Right ventricular volume in congenital heart disease.

With use of the Frank lead system, still loop and timed vectorcardiograms were recorded in more than 5,000 patients subjected to complete right and left heart catheterization and selective coronary cineangiography. Data so obtained demonstrated clinical superiority of the vectorcardiogram over the standard 12 lead scalar electrocardiogram. Specific advantages of the vectorcardiogram include (1) recognition of undetected atrial and ventricular hypertrophy, (2) greater sensitivity in identification of myocardial infarction, and (3) superior capability for diagnosis of multiple infarctions in the presence of fascicular and bundle branch blocks. The timed biplane vectorcardiogram is as useful as any number of simultaneously recorded electrocardiographic leads for the analysis of complex arrhythmias and beat to beat changes in intraventricular conduction. Since the validity and usefulness of this technique have been established, it should become part of the routine noninvasive evaluation of patients with cardiovascular disorders.

Postmortem digoxin tissue concentration and organ content in infancy and childhood.

The concentration of digoxin in tissues and the content of the drug in various organs are reported in 36 infants and children. Sixteen received the drug on a short-term basis and 20 on a long-term basis. The drug was given intravenously to 12, orally to 17, and by intramuscular injection to 7. The study was conducted to determine distribution of digoxin in infants and children and to examine the forensic implications related to digoxin overdosage. Upper therapeutic concentration thresholds for digoxin were established in various tissues. These are different for preterm and full-term neonates than for older children and adults; for example, adult and neonatal values for postmortem blood specimens are 8 and 15 ng/ml, and for ventricular myocardium are 250 and 450 ng/g, respectively. The chronically digitalized premature infant retains in most tissues a considerably larger fraction of digoxin than more mature infants and children. This is in accord with previously demonstrated lower renal digoxin levels in premature infants attributed to their reduced ability to excrete this drug.

Quantitative angiographic and morphologic aspects of aortic valve atresia.

Quantitative angiographic measurements were performed in 15 infants aged 1 to 35 days who had aortic valve atresia with intact ventricular septum and hypoplastic left ventricle. Thirteen infants had similar measurements performed at autopsy. The latter measurements were smaller than those found at angiography (because of shrinkage), but their relationship was predictable. Angiographic right ventricular (RV) volumes were 2 and 4 times normal in diastole and systole, respectively. The RV volume measured at autopsy was greater than 3 times normal. Mean RV ejection fraction was 0.40; it was below normal in 10 infants. Maximal right atrial volume was greater than 2 times normal, and mean left atrial maximal volume was two-thirds normal. The relation between circumferences of the aortic arch and ascending and descending aorta was similar at angiography and autopsy.

Congenital interruption of the inferior vena cava.

In the usual form of interruption of the inferior vena cava (IVC), the post-renal IVC continues as the azygos and hemiazygos vein. We report a patient with complete interruption of the IVC in whom no direct continuity existed between the IVC and the azygos system. Connection between these two systems was via the vertebral plexus and ascending lumbar veins. Associated venous malformations included bilateral azygos veins and anomalous connection of pulmonary and hepatic veins.

Anomalous left coronary artery in the infant: recovery of ventricular function following early direct aortic implantation.

A successful direct aortic implantation of an anomalous left coronary artery (ALCA) in an infant is reported. Detailed evaluation of postoperative ventricular function, including repeat cardiac catheterization and serial echocardiography, demonstrated progressive enhancement of ventricular contractility and function. Postoperative angiography confirmed vascular patency. These data support the concept that the ALCA should be corrected by direct aortic implantation early in infancy rather than by expectant treatment or graft interposition.

Infarct of the myocardium with aneurysm in a 13-year-old girl.

We present the case of a girl with an infarct and an aneurysm of the left ventricle after viral disease at the age of six years. She died suddenly at 13 years of age. Autopsy findings revealed occlusion of the anterior descending and narrowing of the right coronary artery. The possible relationship of virus disease to the vascular disease is discussed.

Interruption of patent ductus arteriosus in premature infants with respiratory distress syndrome.

In infants with respiratory distress syndrome (RDS) hypoxemia inhibits closure of the patent ductus arteriosus (PDA), resulting in increased pulmonary blood flow with subsequent increased hypoxemia. In an attempt to interrupt this cycle 42 consecutive premature infants with RDS and PDA, weighing between 550 and 2,000 gm (average, 1,383 gm) and with an average gestational age of 31 weeks, were arbitrarily treated either medically (13 patients) or by interruption of the PDA (20 patients). Eleven patients who were initially treated medically could not be weaned from the respirator and later underwent operation. There were no operative or anesthetic deaths; late survival was 65% (20 patients). The last 31 patients were randomly divided into operative and nonoperative groups. Preliminary results revealed no significant differences in late survival between the two groups. Since the operative risk is minimal, further investigative efforts are indicated to settle this issue.

Interrupted aortic arch operation in the first week of life: hemodynamic and angiographic evaluation one year later.

Operation for interrupted aortic arch (IAA) was successful in 2 infants during the first week of life. Both had postoperative hemodynamic and angiographic evaluation at one year of age. The first infant had a type A IAA, and prostaglandins were infused to prevent ductal closure prior to the insertion of a graft between the two ends of the interrupted aorta. The second infant had a palliative operation for type B IAA (pulmonary artery banding and graft from main pulmonary artery to descending aorta). These patients represent the ninth and tenth successful operations for IAA in this age group and are reported with long-term reevaluation.

Digitalis, digitalis antibodies, digitalis-like immunoreactive substances, and sodium homeostasis: a review.

Most pharmacokinetic and biologic attributes of digitalis are age dependent. They are determined in great measure by the chemical structure of the specific cardiac glycoside being used. These effects differ in the intact normal circulation and in heart failure because of the altered autonomic nervous system and hormonal control that exist in the latter. Digitalis is effective only in the presence of myocardial dysfunction, but in a clinical setting, cardiac performance may be difficult to gauge; improved tools are needed for this purpose. The dosages of digoxin recommended for infants and children have been steadily reduced in the past decade, and there is no good evidence that more favorable risk-to-benefit ratios are achieved when higher doses are used or when higher plasma concentrations are sought. Massive digitalis toxicity is a serious, often fatal, complication in young infants, especially when the drug is given parenterally; it may be difficult to diagnose early. The only reliable deterrent for this complication is the adoption of careful safety standards whenever the drug is employed. Experience with digoxin antibodies is still scarce in children, especially in infancy, but their use generally has been associated with a favorable outcome. Endogenous substances that interfere with the digoxin radioimmunoassay (DLIS) occasionally yield clinically relevant, erroneously high, plasma digoxin concentration readings in neonates. An interesting hypothesis currently being investigated is the physiologic and pathologic role of these compounds in sodium hemostasis; they may be part of a putative endogenous NaK-ATP-ase inhibitor involved in the pathogenesis of hypertension and renal diseases.

Tissue concentrations at autopsy in infants and children receiving therapeutic digoxin.

Therapeutic tissue concentrations of digoxin have been reported for relatively small numbers of infants and children. In forensic medicine, knowledge of these concentration ranges is important for confirming or excluding digoxin overdosage in different age groups. In addition to age and weight, other factors such as dosage, duration of treatment, route of administration, sampling site, time of last dose, and death-autopsy interval may influence tissue concentrations. In this paper we report on tissue concentrations in 36 infants and children who received therapeutic digoxin before death.