Pediatric autoimmune cardiovascular disease.

Pediatric autoimmune cardiovascular disease can cause serious, sometimes life threatening sequelae on the pediatric population. Valvular, myocardial, and pericardial involvement causing morbidity and mortality can occur in association to rheumatic heart disease, systemic lupus erythematosus, and juvenile rheumatoid arthritis. Serious and potentially life threatening coronary artery involvement can occur in patients with childhood polyarteritis nodosa, Takayasu arteritis, and Kawasaki disease.

Taussig-Bing anomaly: arterial switch versus Kawashima intraventricular repair.

BACKGROUND: Current corrective surgical approaches for the Taussig-Bing heart include arterial switch with ventricular septal defect (VSD) closure and intraventricular repair as described by Kawashima. METHODS: Between 1983 and 1994, 20 children underwent intracardiac repair of Taussig-Bing anomaly. Mean age at operation was 17 months (range, 1 week to 9 years). Prior palliation included pulmonary artery band (15) with coarctation repair (8) and atrial septectomy (1). Arterial switch with VSD closure was performed in 16 patients, 10 with anteroposterior great arteries. Kawashima repair was performed in 4 patients, all with side-by-side great arteries. RESULTS: After arterial switch, there was one operative death (6.2%) due to myocardial ischemia and three late deaths (18.7%) due to pulmonary hypertension, gastrointestinal bleeding, and acute lymphocytic leukemia. In the Kawashima repair group there have been no deaths. After arterial switch, 9 patients underwent 11 reoperations for residual coarctation (3), residual pulmonary artery stenosis (2), aortic valve replacement, aortic valvuloplasty, unrecognized VSD, mitral valvuloplasty, mediastinitis, and pacemaker insertion. After Kawashima repair, 1 patient underwent reoperation for baffle stenosis and 1 for an unrecognized VSD. CONCLUSIONS: For children with Taussig-Bing anomaly, the Kawashima intraventricular repair (for side-by-side great arteries) preserves the native aortic valve and avoids coronary dissection. The arterial switch operation with VSD closure can be applied without ventriculotomy to all great artery relationships and allows neonatal repair with or without concomitant coarctation repair. Both techniques yield excellent early and intermediate-term results despite the high rates of prerepair palliation and postrepair reoperation for both groups.

Transtelephonic echocardiography: successful use in a tertiary pediatric referral center.

Recent advances in computers and telecommunications have made transtelephonic echocardiography practical. Our institution is developing a network of transmissional echocardiographic sites at several hospitals in our referral region. We reviewed our initial experience to determine whether transmissional echocardiographic studies (1) gave an appropriate diagnostic impression compared with subsequent videotape review and (2) led to appropriate clinical management (i.e., transfer to a tertiary center or continuation of local care and follow-up). From Aug. 1, 1991, to May 31, 1992, we evaluated 47 transmissional studies (diagnoses: 24 normal, 8 patent ductus arteriosus, 6 ventricular septal defect, 2 pulmonary stenosis, 1 ventricular septal defect with interrupted aortic arch, and 6 miscellaneous). Of 47 studies, 39 (83%) were thought to give accurate diagnostic impressions compared with videotape review. Most inaccuracies were due to the selection and transmission of inconclusive information in an otherwise accurate diagnostic study. Only 1 (2%) of 47 studies resulted in an inappropriate clinical decision; a patient's transfer for treatment of a potent ductus arteriosus was delayed 1 day because of an inconclusive transmissional study. We conclude that transmissional echocardiography is useful in the management of pediatric patients with suspected heart disease in a regional referral setting.

Competitive antagonism of glutamate receptor channels by substituted benzazepines in cultured cortical neurons.

Whole-cell recordings from rat cortical neurons in dissociated cell culture were used to study the antagonism of glutamate receptors by several lipophilic benzazepine analogues of 2,5-dihydro-2,5-dioxo-3-hydroxy-1H-benzazepine (DDHB). DDHB and three substituted derivatives, 4-bromo-, 7-methyl-, and 8-methyl-DDHB, inhibited the activation of N-methyl-D-aspartate (NMDA) receptors at both the NMDA recognition site and the glycine allosteric site. In addition, all four compounds blocked the activation of non-NMDA receptors by kainate and L-glutamate. Antagonism by the four benzazepines was equivalent at holding potentials from -80 mV to +50 mV. Both the onset of and recovery from block of the agonist-gated currents were complete within seconds. Antagonist affinity was calculated from the displacement of steady state concentration-response curves for kainate, L-glutamate, glycine, and NMDA, based on the Gaddum-Schild relationship (dose ratio = 1 + [antagonist]/KB). The most potent blocker, 8-Me-DDHB, had an apparent dissociation constant (KB) of 470 nM at the glycine allosteric site and 27 microM at the NMDA recognition site. The apparent dissociation constant of 8-Me-DDHB for non-NMDA receptors was 6.4 microM when kainate was the agonist and 9.6 microM when L-glutamate was the agonist. Unsubstituted DDHB showed slightly higher affinity for the NMDA recognition site (KB = 16 microM) but was less potent than 8-Me-DDHB at the glycine allosteric site and at non-NMDA receptors (KB = 3 and 65 microM, respectively). At all three sites, the inhibitory actions of these benzazepine derivatives were consistent with a simple competitive mechanism of antagonism. In addition, the antagonist potency of the parent compound, DDHB, against kainate, NMDA, and glycine was equal to or greater than that of other bicyclic antagonists, including kynurenic acid, indole-2-carboxylic acid, and quinoxaline-2,3-dione. Substituted benzazepines represent a new class of glutamate receptor antagonists that show competitive action, significant potency at multiple sites, and a high degree of lipophilicity.

Echocardiography for evaluating anatomic repair of transposition of the great arteries.

Fifteen survivors of a single-stage anatomic correction of complete transposition of the great arteries performed at a mean age of 1 month were studied by cross-sectional echocardiography, conventional Doppler echocardiography, Doppler color flow mapping, and catheterization at mean of 10 months after surgery. Small aortic regurgitant jets were documented by angiography and Doppler color flow mapping in seven patients. A trivial supravalvular pulmonary gradient was present in seven patients and a mild to moderate gradient in three. Pulmonary artery flow velocities correlated well with those measured at cardiac catheterization (r = 0.96, standard error of the estimate = 2.6 mm Hg). The present study suggests that combined cross-sectional echocardiography, conventional Doppler echocardiography, and Doppler color flow mapping can be used in the follow-up of patients who have had anatomic repair of transposition of the great arteries, reducing the need for repeated postoperative cardiac catheterizations.

Two-dimensional echocardiographic assessment of intracardiac masses in infants and children.

We studied six infants and children with intracardiac masses of different causes. The diagnosis was made noninvasively using two-dimensional echocardiography in all six patients. In five patients, surgical excision of the mass was undertaken with good results. Two-dimensional echocardiography is an excellent noninvasive diagnostic tool that allows the clinician to determine the size and location of intracardiac masses in infants and children.

Surgical approach to atrial septal defect in the female. Right thoracotomy versus sternotomy.

Repair of atrial septal defect (ASD) remains a high-benefit, low-risk procedure due to technologic improvements. From July 1981 to December 1986, 35 females (age, 7 months to 28 years) had repair of ASD; 20 by right thoracotomy and aortic cannulation (group 1) and fifteen by median sternotomy (group 2). In general, right thoracotomy was applied to patients with secundum ASD two years or older and without associated lesions, while median sternotomy was applied to patients with ostium primum lesions and/or associated lesions. Patients or their families perceived the cosmetic results superior to the right thoracotomy approach over the median sternotomy. We feel that a right thoracotomy and aortic cannulation is effective in females (2 years and older) with secundum ASD for a superior cosmetic result over median sternotomy. However, females with ostium primum and/or associated lesions should undergo median sternotomy for better cardiac access and safety.

Surgical repair of atypical coarctation of the abdominal aorta in an infant.

A seven-week-old infant with multiple areas of coarctation of the abdominal aorta and renal artery pathology underwent staged surgical repair of his malformations in our medical center. The clinical and routine echocardiographic evaluations suggested the diagnosis of atypical coarctation of the aorta. The exact anatomical characteristics of his vascular malformations were established by repeated angiocardiographic studies, which should be performed in any patient in which the diagnosis of atypical coarctation of the aorta is suspected.

Neonatal refractory supraventricular tachycardia: successful treatment with amiodarone.

A 3-week-old neonate with supraventricular tachycardia unresponsive to traditional therapy was treated successfully with amiodarone. An electrophysiologic study suggested the presence of a concealed left-sided accessory atrioventricular pathway. Because of its significant side effects, amiodarone should be used only as a last resort in the treatment of neonatal supraventricular tachycardia.

Modified aortoseptoplasty for anular abscess and erosion of the membranous septum.

Surgery for bacterial endocarditis may require extensive debridement and appropriate reconstruction for optimal results. Excision of the aortic valve and eroded membranous septum due to pneumococcal endocarditis with modified aortoseptoplasty was successfully accomplished in a six-year-old child.

Left atrial-left ventricular bypass for congenital mitral stenosis.

The case of a patient with congenital mitral stenosis successfully treated by insertion of a left atrial-left ventricular valved conduit is presented. After insertion of the conduit, pulmonary artery pressure was normal, persistent pulmonary edema and ascites disappeared, and the child's rate of growth and level of activities returned to normal.

Noninvasive evaluation of cardiovascular effects of preoperative sedation in children.

The cardiovascular effects of two premedication regimes used in paediatric anaesthesia were studied. Eleven patients received rectal methohexitone (22 mg - kg) and 11 patients received intramuscular Innovar (0.03 ml - kg). The effect of these drugs on ventricular function was evaluated by measuring the shortening of the left ventricular minor dimension by echocardiography. No significant changes in this dimension, blood pressure, heart rate or respiratory rate were demonstrated with either drug. Both rectal methohexitone and intramuscular Innovar were shown to have minimal cardiovascular effects when used as preoperative sedation in paediatric patients. Echocardiography proved to be a valuable technique for the noninvasive evaluation of drug effects on myocardial contractility in children.

Echocardiographic evidence of left ventricular tumor in a neonate.

We present the case of a ten-hour-old infant with clinical findings suggestive of hypoplastic left-heart syndrome. A diagnosis of left ventricular tumor was made by echocardiographic examination. This diagnosis was confirmed at autopsy, when a large rhabdomyoma was found in the interventricular septum, obliterating the major portion of the left ventricular cavity. The echocardiographic findings are discussed.

Echocardiographic estimation of a left-to-right shunt in isolated ventricular septal defects.

35 infants and children with isolated ventricular septal defects (VSDs) had echocardiographic examination within 24 h of cardiac catheterization. Left atrial to aortic root (LA : Ao) ratio, left atrial internal dimension/meter square body surface area (LAID/m2) and left ventricular internal dimension in diastole/meter square body surface area (LVIDd/m2) were compared with the cardiac catheterization determined pulmonary-to-systemic flow (Qp : Qs) ratio. 35 children with normal cardiovascular findings served as controls. The LA : Ao ratio in the VSD group (1.38 +/- 0.13) was significantly higher than in the control group (1.01 +/- 0.05) (P less than 0.01). Similarly the LAID/m2 and LVIDd/m2 were significantly higher in the VSD group than in the control group (P less than 0.01). Additionally, echographic dimensions were increased in proportion to the elevation of Qp : Qs (r = 0.71--0.73). LA : Ao ratios higher than 1.4 : 1 were generally associated with Qp : Qs ratios greater than 2 : 1. All patients with Qp : Qs greater than 2 : 1 had LA : Ao ratios of 1.4 or higher. This study suggested that echocardiography is a useful noninvasive technique in estimating the Qp : Qs in patients with isolated VSDs, and may serve as an additional clinical parameter in the assessment of patients with VSDs.

Exercise electrocardiography in the evaluation of cardiac dysrhythmias in children.

Exercise electrocardiography is a useful means to evaluate dysrhythmias in children and young adults. Exercise may suppress a dysrhythmia present at rest and thus suggest a relatively benign problem. It may provoke a latent dysrhythmia which is absent at rest but suggested by a history of exercise intolerance or palpitation with exertion. Exercise may also modify a dysrhythmia. Maximum exercise testing has been used to evaluate each of these situations in children. The results of testing will be presented. Since no dysrhythmias were provoked in 170 healthy children, we think that any dysrhythmia initiated by exercise in the young should be considered abnormal.

Echocardiography in infants and children.

Echocardiography is a well established, non-invasive diagnostic technique that has assumed a prominent place in the armamentarium of the pediatric cardiologist. The principles and techniques of echocardiography are explained. In addition, the measurements and interpretation are described, as well as the deductive approach that leads to a specific diagnosis. The purpose of this discussion is to provide the pediatrician with an understanding of the appropriate application, value, and limitation of the echocardiogram.