Population-based study of congenital heart defects in Down syndrome.

Mental retardation and hypotonia are found in virtually all Down syndrome (DS) individuals, whereas congenital heart defects (CHDs) are only present in a subset of cases. Although there have been numerous reports of the frequency of CHDs in DS, few of the studies have had complete ascertainment of DS in a defined geographic area. The Atlanta Down Syndrome Project, a population-based study of infants born with trisomy 21, provides such a resource. In the first 6.5 years of the study, 243 trisomy 21 livebirths were identified in the five-county Atlanta area (birth prevalence: 9.6/10,000). Cardiac diagnoses were available on 227 (93%) of the cases and 89% of these evaluations were made by echocardiography, cardiac catheterization, surgery, or autopsy. Of the 227 DS infants, 44% had CHDs including 45% atrioventricular septal defect (with or without other CHDs), 35% ventricular septal defect (with or without other CHDs), 8% isolated secundum atrial septal defect, 7%, isolated persistent patent ductus arteriosus, 4% isolated tetralogy of Fallot, and 1% other. This report is unique in that it contains the largest number of trisomy 21 infants ascertained in a population-based study where modern techniques for diagnosing cardiac abnormalities predominate.

Follow-up of surgical correction of vascular anomalies causing tracheobronchial compression.

Between January 1977 and January 1990, 44 patients with symptomatic vascular rings/slings required surgical intervention at this center. Nineteen patients had double aortic arch (group I); 13 patients had vascular ring consisting of right aortic arch, anomalous origin of the left subclavian artery, and ligamentum arteriosus (group II); eight patients had innominate artery compression (group III); and four patients had pulmonary artery sling (group IV). Three patients had complex congenital heart defect and died secondary to it and are excluded from the study. Follow-up was obtained on 31 patients (76%). The follow-up period ranged from 0.4 years to 10.9 years, with a mean of 3.6 years. Seventy percent of the overall group were asymptomatic, and 30% of patients continued to have upper and lower respiratory symptoms on late follow-up. One third of patients in groups I and II, who underwent surgical repair, continue to have symptoms. Patients who have persistent symptoms should be further evaluated with PFTs, MRI, and bronchoscopy, and may benefit from aortopexy. Patients with innominate artery compression and pulmonary artery sling do well soon after surgery with relief of most of their symptoms.

Effects of venovenous extracorporeal membrane oxygenation on cardiac performance as determined by echocardiographic measurements.

We evaluated the effects of venovenous extracorporeal membrane oxygenation (ECMO) on cardiac performance by echocardiographic measurements in 15 infants. Heart rate and blood pressure were also recorded. Echocardiographic measurements included aortic and pulmonary peak blood flow velocities, pulmonary time to peak velocity, left ventricular shortening fraction, velocity of circumferential fiber shortening corrected for heart rate, and peak systolic wall stress before, during, and after venovenous ECMO. Pre-ECMO echocardiograms showed borderline or normal indexes of cardiac function. After initiation of venovenous ECMO, all infants had normalization and no infant had deterioration of cardiac performance. The inotropic agents dopamine and dobutamine were decreased from average doses of 12 and 3.6 micrograms/kg per minute, respectively, to 3.7 and 1.3 micrograms/kg per minute, respectively, within 8.8 hours of the institution of venovenous ECMO. During this time the mean arterial pressure remained stable, and the heart rate decreased (169 +/- 21 vs 136 +/- 15 beats/min; p < 0.001). During the course of ECMO there were no changes in left ventricular shortening fraction, velocity of circumferential fiber shortening corrected for heart rate, or aortic peak blood flow velocities. Pulmonary artery peak blood flow velocity (69 +/- 22 vs 92 +/- 28 cm/sec; p = 0.04) and pulmonary time to peak velocity improved (47 +/- 11 vs 65 +/- 16 msec; p = 0.026). We conclude that venovenous ECMO does not have deleterious effects on cardiac performance.

The usefulness of echocardiography in the surgical management of infants with congenital heart disease.

Between January 1988 and August 1991, at The Children's Heart Center, Atlanta, 83 infants with congenital heart defects were diagnosed by echocardiography and underwent surgery without cardiac catheterization. The diagnostic categories included 46 infants with left heart obstructive lesions, 19 infants with cyanotic heart lesions, and 18 infants with miscellaneous lesions. Forty-five infants (55%) underwent surgery under cardiopulmonary bypass. There were three errors in diagnosis, yielding a diagnostic accuracy of 95%. Many infants with congenital heart disease can be accurately and completely diagnosed by echocardiography and can safely undergo surgery without cardiac catheterization.

Prostaglandin-induced hyperostosis. A case report.

The use of prostaglandin-E1 (PGE1) to maintain patency of the ductus arteriosus in infants with ductal-dependent congenital heart disease is now well established. A 2.5-month-old child with cyanotic heart disease who required long-term PGE1 infusions; developed widespread periosteal reactions during the course of therapy. Prostaglandin-induced subperiosteal hyperostosis should now be considered in the differential diagnosis of neonatal cortical proliferation.

The cardiovascular abnormalities associated with duplicated segments of chromosome 7.

Congenital heart disease is an integral part of many genetic syndromes such as the major trisomies 13, 18, and 21. Little information, however, is available with reference to the incidence of cardiac anomalies in the trisomy 7 syndromes. Two patients with partial trisomy 7q, one of whom had congenital heart disease, are presented. A review of the literature reveals incomplete description of the cardiovascular abnormalities in the majority of case reports of patients with this syndrome, however, when described it appears that there are no specific defects associated with trisomy 7p and 7q, but only an increased frequency of occurrence. Further clinical and postmortem data regarding details of the congenital heart defects associated with trisomy 7 is required to confirm this preliminary observation.

Management of the premature infant with a patent ductus arteriosus.

The maturation of the lung is one of the greatest challenges the premature infant must face after birth. Premature infants have been observed to have a higher prevalence of patency of the ductus arterious, presenting the physician with a dilemma and a challenge. This article discusses the clinical and pathophysiologic manifestations and the management of patent ductus arteriosus in the premature infant.

Extracardiac atrial pedicle conduit repair of partial anomalous pulmonary venous connection to the superior vena cava in children.

Between June, 1982, and July, 1983, 6 children with partial anomalous pulmonary venous connection to the middle or high segment of the superior vena cava (SVC) underwent repair of the anomaly by division of the SVC proximal to the site of entry of the anomalous pulmonary veins. Continuity between the cephalad end of the SVC and the right atrium was established by direct anastomosis to the right atrial (RA) appendage or by creation of a pedicle conduit of RA appendage, RA free wall, and pericardium. The anomalous pulmonary veins remained in situ on the lower segment of SVC, blood being directed to the left atrium through an atrial septal defect by a pericardial patch placed within the right atrium well away from the sinoatrial node, anomalous pulmonary veins, and cavoatrial junction. All children have survived, remain in normal sinus rhythm, and have no evidence of vena caval or pulmonary venous obstruction. Follow-up cardiac catheterizations, angiocardiograms, and Holter recordings support the efficacy of this technique as an alternative in the management of anomalous pulmonary veins joining the SVC well above the cavoatrial junction.

Echocardiographic characteristics of premature infants with patient ductus arteriosus.

As part of a multicenter collaborative study, M-mode echocardiograms were obtained shortly after birth on 3,559 premature infants with birth weight less than or equal to 1,750 g. Of these infants, 1,496 did not develop a cardiac murmur or other signs of a "hemodynamically significant" patent ductus arteriosus (PDA). Echocardiographic parameters from this "normal" group were compared with results obtained from 415 infants in whom PDA was diagnosed on the basis of clinical findings alone, irrespective of the echocardiogram (PDA group). The best discrimination between the two groups, when considering a single parameter, was provided by a left atrial to aortic root ratio (LA/AO) of 1.40, a left ventricular to aortic root ratio (LV/AO) of 2.10, or a left ventricular systolic time interval ratio (LPEP/LVET) of 0.27. Multivariate analysis demonstrated that better separation between the two groups occurred when the left atrial to aortic root ratio and the left ventricular systolic time interval ratio were considered jointly. Because of a large degree of overlap of all echocardiographic variables between the normal group and the group with PDA, the echocardiogram alone was not a good indicator of PDA. However, when used in conjunction with a priori estimates of the probability of PDA (based, for example, on birth weight and degree of respiratory disease), use of echocardiographic data was found to improve the detection of hemodynamically significant patent ductus arteriosus in premature infants.

The Blalock-Taussig shunt. Low risk, effective palliation, and pulmonary artery growth.

The Blalock-Taussig shunt has been used at our institution in 64 infants with cyanotic congenital heart disease who required palliation. Thirty-one of these children were less than 2 months of age at the time of operation. There were no early shunt closures. There were two hospital deaths (3%). There was only one hospital death in the 31 patients less than 60 days old. According to a life-table analysis, 87% +/- 9% (+/- 95% confidence limits) of the shunts were functioning at 1 year and 78% +/- 12% at 2 years. Results are similar in the subgroup of children less than 60 days of age at the time of operation or in the subgroup of children weighing less than 3,999 gm at operation. In infants with small pulmonary arteries, pulmonary arterial growth was excellent (ipsilateral pulmonary artery/descending aorta ratio 0.70 leads to 0.95 in 550 days, p less than 0.001; contralateral ratio 0.73 leads to 0.99 in 550 days, p less than 0.001). The Blalock-Taussig shunt can be performed with low risk, provides excellent palliation, and is associated with excellent pulmonary artery growth.

Evaluation of the preterm infant for patent ductus arteriosus.

As a first step in a multicenter, collaborative project to study the role of indomethacin in the management of patent ductus arteriosus in premature infants, a diagnostic scheme was developed, on an a priori basis, by a consensus of the participating neonatologists and pediatric cardiologists. The scheme, which utilizes clinical and noninvasive findings, was designed to detect infants with a "hemodynamically significant" patent ductus arteriosus (PDA). Among 1,689 infants with birth weight less than 1,750 g who were monitored during the first year of the study, 342 (20.2%) met the criteria for PDA. Rates were higher for smaller infants (42% with birth weight less than 1,000 g) than for larger infants (7% with birth weight 1,500 to 1,750 g). Although study protocol did not require a direct procedure to confirm the diagnosis of PDA, a marked decrease in the presence of most criteria was noted following surgical ligation of the ductus. Although the echocardiographic criterion (ratio of left atrium to aorta [LA/Ao] greater than or equal to 1.15) proved to have a low specificity for PDA, the data suggest that the overall scheme led to a very low rate of false-positive diagnosis. Following the application of the scheme for 1 year at 13 clinical centers, it has been shown to be a highly acceptable means of detecting infants with PDA.

Range-gated pulsed Doppler ultrasonographic evaluation of carotid arterial blood flow in small preterm infants with patent ductus arteriosus.

Range-gated pulsed Doppler (RGPD) ultrasonography was utilized to study the effect of a patent ductus arteriosus (PDA) on carotid arterial blood flow in small preterm infants. Carotid arterial flow velocity studies were performed on 23 preterm infants, sampling right and left carotid arteries. Studies on seven infants after PDA ligation and on seven who developed no evidence of PDA were used as controls. A strong relationship was demonstrated between diastolic reversal in the carotid arteries and PDA. The results of this study indicate that the RGPD flow velocity curve from the carotid artery is more sensitive than M-mode echocardiography or clinical examination in detecting PDA, and that PDA in small preterm infants is associated with a distinct abnormality in the carotid arterial flow pattern.

Critical aortic coarctation: patch aortoplasty in infants less than age 3 months.

Twenty-three infants less than age 3 months (mean age 31 days) underwent patch aortoplasty for relief of coarctation of the aorta. All had intractable congestive heart failure, despite aggressive medical therapy. Each infant had other cardiac anomalies, including patent ductus arteriosus (83 percent) and ventricular septal defect (74 percent). All patients underwent closure of the ductus arteriosus and patch angioplasty of the aorta to produce a luminal diameter of at least 16 mm. In addition, 9 of the 17 patients (53 percent) with a large shunt ventricular septal defect underwent pulmonary arterial banding. There was one hospital death 42 days after operation secondary to bowel perforation and sepsis. Hospitalization beyond 21 days postoperatively was always due to other unrepaired cardiac lesions. The three late deaths at 3, 9 and 18 months after operation were associated with additional major anomalies. Fourteen patients have had postoperative catheterization. No gradient was found across the site of coarctation repair, but one patient had a gradient between the left carotid and left subclavian arteries. Surgical repair of critical coarctation of the aorta in infants can safely be offered despite the presence of other cardiac anomalies.

Late complications following surgical repair of total anomalous pulmonary venous return below the diaphragm.

Between May, 1975, and June, 1977, we surgically repaired an infracardiac total anomalous pulmonary venous return in 4 infants under deep hypothermic cardiac arrest. All patients had pulmonary hypertension and a patent ductus arteriosus. All survived operation and required positive end-expiratory pressure with mechanical ventilation. Late complications included patent ductus arteriosus not visualized at initial catheterization, breakdown of an oversewn atrial septal defect repair, and pulmonary venous obstruction despite an anastomosis diamter of 1.5 to 2.5 cm. At reoperation, there was scarring and contraction at the junction of the pulmonary veins and left atrium. One infant with these complications died post-operatively. In another patient, there was kinking of the left lower pulmonary vein at its juncture with the left atrium. In view of these complications we currently recommend the following: ligation of the ductus arteriosus regardless of catheterization findings; a right-sided approach to avoid pulmonary vein kinking; prosthetic patch closure of the atrial septal defect to avoid excessive tension on suture lines and to maintain maximum left atrial size; stellate anastomosis to provide the largest possible drainage channel; awareness that an unusually high positive end-expiratory pressure may be required postoperatively; and early recatheterization.

Results of pulmonary arterial banding in infancy. Survey of 5 years' experience in the New England Regional Infant Cardiac Program.

The results of pulmonary arterial banding in 238 infants, 12 percent of the infants admitted to the New England Regional Infant Cardiac Program, is reviewed. Overall survival to age 1 year was 63 percent. Survival was least likely (37 percent) in those who required banding within the 1st month of life. Additional surgery decreased the survival rate in those operated on after 1 month of age. Infants with anomalies for which no corrective surgical procedure is available (23 of 238) have only a 30 percent chance of survival. Those with lesions correctable within the 1st year (133 of 238) have a 74 percent survival rate; 52 percent (82 of 238) of those for whom a curative operation is available after the 1st year survive. These pulmonary arterial banding data coupled with results of primary correction should provide the data base required for an intelligent decision in respect to appropriate surgical treatment of infants with critical heart disease.