Tetralogy of fallot with persistent fifth aortic arch: echocardiographic diagnosis.

Although persistent, fifth aortic arch (P5A) is an uncommon anomaly. Its incidence is unknown due largely to failure of recognition. Fundamental to its diagnosis is an adequate understanding of the various settings in which P5A may manifest.

Transcatheter occlusion of large pulmonary arteriovenous fistula.

We describe the compound transcatheter occlusion of a large and symptomatic pulmonary arteriovenous malformation in a 58-yr-old man. Pre- and postintervention clinical and laboratory data support the impression of an excellent outcome.

Significant pulmonary valve incompetence following oversize balloon pulmonary valveplasty in small infants: A long-term follow-up study.

Oversized dilatation balloons are recommended for relief of valvar pulmonic stenosis in infants and children during cardiac catheterization. Little information exists about the long-term outcome of this practice. Six of 107 consecutive patients undergoing balloon pulmonary valveplasty developed increasing pulmonary valve incompetence during follow-up periods of 0.

Vessel-sparing technique for coil occlusion of the very small patent ductus arteriosus.

A technique is described for coil occlusion of the small patent ductus arteriosus through a 4 French arterial catheter. The need for a 5 French sheath and catheter to stabilize the 3 French size delivery catheter system is obviated. The method is proposed as a way to minimize arterial vascular injury in the small patient undergoing transcatheter occlusion of the small ductus.

Ventricular arrhythmias in children with an apparently normal heart.

Ventricular ectopy occurs frequently in normal children. In the presence of a normal heart, these arrhythmias, including asymptomatic, nonsustained ventricular tachycardia, carry a benign prognosis and are not associated with sudden, unexpected death. However, complex ventricular arrhythmias frequently indicate the presence of underlying cardiac disease; patients with such arrhythmias must undergo an appropriately thorough evaluation before decisions regarding prognosis and the need for therapy can be made.

Great vein and right atrial thrombosis in critically ill infants and children with central venous lines.

We performed a retrospective review of echocardiographic data files of infants and children hospitalized in the Newborn and Pediatric Intensive Care Units. Echocardiograms were examined to detect the presence and evolution of great vein and right atrial thrombosis in patients with central venous lines. Thirty-seven patients were identified over a five-year period.

Rate-adaptive cardiac pacing in children using a minute ventilation biosensor.

Chronotropic integrity is required for a normal cardiac output response to exercise. We evaluated a rate-adaptive ventricular demand pacemaker (Telectronics, META-MV) which uses minute ventilation as the sensed physiological variable for adjusting pacing rate, in seven young patients with a mean age of 11.4 years.

Cellular electrophysiologic responses of isolated neonatal and adult cardiac fibers to d-sotalol.

The short-term cellular electrophysiologic actions of d-sotalol on isolated neonatal and adult canine ventricular myocardium and Purkinje fibers were evaluated using standard microelectrode techniques. d-Sotalol, 10(-6) to 10(-4)M, had no effects on action potential amplitude, maximal diastolic potential or action potential upstroke velocity (Vmax) in any neonatal or adult preparation. In five adult myocardial preparations, d-sotalol produced concentration-dependent increases in action potential duration at 50% (APD50) and 90% (APD90) repolarization and effective refractory period.

Electrophysiologic effects of desethylamiodarone, an active metabolite of amiodarone: comparison with amiodarone during chronic administration in rabbits.

During acute superfusion studies by means of the standard microelectrode technique, we previously showed that both amiodarone and its major metabolite, desethylamiodarone, had a modest effect on the lengthening of the action potential duration (APD) at high drug concentrations and produced a rate-dependent block of the sodium channel in cardiac muscle. In this study the comparative electrophysiologic effects of the two compounds in rabbits treated chronically with these compounds were determined with particular reference to repolarization and sinus node automaticity. The changes were correlated with those in serum and tissue drug levels and in thyroid hormone indices.

Medical management of three asymptomatic infants with severe valvar aortic stenosis.

We report on the clinical course and serial hemodynamic studies of three patients with severe valvar aortic stenosis diagnosed in the neonatal period. None of the children were symptomatic in the first year of life. In each case, a conservative initial management approach was adopted.

Amiodarone efficacy in a young population: relationship to serum amiodarone and desethylamiodarone levels.

Serum amiodarone and desethylamiodarone levels were measured in children and young adults receiving chronic amiodarone therapy. The study population consisted of 34 children and young adults with ventricular tachycardia (36%), atrial flutter (36%), and recurrent supraventricular tachycardia (27%). The mean age was 12.

Hemodynamic consequences of neonatal polycythemia.

The hemodynamic consequences of neonatal polycythemic hyperviscosity and the effects of partial exchange transfusion were evaluated in 13 infants. Mean (+/- SD) venous hematocrit was 72% +/- 2.5%.

Systemic oxygen transport in patients with congenital heart disease.

The physiology of oxygen delivery was studied in 118 stable patients from 3 months to 20 years old with congenital heart disease. During cardiac catheterization, oxygen consumption (VO2), arterial and venous blood gases and oxygen saturations (range 41% to 98%), hemoglobin concentration, diphosphoglycerate (2,3-DPG), and P50 levels were measured, and then cardiac output, systemic oxygen transport (SOT), arterial and venous oxygen contents, and the VO2/SOT ratio (fractional O2 extraction) were calculated. P50 averaged 31 mm Hg, compared with 27 mm Hg in 10 control children (p less than .

Effects of flecainide on the cellular electrophysiology of neonatal and adult cardiac fibers.

The acute cellular electrophysiologic actions of flecainide acetate on isolated neonatal and adult canine ventricular myocardium and Purkinje fibers were evaluated with standard microelectrode techniques. Flecainide, 0.1 to 10.

Long-term follow-up of bronchopulmonary dysplasia.

We observed 10 children with bronchopulmonary dysplasia, evaluated initially by cardiac catheterization (mean age 18 months), for an average of 4.4 years. Age at last evaluation averaged 5.

Communicating hydrocephalus: a reversible complication of the Mustard operation with serial hemodynamics and long-term follow-up.

Severe superior vena caval (SVC) obstruction following the Mustard operation resulted in substantially increased intracranial pressure in 3 patients. A pathophysiological mechanism is postulated to explain the cerebral edema in 1 and the communicating hydrocephalus in 2. Following surgical relief of the obstruction in the latter 2, there was a decrease in both the rate of head growth and the ventricular size.

Electrophysiologic effects of the levo- and dextrorotatory isomers of sotalol in isolated cardiac muscle and their in vivo pharmacokinetics.

Dl-sotalol is a specific beta-adrenergic blocking agent that markedly lengthens cardiac action potential duration. To determine whether d-sotalol, with little or no beta-blocking effect, also lengthens repolarization, standard microelectrode studies were used to determine the electrophysiologic properties of dl-sotalol and its stereoisomers in isolated rabbit and canine myocardial fibers. D- and l-sotalol produced concentration-dependent increases in action potential duration to 50% (APD50) and 90% (APD90) repolarization, respectively, and in the effective refractory period without changes in the maximal rate of rise of action potential.

Effects of amiodarone and its metabolite, desethylamiodarone, on the electrophysiologic properties of isolated cardiac muscle.

The electrophysiologic (EP) effects of chronically administered amiodarone (AM) is known, but the nature of its acute effects are unclear. Whether the delayed onset of AM action is due to its metabolite, desethylamiodarone (DAM), is also uncertain. By standard microelectrode techniques in isolated canine ventricular muscle (VM) and Purkinje fibers (PF) and in rabbit sinoatrial (SA) node and atrium, we therefore studied the comparative effects of AM and DAM, 10(-6) M (0.

Effects of hypoxia on the cellular electrical activity of adult and neonatal canine ventricular myocardium.

Standard microelectrode techniques were utilized to evaluate the effects of acute hypoxia on the cellular electrical activity of neonatal and adult ventricular myocardium. Control action potential parameters from adult and neonatal tissues were not significantly different. Thirty minutes of acute hypoxic superfusion significantly (p less than 0.