Spontaneous closure of ventricular septal defect.

One thousand sixty-six patients with ventricular septal defect were followed. Spontaneous closure occurred in 71%, whereas 5% needed operative closure and 2.3% died.

Status of patients 5 or more years after correction of coarctation of the aorta over age 1 year.

In this retrospective study, we reviewed the records of patients who had coarctectomies at the University of Virginia Hospital after 1 year of age. Follow-up data for 5 years or more after surgery were available for 52 patients. Data from 23 similar patients from the Medical College of Virginia brought the total postoperative sample size to 75. The blood pressure of this group of patients did not differ significantly from that of the population at large. We conclude that successful repair of coarctation of the aorta in childhood or early adolescence does not lead to a higher-than-expected incidence of resting hypertension in childhood.

Failure of indomethacin to close persistent ductus arteriosus in infants weighing under 1000 grams.

Six preterm infants with a persistent ductus arteriosus, who failed to improve with conventional medical management, received indomethacin in an attempt to close the duct pharmacologically. All infants weighed less than 1000 g when the drug was administered. All showed a transient response to indomethacin; however, no infant demonstrated a permanent response, even though 5 of the 6 received multiple doses. One of the patients developed a severe episode of anuria, uraemia, and gastrointestinal bleeding. Of the 6 infants, 3 underwent subsequent successful surgical ligation of the ductus. It is suggested that the extremely preterm infant may be a 'poor responder' to indomethacin. Since the side effects of indomethacin may be life-threatening, it may be wise to consider surgical ligation in lieu of indomethacin administration in these infants.

Indicator dilution curves in the diagnosis of D-transposition of the great arteries in infancy.

Paired right and left atrial indicator dilution curves performed in a series of 17 patients with D-transposition of the great arteries (D-TGA) were reviewed. Taken together, the patterns obtained from patients who had trivial mixing between the pulmonary and systemic circulations were distinctive and easily recognizable. In the presence of substantial degrees of intracardiac mixing, however, the paired curves recorded become virtually identical and cannot be distinguished from curves recorded from patients with other forms of cyanotic congenital heart disease characterized by obligatory admixture. Thus paired atrial dye curves demonstrate a high degree of diagnostic specificity for the infant with D-TGA at greatest risk, normally those with a small intracardiac shunt. Such a procedure should facilitate early balloon atrial septostomy and obviate deterioration in the infant's condition due to prolonged catheter manipulation and/or angiography.

Application of an improved intracardiac fibreoptic system.

An improved fibreoptic in vivo haemoreflection system has been used in over 200 patients. Continuous recording of oxygen saturation while moving the catheter permits measurement of simultaneous pressure and oxygen saturation at almost an unlimited number of sites through the right heart. The oxygen saturation can be continuously monitored and the response is sufficiently fast to permit investigation of changes in oxygen saturation during portions of the cardiac cycle. Dye dilution curves have been recorded from over 200 patients. The only blood withdrawn for the dye dilution curve was the 3 ml needed for checking the calibration of the instrument. We have found that the calibration is extremely stable. In some instances where it has been deemed impractical to obtain blood for calibration, the calibration factor for each catheter may be used. In any case, the calibration check is performed at the end of the study and does not present problems of sterility. The calibration factor may yield a correction factor which then applies uniformly to all the cardiac output values obtained during the study.

Single coronary artery with a fistula to the main pulmonary artery in a patient with tetralogy of Fallot.

The presence of a single coronary artery arising in the anterior cusp and terminating in a large fistula to the main pulmonary artery was noted during the preoperative evaluation of a patient with tetralogy of Fallot. Recognition of this rare association dictated the use of a valved conduit to avoid injury to the left anterior descending coronary as it crossed the right ventricular outflow tract and permitted abolition of intracardiac shunting by ligation of the fistula. It is postulated that the increasing arterial saturation noted in this patient prior to intracardiac repair may have been related in part to progressive augmentation in flow through the coronary fistula to the main pulmonary artery.

Subendocardial blood flow in children with congenital aortic stenosis.

Subendocardial blood flow may be estimated from the ratio of flow to the subendocardium to myocardial oxygen consumption. The first may be estimated from the diastolic pressure time index (area between aortic and left ventricular (LV) pressure during diastole) and the latter by the tension time index (integral of LV pressure during systolic ejection). Subendocardial flow index (SEFI) averaged 1.27 (0.96-1.78) in 13 children with normal aortic valves. SEFI averaged 0.88 (0.43-1.65) in asymptomatic children with congenital aortic stenosis and was never greater than 0.9 in symptomatic children. Aortic valve area and systolic pressure difference did not correlate well with symptoms. SEFI and aortic valve area increased in 26 of 28 patients after surgery. However, 23 of 28 had varying degrees of aortic regurgitation following valvotomy. Since calculation of SEFI is not affected by aortic regurgitation, it would appear to be a more useful measure of surgical success than aortic valve area.

Age-related changes in size of the aortic valve annulus in man.

Data previously published in the literature, regarding the size of the aortic valve in man, have been reanalyzed. Aortic valve size increases at a slower rate than the surface area of the human body until maturity is reached at approximately 18 to 21 years of age. After that age, aortic valve size increases nearly linearly with age. There appears to be a slightly faster rate of aortic dilatation in males than in females, but this may be due to errors in estimating body surface area from only height and weight for obviously different body contours. Body surface area, thus, does not seem to be a good normalizing factor for the aortic valve size and the practice of referencing aortic valve sizes to the body surface area size should be discontinued. Alternate forms of using linear regression equations are reported and would appear to be preferable.

Prognostic implications of left ventricular function in endomyocardial disease in infants and children.

Hemodynamic factors measured at cardiac catheterization in 40 infants and children with chronic endomyocardial disease were analyzed in regard to subsequent clinical condition. The patients were followed for periods ranging from 2 months to 11 years (average 4.3 years) after initial cardiac catheterization. There were no statistically significant differences in left ventricular end-diastolic volume among survivors with no symptoms, survivors with persistent congestive heart failure, and nonsurvivors. Ejection fractions were depressed in about four fifths of patients with chronic endomyocardial disease and were significantly lower in the group of patients who died subsequently. LVEDP in patients who did not survive was significantly higher than in asymptomatic survivors, but there was too much overlapping of individual values to be of prognostic value. Left ventricular pressure-volume loops appeared to offer an improved, although more tedious, method of assessing LV function. In addition to offering information on LVEDV, LVEDP, and EjF, LV stroke work may easily be estimated from pressure-volume loops. There was generally good correlation between hemodynamic status assessed from pressure-volume loops and subsequent clinical outcome.