal ANP levels throughout the study, and signs of cardiac dysfunction did not develop. None of the patients in the control group who had cancer and were not treated with doxorubicin and none of the healthy volunteers had elevated ANP levels. These preliminary results suggest that pANP may be useful as an early and sensitive indicator for doxorubicin-related myocardial damage.

Balloon dilatation for cardiac obstructive lesions in infants and children.

PBD has been used to relieve a wide variety of cardiac obstructive lesions in infancy and childhood. However, it has been most frequently used for semilunar valve stenosis, particularly PS. Results of pulmonic PBD are almost uniformly satisfactory for relief of typical PS, and the low rate of significant complications show that it is a safe procedure in practiced hands. It is now considered the treatment of choice for typical PS. Recently reported results of PBD for critical neonatal PS are also encouraging. New generations of balloon catheters better suited for neonatal balloon valvuloplasty will probably facilitate the procedure. In contrast, results for dysplastic valves are poor, suggesting that this condition is not amenable to PBD. Aortic stenosis also responds well to PBD in infancy and childhood when the valve is not dysplastic. The procedure in general is technically more difficult than pulmonary valvuloplasty, with a higher rate of complications, especially in neonates.

Cardiac decompensation following verapamil therapy in infants with supraventricular tachycardia.

Three infants with supraventricular tachycardia and congestive cardiac failure were given verapamil intravenously. In two of the infants, the rhythm was converted to sinus, but the third infant required direct current cardioversion. However, each infant demonstrated hemodynamic decompensation shortly after verapamil administration and required cardiopulmonary resuscitation. All three patients were stabilized and their tachycardia was controlled with digoxin. All three were doing well at the time of follow-up evaluation, and there was no evidence of structural heart disease. The risk of cardiac decompensation in infants with supraventricular tachycardia and congestive cardiac failure should be kept in mind prior to administration of verapamil. Alternative methods for conversion of supraventricular tachycardia should be considered.

Specificity of persistence of antibody to the streptococcal group A carbohydrate in rheumatic valvular heart disease.

The specificity of the persistence of antibody to the streptococcal group A carbohydrate for mitral valve disease induced by rheumatic fever was examined. Levels of the antibody were determined in serum samples of 30 patients with rheumatic mitral insufficiency, 30 patients with mitral valve prolapse, and an equal number of normal individuals and patients with congenital heart disease. Antistreptolysin titers and anti-deoxyribonuclease B titers were also assayed in all sera. There were no differences in the incidence of elevated antibody titers or in the geometric means of the antibody titers for the normal individuals, the patients with congenital heart disease, and the patients with mitral valve prolapse. In contrast, the frequency of elevated anti-streptococcal group A carbohydrate titers and the geometric means of these titers were significantly higher in the patients with rheumatic mitral valve disease than in patients with mitral valve prolapse. This confirms the specificity of the persistent elevation of anti-streptococcal group A carbohydrate to patients with mitral valve disease induced by rheumatic fever and also suggests that the persistence of this antibody in patients with rheumatic valvular disease is not a result of a functional abnormality of the mitral valve.

Right heart pigtail catheter for selective angiocardiography.

The use of a modified pigtail catheter for right heart angiocardiography provides a safe method of obtaining good quality contrast studies of right heart lesions in infants and children. The catheter is also useful in left ventriculography in complete atrioventricular canals or other complex cardiac lesions.

Cardiovascular manifestations in the Larsen syndrome.

The Larsen syndrome consists of a skeletal dysplasia with multiple joint dislocations and a characteristic facies. The basis of the abnormalities is felt to be a generalized mesenchymal disorder involving connective tissues. More than 80 cases have been reported in the literature with isolated reports of congenital cardiac septal defects and acquired abnormalities of the aorta and mitral valve. A case with marked aortic dilation and insufficiency as well as an aneurysm of the ductus arteriosus is presented. The aortic lesions are similar to those described in other connective tissue disorders, particularly the Marfan syndrome. Previous reports of ductal aneurysms have not revealed an association with connective tissue disorders, but have described a significant morbidity. In summary, patients with the Larsen syndrome are likely to have cardiac lesions similar to those classically associated with the Marfan syndrome; these patients deserve a careful investigation for cardiac anomalies. These aortic lesions may be as prognostically significant as cardiac lesions in the Marfan syndrome.

Interatrial groove tear: an unusual complication of balloon atrial septostomy.

The authors present an unusual complication of the balloon atrial septostomy procedure performed in a neonate with D-transposition of the great arteries. Cardiac tamponade developed shortly after the balloon atrial septostomy procedure and the infant was found to have a tear in the superior aspect of the left atrium, parallel to the interatrial groove. The tear was successfully sutured and may have been caused by the greater pull-back force needed if the catheter balloon is maximally distended for the first pull-back.

Hypertrophic cardiomyopathy in infants: clinical features and natural history.

The clinical and morphologic features of hypertrophic cardiomyopathy in 20 patients recognized as having cardiac disease in the first year of life are described. Fourteen of these 20 infants were initially suspected of having heart disease solely because a heart murmur was identified. However, the infants showed a variety of clinical findings, including signs of marked congestive heart failure (in the presence of non-dilated ventricular cavities and normal or increased left ventricular contractility) and substantial cardiac enlargement on chest radiograph. Other findings were markedly different from those usually present in older children and adults with hypertrophic cardiomyopathy (e.g., right ventricular hypertrophy on the ECG and cyanosis). Consequently, in 14 infants, the initial clinical diagnosis was congenital cardiac malformation other than hypertrophic cardiomyopathy. Twelve of the 14 infants who underwent left-heart catheterization showed substantial obstruction to left ventricular outflow (peak systolic pressure gradient greater than or equal to 35 mm Hg). However, unlike older patients with hypertrophic cardiomyopathy, infants with this condition commonly had marked obstruction to right ventricular outflow (35-106 mm Hg) (nine patients); in six patients, the magnitude of obstruction to right ventricular outflow was at least as great as that to left ventricular outflow. Asymmetric hypertrophy of the ventricular septum relative to the left ventricular free wall was present in the 16 patients who had echocardiographic or necropsy examination. Ventricular septal thickening was substantial in patients studied both before and after 6 months of age (mean 16 mm), indicating that in patients with hypertrophic cardiomyopathy, marked left ventricular hypertrophy may be present early in life and is probably congenital. The clinical course was variable in these patients, but the onset of marked congestive heart failure in the first year of life appeared to be an unfavorable prognostic sign; nine of the 11 infants with congestive heart failure died within the first year of life. In infants with hypertrophic cardiomyopathy, unlike older children and adults with this condition, sudden death was less common (two patients) than death due to progressive congestive heart failure.

The significance of the left atrial appendage in rheumatic heart disease.

The possible diagnostic value of an enlarged left atrial appendage (LAA) on the posterior-anterior or right anterior oblique chest film as a means of implicating a rheumatic etiology for mitral valve disease in children was investigated. Chest films were examined without prior knowledge of clinical or laboratory data, and the results were later correlated with this information in 113 children and adolescents. The clinical and laboratory data included application of the modified Jones criteria for the diagnosis of acute rheumatic fever, streptococcal antibody titers and clinical and cardiac catheterization findings. In children with mitral valve disease, our data suggest that as enlarged LAA, especially in the presence of pulmonary venous obstruction, is characteristic of rheumatic heart disease. This finding appears to be particularly useful, in conjunction with streptococcal antibody studies, in distinguishing rheumatic from nonrheumatic patients with mitral insufficiency.

Aneurysm of the subclavian artery: a complication of retrograde brachial artery catheterization.

A case of an aneurysm of an anomalous right subclavian artery following retrograde catheterization of the right brachial artery is described. This complication was not recognized until the patient presented with symptoms related to a superior mediastinal mass. After appropriate studies were performed operative intervention was successful in establishing a patent subclavian artery.

A simplified method for quantitating left-to-right shunts from arterial dilution curves.

This report presents a new, simple and reliable method of quantitating left-to-right shunts from arterial dilution surves. When indicatior (e,g., indocyanine green) is injected centrally (right venticle or pulmonary artery) and blood is withdrawn rapidly from either the aorta or other central systemic artery, in the presence of a left-to-right shunt to recorded indicator-dilution curve usually shows two discrete peaks: p-1 of the magnitude of the shunt expressed as percent of pulmonary blood flow, Experimental and clinical data demonstrate that this method is accurate in quantitating shunts from such curves.