Translocation (3;12) (p21-pter; q24.1-qter) and phenylketonuria.

Cytogenetic karyotyping in mental retardation associated with physical dysmorphism has been regarded as the primary key for the classification of syndromes and other genetic disorders for the predisposition of neoplasia and other fatal diseases. Giemsa-banding of metaphase chromosomes in lymphocytes is a traditional and routine process for the identification of the chromosomal counterpart which can provide a clue for molecular investigation in the subject. An 8-year-old girl showed a diploid karyotype 46, XX, t(3;12) (p21-pter, q24.1-qter) in peripheral blood lymphocyte culture. Biochemical examination of urine labelled her as a case of phenylketonuria. The maternal karyotyping was similar and confirmed the maternal transmission of the translocation.

Pericentric inversion in human chromosome 8 and spherocytosis.

A cytogenetic study of a patient revealed a pericentric inversion in chromosome 8, and spherocytes in 10% of cells, in a routine blood smear. The critical portion which affected the expression of spherocytosis appeared to be localized at 8p22-8q21. The mother's karyotyping showed the transmission of the inversion to the child.

Natural history of isolated ventricular septal defect in the first five years of life.

BACKGROUND: Isolated ventricular septal defect (VSD) is the most common congenital heart defect. Incidence, prevalence, and clinical outcomes of VSD have been reported to vary significantly in different geographic areas. Spontaneous closure of VSD, in children, by various methods has been described. HYPOTHESIS: This prospective study was undertaken to evaluate natural history of patients with VSD in the first five years of life in the Northeast Tennessee and Southwest Virginia region. METHODS: Between December 1, 1998 and October 31, 1990, 124 infants were diagnosed clinically with isolated VSD. VSDs were classified as muscular, perimembranous, malalignment, or subpulmonic types by 2-dimensional echocardiogram with color flow mapping. Cardiac catheterization and angiocardiography were performed in 14 patients when clinically indicated. These patients were followed for at least five years. RESULTS: Overall spontaneous closure of VSD was 34% at one year and 67% at five years. Twenty-five percent of perimembranous and 4% of muscular VSDs required surgery by five years. The spontaneous closure rate of muscular VSD was twice that of the perimembranous type, though the relative distribution of both types was almost equal. Overall, 22% of children with VSD need follow-up after the fifth year of life. CONCLUSION: The overall clinical outcome of muscular VSD was consistently better than that of the perimembranous type, though 17% of muscular VSDs, irrespective of size, were open at 5 years of age and needed long-term follow-up.

An unusual peripheral vascular response to dopamine in a neonate.

We report a case of a neonate who developed hypotension immediately after birth, and needed dopamine infusion to sustain his blood pressure and tissue perfusion. He developed cyanosis of his extremity immediately after dopamine was started via peripheral line and improved spontaneously after dopamine was stopped. This happened repeatedly at various sites and at lower concentrations of dopamine. Subsequently, dopamine was replaced by dobutamine and the patient did well. We conclude that some neonates can show heightened alpha-adrenergic response to dopamine and this can lead to ischemic vascular events. Dopamine infusion in neonates should be started at a low-dose via central line.

Petit mal seizure in a child with Marfan's syndrome.

We report a case of a 17-year-old white girl with Marfan's syndrome and generalized absence-type seizures since 11 years of age. A video EEG recording for six hours demonstrated 52 episodes of clinical generalized absence-type seizures and three-per-second spike and wave epileptiform discharges, characteristic of petit mal epilepsy. Sodium valproate therapy was successful in controlling her seizures. In this article, we review various possible causes of epilepsy in patients with Marfan's syndrome.

Mediastinal bronchogenic cyst: diagnosis and follow-up.

A 5-year-old girl with an asymptomatic posterior mediastinal cyst from birth was followed with repeated echocardiograms. The cyst developed communication with the bronchus spontaneously around 8 months of age without clinical symptoms. This was detected from the sudden disappearance of the mass on echocardiogram, and an unusual air-pocket on chest roentgenogram. Computed tomography (CT) of the chest confirmed the diagnosis of communicating bronchogenic cyst (BC). She was treated successfully with complete surgical excision of the cyst and closure of the defect in the bronchus. We emphasize that surgery is indicated in all mediastinal BCs because of potential complications.

Natural history of asymptomatic valvar pulmonary stenosis diagnosed in infancy.

BACKGROUND AND HYPOTHESIS: Valvar pulmonary stenosis is a common congenital heart defect. Progression of stenosis over time, even when mild initially, has been shown by serial cardiac catheterization studies in children and adults. We studied the natural history of asymptomatic valvar pulmonary stenosis diagnosed in infancy with two-dimensional echocardiography and Doppler method. METHODS: Between November 1986 and March 1993, 51 infants in the Northeast Tennessee and Southwest Virginia region were clinically diagnosed to have isolated valvar pulmonary stenosis. In 40 patients, the diagnosis was confirmed by two-dimensional echocardiogram/Doppler and color-flow mapping study at the time of presentation, and only their course is reported. Of 40 infants, six asymptomatic infants (15%) showed rapid progression of pulmonary stenosis over a relatively short period of time. Within the first 6 months of life, three of the six infants showed worsening of the stenosis needing intervention (one had surgical valvectomy and the others had percutaneous balloon valvuloplasty). The three other infants showed a more gradual increase of pulmonary stenosis over the first 2 years of life. RESULTS: Pulmonary stenosis even when mild can worsen in infancy, and it is not possible to predict which patients will follow this course. In our group of asymptomatic infants with initial mild pulmonary stenosis, 15% developed significant stenosis that needed intervention. CONCLUSION: We recommend frequent follow-up of asymptomatic infants with mild pulmonary stenosis during the first 2 years of life to detect rapid progression that may need intervention.

Progressive congenital valvar aortic stenosis during infancy: five cases.

We report our experience with asymptomatic valvar aortic stenosis diagnosed during infancy. During the period between November 1, 1986 and October 31, 1992 a total of 13 infants were diagnosed with asymptomatic aortic stenosis, 5 of whom showed rapid progression over the first 2 years of life. Two of these asymptomatic infants had severe aortic stenosis by 2 months of age, requiring intervention. We agree that aortic stenosis is a progressive lesion even in mild cases, but we emphasize the need for close clinical and echocardiographic follow-up of these asymptomatic children during infancy to prevent congestive heart failure and sudden death.

Characteristics and management of chaotic atrial tachycardia of infancy.

Chaotic atrial tachycardia was observed in 7 infants without underlying structural heart disease. Clinical presentation and approach to management are discussed, with particular attention to the use of propafenone for this uncommon pediatric arrhythmia.

Experience with moricizine HCl in children with supraventricular tachycardia.

Eight children, age between 4.5 and 19 years were treated with moricizine for supraventricular tachycardia during the last 3 years. The tachycardia was documented by surface electrocardiogram (ECG), and/or by ambulatory ECG in all the children and the mechanism of tachycardia was determined by previously published surface ECG and electrophysiologic criteria in all but one child. Of the eight children, three had atrial ectopic tachycardia, three had automatic junctional ectopic tachycardia, one had atrioventricular (AV) nodal reentry tachycardia and one had atrial reentry. All the children except one had failed trial of two or more antiarrhythmic drugs prior to moricizine therapy. The duration of moricizine therapy ranged from 4 days to 25 months. In three of the eight children (patients 3, 5 and 7), who presented with AV nodal reentrant tachycardia, automatic junctional ectopic tachycardia and atrial ectopic tachycardia, respectively, moricizine therapy was effective in restoring sinus rhythm and controlling the clinical tachycardia. Only one child (patient 1) developed proarrhythmia, an episode of fast, narrow-QRS supraventricular tachycardia lasting for 30 s, on the third day of therapy. This was subsequently confirmed by electrophysiologic study to be AV nodal reentrant tachycardia. The other side effects noted were non-cardiac, not dose-dependant and did not require dis-continuation of therapy. Based on our small series and those of others, moricizine, a newer class I anti-arrhythmic agent, has a limited but useful role in the management of recalcitrant type of supraventricular tachycardia, such as ectopic atrial and junctional tachycardia in children.

Long-term efficacy and safety of atenolol for supraventricular tachycardia in children.

Propranolol, a first-generation nonselective beta-adrenoceptor blocking agent, is commonly used to treat pediatric arrhythmias. Atenolol, relatively long-acting, cardioselective beta-adrenoceptor blocking agent, has been successfully used in adults with supraventricular tachycardia (SVT). There is only one report on the use of atenolol in children with SVT; and our report is on the first long-term prospective study to evaluate the use of atenolol in children. A group of 22 children < 18 years of age with clinical SVT were enrolled in the study. The tachycardia was documented on electrocardiograms in each case and was confirmed by electrophysiologic studies in some. Once-a-day oral atenolol was started as a monotherapy. Of the 22 children with various types of SVT, 13 (59%) were well controlled on long-term oral atenolol therapy. The effective dose of atenolol ranged between 0.3 and 1.3 mg/kg/day (median effective dose 0.7 mg/kg/day). Five children had some adverse effects. However, none in the successful group of 13 patients required drug discontinuation because of such effects. Once-a-day oral atenolol as a monotherapy is effective and relatively safe for long-term management of SVT during childhood. It is an attractive alternative beta-adrenoceptor blocking agent for the management of pediatric arrhythmias.

Pharmacokinetics of moricizine in young patients.

Moricizine is a novel phenothiazine antiarrhythmic agent that depresses the activity of ectopic foci, has a low incidence of adverse effects relative to other agents, and is useful in treating pediatric atrial ectopic tachycardia. A study was conducted to determine the pharmacokinetics of moricizine in children after oral administration. Moricizine was isolated from frozen serum obtained from four male patients (ages 7, 8, 9, and 18 years) receiving the drug for supraventricular tachycardia and analyzed by high-performance liquid chromatography with ultraviolet detection according to an established protocol. Peak serum levels were between 400 and 2000 ng/mL. Elimination of moricizine did not follow simple single-compartment pharmacokinetics. In three patients we observed an increase or slower decline in blood level occurring after 4 hours. Because of the paroxysmal nature of the tachycardias, decreases in patient heart rate could not be correlated with moricizine blood level. These results suggest that the pediatric pharmacokinetics of moricizine excretion are complex and may differ from those seen in adults.

Familial symptomatic sinus bradycardia: autosomal dominant inheritance.

Symptomatic sinus bradycardia, due to either sick sinus syndrome or vagotonia, can be familial, affecting several members of a family. We report an 18-year-old male patient with palpitations and limited exercise capacity who was noted to have severe sinus bradycardia. His resting heart rate was 40/min, with normal PR and corrected QT intervals, and sinus pauses up to 6 seconds during sleep. Exercise treadmill test and pharmacologic autonomic blockade during electrophysiologic studies abolished the bradycardia, suggestive of vagotonia rather than intrinsic sinus node dysfunction. This patient's father and a female cousin had a similar clinical history but associated with syncope and severe sinus bradycardia. The mode of transmission appeared to be autosomal dominant. All three have permanent demand pacemakers implanted and are asymptomatic.