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Biomedical subjects

A S Nadas

Publications and source records attributed to A S Nadas.

At least 19 recordsLinked to original sources
PubMed1990

Long follow-up (to 43 years) of ventricular septal defect with audible aortic regurgitation.

From 1946 to March 1989, 92 patients (33 women and 59 men) were seen with ventricular septal defect (VSD) and audible aortic regurgitation (AR). The VSD was subcristal in 62 patients, subpulmonary in 21 and unknown in the remaining 9. The median age of onset of AR was 5.3 years. The risk of developing AR was 2.5 times greater in those with a subpulmonary VSD. The aortic valve was tricuspid in 90% and bicuspid in 10%. Prolapse was seen in 90% of those with subcristal VSD and in all with subpulmonary VSD. Pulmonary stenosis was seen in 46% of the patients with gradients ranging from 10 to 55 mm Hg. The incidence of infective endocarditis was 15 episodes/1,000 patient years. Among 20 patients followed medically, for 297 patient years, 1 died (1959) and most have been stable, including 2 followed for greater than 30 years. In the 72 patients operated on, there were 15 perioperative and 5 late deaths. Operations consisted of VSD closure alone in 7, VSD closure and valvuloplasty in 50 and VSD closure and aortic valve replacement in the other 15. Valvuloplasty was more effective in those operated on under age 10 compared to those older than 15 years (46 vs 14%). The durability of the valvuloplasty was 76% at 12 years and 51% at 18 years.

Actuarial Analysis↗
PubMed1986

Long-term follow-up of valvotomy before 1968 for congenital aortic stenosis.

The clinical course of 59 patients who underwent valvotomy for aortic stenosis before 1968 was reviewed. All were older than 1 year at the time of operation. Mean follow-up period was 17.7 years. Forty-six patients are alive; 26 (57%) are 30 to 40 years and 6 (13%) are older. Actuarial analysis indicated that the probability of survival was 94% at 5 years and 77% at 22 years. Thirteen patients died, 7 suddenly. Among the latter, significant obstruction or regurgitation was present in the 4 who underwent catheterization 0.9 to 7.2 years before death, 2 of whom were symptomatic and 2 with progression of a strain pattern on electrocardiogram. Surgery was recommended but declined by the latter 2 patients. Reoperation was carried out in 21 patients (36%), 3 (12%) of whom died. Actuarial analysis revealed the probability of reoperation to increase from 2% at 5 years to 44% at 22 years. Bacterial endocarditis occurred on 4 occasions in 3 patients, 1 of whom died suddenly during treatment. The incidence of endocarditis was 3.8 episodes/1,000 patient-years. Actuarial analysis of serious events, defined as death, reoperation and endocarditis, with the most serious of these and each patient being represented only once, indicated the probability of being free of such an episode to be 92% at 5 years, decreasing to 39% at 22 years. These data emphasize the palliative nature of valvotomy and the meticulous follow-up so necessary in these patients.

Actuarial Analysis↗
PubMed1986

Perinatal risk assessment for patent ductus arteriosus in premature infants.

Data from 2107 inborn premature infants monitored for hemodynamically significant patent ductus arteriosus were used to develop means for clinically assessing at birth the risk of developing patent ductus arteriosus during the first 30 days of life. The overall 30-day incidence rates in birth weight categories 500 to 999, 1000 to 1499 g, and 1500 to 1750 g were 41, 17, and 7%, respectively. At-birth risk estimates obtainable from the derived multivariate functions ranged from 0 to 78% for the 500 to 999 and 1000- to 1499-g categories, and from 0 to 20% for the 1500- to 1750-g category. The derived risk functions provide for enhanced selectivity in the application of measures for the prevention of patent ductus arteriosus.

Adolescent↗
PubMed1985

Risk factors for retrolental fibroplasia: experience with 3,025 premature infants. National Collaborative Study on Patent Ductus Arteriosus in Premature Infants.

The rate of retrolental fibroplasia in relation to prenatal and neonatal characteristics was explored on the basis of a cohort of 3,025 neonates with birth weight less than 1,750 g. The overall rate of retrolental fibroplasia of any degree at hospital discharge was 11%, varying from 43% for those with birth weight between 500 and 749 g to 3% for those in the 1,500- to 1,750-g category. Among the potential determinants, the main interest was in nonhyperoxic characteristics, conditional on measures of prematurity and oxygen supplementation. Maternal diabetes and antihistamine use during the last 2 weeks of pregnancy were associated with significantly higher rates of retrolental fibroplasia, whereas toxemia was associated with lower rates. Frequent apneic spells, bronchopulmonary dysplasia, and sepsis in the neonate were also associated with significantly higher rates. On the other hand, the data indicate no independent role of low Apgar score, intraventricular hemorrhage, exchange transfusion, patent ductus arteriosus, or certain other characteristics previously postulated as risk factors.

Anemia↗
PubMed1984

Clinical course to 1 year of age in premature infants with patent ductus arteriosus: results of a multicenter randomized trial of indomethacin.

Reported are 1-year follow-up results of a randomized clinical trial comparing three strategies of managing clinically significant patent ductus arteriosus at the time of diagnosis in premature infants: (1) immediate administration of a three-dose course of intravenously administered indomethacin in addition to usual medical therapy (fluid restriction and use of diuretics or digitalis or both), with surgery as a backup measure, (2) usual medical therapy alone initially, with indomethacin as the first and surgery as the final backup measure, and (3) usual medical therapy alone initially, with surgery alone as backup. Of primary concern were the relative merits of these three managements strategies in the terms of the long-term occurrence of a wide range of health problems. Although at the time of neonatal hospitalization there was a significant excess of bleeding episodes in infants receiving indomethacin as part of initial treatment, and a significantly higher rate of retrolental fibroplasia in the those given usual medical therapy with surgery as backup, there were no statistically significant differences at 1 year of age related to these intermediate outcomes. In other regards, too, the treatment strategies appeared interchangeable in terms of the 1-year outcome.

Bronchopulmonary Dysplasia↗
PubMed1984

Is routine preoperative cardiac catheterization necessary before repair of secundum and sinus venosus atrial septal defects?

Between January 1976 and July 1983, 217 patients with atrial septal defect underwent surgical repair at Children's Hospital. Thirty with a primum atrial septal defect and 26 who underwent cardiac catheterization elsewhere before being seen were excluded from analysis. Of the 161 remaining patients, 52 (31%) underwent preoperative cardiac catheterization, 38 because the physical examination was considered atypical for a secundum atrial septal defect and 14 because of a preexisting routine indication. One hundred nine (69%) underwent surgery without catheterization, with the attending cardiologist relying on clinical examination alone in 5, additional technetium radionuclide angiocardiography in 5, M-mode echocardiography in 13 and two-dimensional echocardiography in 43; both M-mode echocardiography and radionuclide angiography were performed in 24 and two-dimensional echocardiography and radionuclide angiography in 19. Since 1976, there has been a trend toward a reduction in the use of catheterization and use of one rather than two noninvasive or semiinvasive techniques for the detection of atrial defects. Of the 52 patients who underwent catheterization, the correct anatomic diagnosis was made before catheterization in 47 (90%). Two patients with a sinus venosus defect and one each with a sinus venosus defect plus partial anomalous pulmonary venous connection, partial anomalous pulmonary venous connection without an atrial septal defect and a sinoseptal defect were missed. Of 109 patients without catheterization, a correct morphologic diagnosis was made before surgery in 92 (84%). Nine patients with a sinus venosus defect, three with sinus venous defect and partial anomolous pulmonary venous connection, four with partial anomalous pulmonary venous return without an atrial septal defect and one with a secundum defect were incorrectly diagnosed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1983

Fixed subaortic stenosis in the young: medical and surgical course in 83 patients.

Eighty-three patients aged 11 months to 25 years were followed up a median of 6.1 years (range 8 days to 24 years) after diagnosis of fixed subaortic stenosis (SAS). Fourteen (17%) had significant noncardiac defects and 47 (57%) had additional cardiac malformations. The left ventricular (LV) outflow gradient increased in 25 of 26 patients catheterized more than once before surgery. Of 15 patients less than 12 years old with gradients less than or equal to 40 mm Hg, 10 ultimately underwent operation after developing severe obstruction; another has progressed to a gradient of 45 mm Hg at 6 years of age. Before surgery (at a median age of 12 years), 55% had aortic regurgitation (AR), which was usually mild. Infective endocarditis occurred in 12% of the group, with a frequency of 14.3 cases per 1,000 patient-years. Seventy-four patients were operated on, with 6 early (8%) and 7 late (9%) deaths. Twelve underwent reoperation to relieve residual obstruction. Surgery reduced gradients in patients with discrete SAS from 83 +/- 33 to 29 +/- 30 mm Hg, but in 6 patients with tunnel SAS the reduction was less satisfactory. AR was absent or mild in most patients postoperatively. When the gradient was reduced to less than 80 mm Hg, infective endocarditis did not occur unless there were other residual lesions. These data suggest that it is reasonable to resect discrete SAS in children less than 10 to 12 years old with LV outflow gradients greater than or equal to 30 mm Hg.

Adolescent↗
PubMed1983

Overall prognosis as the primary criterion of outcome in a clinical trial.

In a randomized trial on premature infants, with follow-up to 1 year of age only, the goal is to identify which one among the compared strategies of intervention affords the best outcome throughout life. This requires the assessment of lifetime prognosis at the end of follow-up as the primary criterion of outcome. Moreover, with the treatments potentially influencing a variety of organ systems, it is necessary to combine their separate prospects into an overall prognosis as a basis for identifying the preferable mode of intervention. The development of the scheme of rating overall prognosis posed considerable challenges, in theory as well as in application.

Clinical Trials as Topic↗
PubMed1983

Effects of indomethacin in premature infants with patent ductus arteriosus: results of a national collaborative study.

Among 3559 newborn infants with birth weight less than 1750 gm, 421 developing a hemodynamically significant patent ductus arteriosus were entered into a randomized trial to evaluate the role of indomethacin in the management of PDA. Indomethacin given concurrently with usual medical therapy at the time of diagnosis resulted in ductal closure in 79%, versus 35% with placebo (P less than 0.001). Indomethacin as backup to usual medical treatment resulted in similar closure rates. To assess overall effects through hospital discharge, three management strategies were compared. Although mortality did not differ significantly, infants given indomethacin only if usual therapy failed (strategy 2) had a lower incidence of bleeding than those to whom indomethacin was given with initial medical therapy (strategy 1) and lower rates of pneumothorax and retrolental fibroplasia than those to whom no indomethacin was administered, with surgery the only backup to medical therapy (strategy 3). Thus the administration of indomethacin only when medical treatment fails appears to be the preferable approach for the management of symptomatic PDA in premature infants.

Clinical Trials as Topic↗
PubMed1983

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.

Clinical Trials as Topic↗
PubMed1982

Mannheimer lecture.

Explore the source record for details and available documents.

Clinical Trials as Topic↗
PubMed1982

Developmental delay in infants with congenital heart disease. Correlation with hypoxemia and congestive heart failure.

The mental and motor development of 173 infants with congenital heart disease was assessed by means of the Bayley Scales of Infant Development and clinical neurological examinations. The relationship between age, sex, congestive heart failure, hypoxemia, hospitalization, and test results was evaluated. The presence of congestive heart failure was found to be significantly associated with both mental and motor development delay. Hypoxemia and hospitalization were associated with delayed motor development. Developmental delay could be recognized as early as 2 months of age.

Age Factors↗
PubMed1980

Exercise-induced ventricular ectopy in children and young adults with complete heart block.

Twenty-five children and young adults with complete heart block and 50 normal control subjects were maximally exercised on a treadmill and their electrocardiograms were analyzed for the presence and degree of ventricular ectopy activity. Sixty-eight % (17 of 25) of the heart block patients and significant ventricular ectopy (frequent unifocal ectopy or worse) on exercise compared to 2% (one of 50) of the controls (p = less than 0.01). In the patients with block there was a significant trend toward more frequent and more severe ectopy with increasing age (p = less than 0.05) independent of heart rate. More severe ventricular ectopy was also seen in those patients with QRS prolongation (p = less than 0.05). No significant differences were found between the 14 patients with isolated "congenital" heart block, the seven with associated defects, and the four with surgically acquired block. We believe that severe ventricular ectopy is common at exercise in patients with complete heart block and they may have an increased risk for sudden death.

Adolescent↗