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Biomedical subjects

A S Nadas

Publications and source records attributed to A S Nadas.

At least 73 records · Page 4Linked to original sources
PubMed1976

The surgical management of discrete and diffuse supravalvar aortic stenosis.

Between 1956 and 1976, 18 patients underwent surgery for supravar aortic stenosis at the The Children's Hospital Medical Center, Boston. Discrete obstruction, present in 11, was treated by insertion of a prosthetic gusset placed across the area of narrowing and extending into the noncoronary sinus of Valsalva. There was one operative death. Residual gradients (measured in five patients) ranged from 4-55 mm Hg, one of which was supravalvar in location. Significant aortic regurgitation was not common preoperatively. The diffuse form of supravalvar obstruction, a more difficult surgical problem, was present in seven patients. There were three operative deaths. Complete relief of the pressure gradient was achieved only in one instance by insertion of a left ventricular-aortic bypass shunt diverting the majority of the cardiac output into the descending thoracic aorta. This patient is now asymptomatic 20 months following operation. On the basis of this experience, it is suggested that patients with the diffuse form of supravalvar obstruction, and perhaps even those with a hypoplastic annulus alone, would benefit from a left ventricular-aortic bypass shunt.

Adolescent↗
PubMed1976

Pathogenesis of paradoxical hypertension after coarctation resection.

The pathogenesis of paradoxical hypertension after resection of coarctation of the aorta was investigated by comparing the course of seven children undergoing repair of coarctation with five acyanotic children undergoing elective cardiovascular surgery. During the first 24 hours after surgery, all coarctation patients demonstrated a rise in systolic blood pressure (35 +/- 15.5 mm Hg; P less than 0.001), a significant depression in cold pressor test response, and only a slight elevation in plasma renin activity. In the next 24-72 hours, coarctation patients developed a rise in diastolic blood pressure (26.8 +/- 10.6 mm Hg; P less than 0.001), plasma renin activity (22.9 +/- 10.2/ml/hr; P less than 0.001) and fluid retention. By contrast, control patients had no significant postoperative changes. Abdominal pain occurred in five coarctation patients during the period of maximal plasma renin activity. The data suggest that the sympathetic nervous system may be responsible for the initial phase of hypertension after coarctation resection and that the renin angiotension system plays a major role in the second phase of hypertension and in the pathogenesis of mesenteric arteritis.

Abdomen↗
PubMed1976

The palliative Mustard operation for double outlet right ventricle or transposition of the great arteries associated with ventricular septal defect, pulmonary arterial hypertension, and pulmonary vascular obstructive disease. A report of eight patients.

Five patients with double outlet right ventricle, ventricular septal defect, pulmonary arterial hypertension and pulmonary vascular obstructive disease and three patients with complete d-transposition of the great arteries, ventricular septal defect, pulonary arterial hypertension and pulmonary vascular obstructive disease underwent an elective Mustard baffle operation. The ventricular septal defect was not closed. A large patent ductus arteriosus was divided in three patients. Seven of the eight patients are alive five to 32 months after surgery; one patient died 11 months after surgery. Cyanosis, dyspnea on exertion, and exercise limitation improved initially in all and has persisted in the survivors. In pre and postoperative hemodynamic studies in four patients, systemic arterial oxygen saturation and effective pulmonary blood flow increased from mean values of 70% to 90% and 1.7/min/m2 to 3.3 L/mon/m2, respectively. Absolute systemic and pulmonary flows, and pressures and resistances, were not significantly altered. Criteria for selection of patients with transposition of the great arteries of double outlet right ventricle who would benefit from a palliative Mustard procedure (Mustard atrial baffle without closure of the ventricular spetal defect) are: 1) severe symptoms; 2) pulmonary arteiral hypertension (75% systemic) with pulmonary vascular obstructive disease; and 3) pulmonary artieral oxygen saturation greater than systemic (ascending aorta) arterial oxygen saturation by approximately 10%.

Adolescent↗
PubMed1976

Hemodynamics after surgical repair with right ventricle to pulmonary artery conduit.

To assess the results of cardiac repair utilizing a right ventricular to pulmonary artery conduit, we reviewed postoperative hemodynamic data in 16 patients catheterized 0.5 to 5 years after repair. In 12 patients, a Hancock conduit (dacron conduit with porcine valve) was used; the conduit in the remaining four patients was made with an aortic homograft. All patients in whom an aortic homograft was utilized developed severe obstruction and calcification of their graft. The majority of patients, 9/12, with a Hancock conduit, had only mild to moderate conduit obstruction; the remaining three had severe obstruction (gradients greater than 70 mm Hg). The sites of Hancock conduit obstruction were at the distal end of the conduit in 8/12, proximal end of conduit in 6/12, and at the porcine valve in 4/12 patients. The data suggest that repair with a Hancock conduit is hemodynamically more satisfactory than with aortic homograft.

Adolescent↗
PubMed1976

Cardiovascular malformations associated with congenital anomalies of the urinary system. Observations in a series of 453 infants and children with urinary system malformations.

Thirty-four (8%) of 453 infants and children with urinary system malformations had cardiovascular malformations. Cardiac defects were seen frequently in Potter syndrome, unilateral renal agenesis, and horseshoe kidney. The most frequently encountered types of heart defects were ventricular septal defect (33%), endocardial cushion defect (15%), tetralogy of Fallot (12%), and patent ductus arteriosus (12%).

Abnormalities, Multiple↗
PubMed1976

Hepatic hemangioendothelioma: hemodynamic observations and treatment.

The clinical course of five infants with heptic hemangioendothelioma is reviewed. Hemodynamic abnormalities observed at cardiac catheterization included an increased cardiac output (range, 9.2 to 10.5 liters/min/sq m) with over 50% of this output being shunted through the arteriovenous malformation, an elevated right and left end diastolic pressure (8 to 10 mm Hg and 9 to 15 mm Hg respectively), a small systolic pressure gradient across the pulmonary outflow tract (4 to 6 mm Hg), and mild elevation of pulmonary artery pressure (range, 35/16 to 37/12 mm Hg). All four patients treated with prednisone improved while on therapy; three are well one to three years after cessation of therapy. One patient died from unrecognized congestive heart failure following discontinuation of prednisone and another before prednisone was started. We conclude that prednisone in high doses (2 to 4 mg/kg/day) with the addition of digitalis and diuretics for control of congestive heart failure is an effective treatment regimen for infants with hepatic hemangioendothelioma.

Blood Pressure↗
PubMed1976

Cardiovascular abnormalities associated with congenital diaphragmatic hernia.

Cardiovascular abnormalities were present in 11 of 48 (23%) patients with congeital diaphragmatic hernia. Cardiac abnormalities included congenital heart disease, compression of a major vascular structure, cardiac malposition, and abnormalities in pulmonary circulation. The differential diagnosis between isolated congenital diaphragmatic hernia and coexisting cardiac abnormality may be difficult and may require echocardiographic or invasive studies. Mortality in infants with diaphragmatic hernia and cardiovascular abnormalities is 73% in contrast to 27% in those without cardiac abnormalities.

Aortic Coarctation↗
PubMed1976

The clinical course of cardiac disease in Down's syndrome.

There was 230 patients with heart disease among 369 infants and children with Down's syndrome. The majority exhibited defects of the endocardial cushion variety and approximately one quarte had complete atrioventricular canals (CAVC). Pulmonary artery hypertension was uniform in catheterized patients in this latter group and frequent in all left-to-right shunts. Medical and surgical mortality was high (33%) in these 230 children and especially in those with CAVC and tetralogy of Fallot. Only 4% (76 of 1,916) of infants with critical heart disease in New England had Down's syndrome and the most frequent lesion encountered was complete atrioventricular canal.

Cardiac Catheterization↗
PubMed1976

Syndrome of intrahepatic biliary dysgenesis and cardiovascular malformations.

Peripheral pulmonary stenosis with or without intracardiac disease is described in 14 patients with intrahepatic biliary dysgenesis. Cardiovascular malformations were not present among a large group of patients with extrahepatic biliary dysgenesis. This association of intrahepatic biliary dysgenesis and vascular malformations is postulated to be a specific malformation syndrome resulting most probably from intrauterine infection. The cardiovascular disease is usually mild. The liver dysfunction varies in severity, and is accompanied by a notable hyperlipoproteinemia with secondary xanthomata which can be ameliorated by long-term treatment with cholestyramine resin and/or vegetable oil supplements.

Child, Preschool↗
PubMed1975

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.

Heart Defects, Congenital↗
PubMed1975

Bacterial endocarditis in children under 2 years of age.

The risk of bacterial endocarditis in infants with bacterial sepsis was assessed by review of clinical and autopsy records (1930 to 1972). There were 12 cases of bacterial endocarditis among 847 patients (1.4%) dying with bacterial sepis; a single survivor was noted during the entire period. Of the 12 autopsy patients, six had underlying congenital heart disease (CHD). Among 61 patients with bacterial sepsis associated with CHD, six acquired bacterial endocarditis (10%), whereas in 786 infants with sepsis but without underlying heart disease, only six developed bacterial endocarditis (0.8%) (P less than .01). There is a high mortality in infants with bacterial endocarditis, and an increased risk of it in infants with sepsis and CHD.

Age Factors↗
PubMed1975

Tricuspid atresia: clinical course in 101 patients.

The clinical profile and course of 101 patients with tricuspid atresia seen at the Children's Hospital Medical Center, Boston, were reviewed; the electrocardiograms, hemodynamic data, associated anomalies, complications of the malformation and surgical results were outlined and a definition of anatomic types and radiologic groups formed in order to facilitate therapeutic decisions. Overall survival to 15 years of age was approximately 50 percent. Tricuspid atresia type 1 (normally related great arteries), group A (decreased pulmonary vascularity) was the most frequent category (54 percent); without surgery, these patients had only a 10 percent chance of survival beyond the 1st year of life. Surgical intervention improved chance of survival to 15 years of age to 50 percent. Overall surgical mortality was 23 percent. The Waterston shunt is the procedure of choice in symptomatic small infants with diminished pulmonary flow (group A). Type II patients with increased pulmonary blood flow (group B) would benefit from a pulmonary arterial band. In contrast, patients with group B, type I atresia would rarely need a pulmonary arterial band. Patients with spontaneously changing hemodynamics (group C) usually require a shunt later in life than those in group A, with more favorable operative results. Our experience indicates the continued need of early surgical palliation. New surgical approaches, such as the right atrial-pulmonary arterial anastomosis, may result in a more prolonged survival.

Adolescent↗
PubMed1975

A forty-year review of bacterial endocarditis in infancy and childhood.

A retrospective review of 149 episodes of bacterial endocarditis (BE) in 141 patients under 25 years of age, at The Children's Hospital Medical Center from 1933 through June of 1972, demonstrates increasing survival and a distinct change in the frequency of underlying congenital heart disease and rheumatic heart disease (RHD). Certain forms of congenital heart disease such as tetralogy of Fallot, small ventricular septal defect, and aortic stenosis are at particular risk for BE. Following BE, patients with ventricular septal defect and tetralogy of Fallot have less morbidity and higher survival rates than children with aortic outflow lesions. over the entire time period, alpha Streptococcus is the most common pathogen and Staphylococcus aureus, second most frequent organism. Surgical correction in patients with congenital heart disease may offer the best form of prevention.

Adolescent↗
PubMed1975

Anomalous left coronary artery originating from the pulmonary artery. Report on 15 cases.

Fifteen infants and children with the diagnosis of anomalous left coronary artery from the pulmonary trunk have been encountered at the Children's Hospital Medical Center, Boston, Massachusetts from 1958 to 1973. After thorough clinical and laboratory evaluation, they have been treated by anticongestive measures. Nine patients have had ligation of the anomalous left coronary artery at its entrance into the pulmonary artery; one patient has undergone coronary bypass surgery. The lelctrocardiogram proved to be the most helpful diagnostic clinical laboratory test, Vectorcardiograms are valuable not only in diagnosis but also in the follow-up of the patients from the prognostic point of view. The most sensitive tool for the definitive diagnosis is an aortic rool angiogram; we have no false negatives or false positives with this method. The twelve patients with complete cardiac catheterization data could be divided into three groups, according to the pressure and magnitude of the left-to-right shunt at the pulmonary level. All patients with an appreciable le?T-TO-RIGHT SHUNT SURVIVED. Patients in whom no left-to-right shunt could be demonstrated by angiography died. Half of the patients with only small left-to-right shunt survived; The results of surgical and medical treatment, were identical within the three groups. Medical management in infancy, according to coronary care principles, with definitive surgical correction at a later age, is the preferred treatment. Ligation of the anomalous left coronary artery is recommended in severely symptomatic infants with documented left-to-right shunt at the pulmonary artery level, who do not respond to medical management.

Angiocardiography↗
PubMed1975

Sick sinus syndrome after surgery for congenital heart disease.

The course and prognosis of 16 infants and children with sick sinus syndrome associated with cardiac surgery is reviewed. The dysrhythmia was observed most ofter after extensive atrial reconstructive surgery in patients with transposition of the great arteries and with atrial septal defect. In 12 (75%) of the patients, sick sinus syndrome was detected in the immediate postoperative period. Tachyarrhythmias and bradyarrhythmias were presnet in 12 and isolated bradyarrhythmias in four. Temporary pacing was used in two and permanent pacing was required in five. Death in two non-paced patients was attributable to arrhythmias. Postmortem examination in one patient revealed a suture in the sinoatrial node. Careful attention to the anatomy of the sinoatrial node, its artery and the internodal tracts during surgery may prevent the development of sick sinus syndrome. In patients with dysrhythmia, a careful search should be undertaken to document the abnormal rhythm with the use of Holter monitoring. The insertion of a pacemaker is indicated in patients with tachyarrhythmias requiring cardioversion or antiarrhythmic drug therapy and those without adequate lower escape mechanisms.

Adolescent↗
PubMed1975

Aortic stenosis surgery in infancy.

During the past 14 years, 28 infants (23 males) underwent valvotomy for severe aortic stenosis at the Children's Hospital Medical Center in Boston. The median age was two months and the oldest patient was six months old. Congestive heart failure was present in all but two babies. Preoperatively, the electrocardiogram was abnormal in all, with left ventricular hypertrophy and a strain pattern being present in 19. At cardiac catheterization, the peak systolic ejection gradient (PSEG) ranged from 35-130 mm Hg (median 90 mm Hg). Associated cardiac lesions were present in 39%. Twenty-four infants underwent valvotomy with inflow occlusion. Four patients were operated upon using cardiopulmonary bypass. There were eight early and two late deaths. The 18 survivors have been followed from six months to 11 years (median five years). Only four are symptomatic. Mild aortic regurgitation developed postoperatively in six patients, moderate in one and severe enough to require valve replacement in another one. The electrocardiogram improved postoperatively in 15 patients, but became entirely normal only in one. Five children required a repeat valvotomy for residual stenosis 1-10 years after the original procedure (median four years). At this second operation, the majority of the valves were flexible and noncalcified, and valvotomy was accomplished without difficulty. One child who underwent valve replacement for aortic regurgitation at age two years is well seven years later.

Angiocardiography↗
PubMed1975

Extracardiac abnormalities in infants with congenital heart disease.

Extracardiac anomalies (ECA) occur in 25% of infants seen during the first year of life for significant cardiac disease. Often the ECA are multiple and one third of the affected infants have some established syndrome. In infants with endocardial cushion defect, patent ductus arteriosus, atrial septal defect, ventricular septal defect, malpositions, tetralogy of Fallot, and complex coarctation ECA occur in 25% or more of the cases. The most frequent ECA are in the musculoskeletal system or associated with a specific syndrome. The presence of an ECA significantly increases the mortality in infants with CHD.

Abnormalities, Multiple↗