Victor Whitman

Dilatation of the ductus arteriosus by prostaglandin E1 in aortic arch abnormalities.

Infants with aortic arch interruption or juxtaductal coarctation of the aorta may depend on patency of the ductus arteriosus to provide adequate lower body perfusion. In many such infants the ductus arteriosus constricts after birth, resulting in severe heart failure, poor systemic perfusion and acidemia. We infused prostaglandin E1 (PGE1) at a rate of 0.05-0.1 Ag/kg/min into seven infants with aortic arch interruption and eight infants with coarctation. In one infant in each group the ductus arteriosus was already closed and did not reopen. In one infant with coarctation an adequate trial was not accomplished, and in another adequate pressure measurements were not obtained. Of the remaining 11, the ductus arteriosus was effectively dilated by PGE1 in 10 infants. This was evidenced by an increase in descending aortic blood pressures and a reduction in the pressure difference between the main pulmonary artery and descending aorta in six infants with aortic arch interruption and between ascending and descending aorta in four infants with coarctation. Lower body perfusion improved and left ventricular failure was improved. The infant who did not respond was 5 months old. There were no complications.

Indomethacin Disposition and Indomethacin-Induced Platelet Dysfunction in Premature Infants

Indomethacin failed to produce permanent ductal closure in any of four premature infants with patent ductus arteriosus to whom the drug was given. Indomethacin half-lives measured in two premature infants were 21 and 24 hours, respectively, much longer than in full-term newborns or adults. Platelet function, as measured by platelet aggregation, was grossly abnormal for two to four days after indomethacin administration, normal values returning only by the ninth and tenth days. Gastrointestinal bleeding and transient renal dysfunction occurred in one infant. Measurement of plasma indomethacin concentrations in sick, low-birthweight infants could help guide indomethacin dose and dosage interval, prevent drug accumulation, and reduce toxicity. Further studies of potential toxicity seem to be indicated before instituting widespread indomethacin administration for ductal closure in premature infants.

The development of pulmonary vascular obstructive disease after successful Mustard operation in early infancy.

SUMMARY Pulmonary vascular obstructive disease developed postoperatively in an infant with aortopulmonary transposition and intact ventricular septum who underwent a Mustard operation at 3 months of age. Preoperative catheterization had shown normal pulmonary artery pressures. Four months after surgery, catheterization showed pulmonary artery systolic pressure above the systemic level and a tortuous, attenuated pulmonary vascular tree visualized angiographically. Early corrective surgery may not preclude the development of pulmonary vascular obstructive disease in patients with aortopulmonary transposition.

Pulsed Doppler and two-dimensional echocardiographic findings in aortico-left ventricular tunnel

Two-dimensional echocardiography was used to make the anatomic diagnosis of aortico-left ventricular tunnel in a 1 day old infant. Pulsed Doppler echocardiography allowed directional flow to be determined within the tunnel. The findings were confirmed by cardiac catheterization and by direct visualization at the time of surgical repair. Aortic valve insufficiency was excluded before and after surgery using pulsed Doppler echocardiography. The anatomy and physiology of aortico-left ventricular tunnel can thus be documented using noninvasive techniques.

Digoxin therapy in low-birth-weight infants with patent ductus arteriosus

Digoxin therapy was evaluated retrospectively in a group of 30, and prospectively in a group of 16 low-birth-weight, premature infants with cardiorespiratory symptoms due to persistent patency of the ductus arteriosus. The response to decongestive therapy was equivocal. Digoxin levels in serum varied between 1.5 and 13 ng/ml. Digoxin half-life in serum exceeded three days in four patients. Fourteen of the combined group of 46 infants had signs of toxicity of digoxin. High dosage, inadvertent overadministration, and variable clearance of digoxin, as well as special characteristics of the patients studied, are postulated as explanations for the high incidence of toxicity. This study suggests that digoxin therapy in low-birth-weight, premature infants with patent ductus arteriosus is not without risk.

Ductus arteriosus aneurysm presenting as pulmonary artery obstruction: diagnosis and management

The occurrence of pulmonary artery obstruction in an 8 day old infant as a complication of an aneurysm of a nonpatent ductus arteriosus is reported, together with the echocardiographic and angiographic findings. To relieve the obstruction, the aneurysm and an intrapulmonary thrombus were successfully removed with the use of cardiopulmonary bypass when the infant was 3 months old.

Metabolic and functional consequences of chronic alcoholism on the rat heart.

Abstract Conflicting data concerning cardiac function and energy metabolism in chronic alcoholism have been reported. Previous studies have shown preferential metabolism of ketone bodies and acetate, a primary metabolite of ethanol, leading to diminished myocardial high energy phosphate stores. We evaluated the following parameters in chronically, severely alcoholic rats: cardiac function utilizing working heart preparations with variable afterload; high energy phosphate stores; and mitochondrial respiratory activity. At low work load no differences existed in hemodynamic measurements between hearts from alcoholic and control animals; however, immediately after the imposition of an increased afterload, hearts from alcoholic animals exhibited a subnormal increment in pressure development. This decrement normalized during the following 30 min of perfusion. ATP and creatinine phosphate levels in hearts from alcoholic animals which were excised and immediately frozen and in those which had been perfused as working heart preparations for 120 min were not different from those found in controls. Studies on mitochondrial respiration revealed a diminished activity of the myocardium from alcoholic rats to utilize glutamate as a substrate; however, the utilization of other substrates was unaffected by alcohol consumption. It is concluded that in chronically alcoholic rats minor changes occur in cardiac function; the heart maintains normal high energy stores; however, alternative substrates are utilized for the production of energy.

Effects of chronic ethanol consumption on the myocardial hypertrophic response to a pressure overload in the rat.

Abstract In view of the intrinsic defect in myocardial protein synthesis in the presence of acetaldehyde, the primary metabolite of ethanol, the effects of prolonged ethanol consumption on the hypertrophic response of the rat heart were studied. Changes in heart weight, myocardial protein and RNA content in response to banding of the ascending aorta were determined. Heart weight and heart to body weight ratios were reduced in non-banded ethanol diet animals when compared to nonbanded control diet rats. The extent of myocardial hypertrophy and the increment in RNA content resulting from banding were similar in both ethanol and control diet animals. These data indicate that although basal myocardial protein synthesis may be diminished in the alcoholic animal, the ability to respond in a compensatory manner to the stress imposed by aortic banding is retained.

Modified Shumacker repair of transposition of the great arteries.

Seven infants weighing from 6.4 to 10.3 kg underwent correction of transposition of the great arteries by the venous transposition operation as described by Shumacker. In this operation, a new atrial septum is constructed using a bipedicled right atrial flap, and the lateral atrial wall is constructed using a viable pericardial flap. Three of the patients had an associated ventricular septal defect. Six of the seven patients survived and have had an excellent clinical result. Although atrial arrhythmias were common in the early postoperative period, all patients are now in sinus rhythm. Two patients have had postoperative cardiac catheterization and cineangiography, which showed excellent hemodynamic results. The modified Shumacker operation preserves two of the three internodal pathways, provides a compliant, viable atrial septum, and permits fabrication of a generous-size physiological left atrium. This appears to offer advantages not present in the Mustard procedure.

Anomalous Mitral Arcade: Echocardiographic and Angiographic Recognition

SummaryA patient with sudden onset of hemiplegia was noted to have an anomalous mitral arcade at cardiac surgery. Echocardiographic and angiographic data are correlated with the anatomic findings. The clinical significance of this anomaly is discussed.