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Biomedical subjects

R M Freedom

Publications and source records attributed to R M Freedom.

At least 271 records · Page 15Linked to original sources

Interruption of the aortic arch with aorticopulmonary septal defect. An anatomic review.

Interruption of the aortic arch may occur with aorticopulmonary septal defect (APSD) as part of a developmental complex. The anatomic details of 46 cases of interruption of the aortic arch with APSD revealed the following characteristics: (1) type A interruption of the aortic arch occurred nearly six times more commonly than type B interruption; (2) the APSD was variable in size and position, conforming to the types previously described; (3) the ventricular septum was usually intact, but a ventricular septal defect was present in six cases and occurred more frequently with type B interruption of the aortic arch; (4) subaortic stenosis was not present in any of the 16 cases in which adequate details were available to make a judgment. The association of APSD with interruption of the aortic arch in infancy is not uncommon. Evaluation of infants with APSD should thus include evaluation of the aortic arch. The occurrence of interruption of the aortic arch with an intact ventricular septum is distinctly unusual. In such cases an APSD should be suspected and sought.

Aorta↗

Space-occupying lesions of the myocardium: role of two-dimensional echocardiography in detection of cardiac tumors in children.

Four patients with space-occupying myocardial lesions were studied using electronically focused high-resolution two-dimensional echocardiography. In two patients with clusters of high-intensity echoes at various depths on the epicardial surface, histology confirmed the diagnosis of lymphosarcoma, showing patchy, malignant infiltrates of different thickness. The remaining two patients had very different features: the lesions appeared to be intrinsic to the posterior left ventricular wall. One patient who had arrhythmias and a small encapsulated noncontractile mass had a histologically proved rhabdomyoma. In the second patient fibroma was histologically confirmed. In these two patients the position of the lesions was confirmed by angiocardiography. Two-dimensional echocardiography greatly improved delineation of space-occupying cardiac masses and is an accurate method for confirming the presence of such lesions.

Adolescent↗

Mechanism of acquired right ventricular outflow tract obstruction in patients with ventricular septal defect: an angiocardiographic study.

Right ventricular outflow tract obstruction can complicate the natural history of patients with isolated ventricular septal defect. Although numerous pathologic mechanisms may be responsible for this phenomenon, it is less clear what the frequency is of each of these mechanisms in any cohort of patients studied in a single institution. We identified 20 patients with isolated ventricular septal defect from 1970 to 1981 who acquired a right ventricular outflow tract gradient of 25 mm Hg or more. They ranged in age at the initial catheterization investigation from 4 days to 23 months and at the subsequent study from 13 months to 8 years. Angiographically, 2 mechanisms were implicated in the 20 patients. Hypertrophy of right ventricular anomalous muscle bundles was identified in 19 of the 20 while hypertrophy of a malaligned infundibular septum (that is, classic tetralogy type) was identified in only 1 patient. These data indicate that acquired right ventricular outflow tract obstruction is rarely of the classic tetralogy type.

Aortic Valve↗

Cross-sectional echocardiographic diagnosis and subclassification of univentricular hearts: imaging studies of atrioventricular valves, septal structures and rudimentary outflow chambers.

We reviewed anatomic observations (surgical or autopsy), angiograms and echocardiograms from 44 patients with documented univentricular hearts. Thirty-three patients had univentricular heart of left ventricular type with an outflow or rudimentary chamber. Five had univentricular heart of right ventricular type, and six had univentricular heart of indeterminate types without a rudimentary chamber. Univentricular heart was correctly diagnosed by two-dimensional echocardiography in all but two of the 44 patients, including 25 of 27 double-inlet univentricular hearts, all five with absent left and all 12 with absent right atrioventricular connection. One of the two blind trabecular pouches was missed on echocardiography; the other was not seen on the angiogram but was present at autopsy. In 30 of 33 patients, univentricular heart of left ventricular type was correctly identified by imaging an anterosuperior and leftward or rightward outlet chamber, and in four of five patients with univentricular heart of right ventricular type, the anomaly was correctly identified by imaging the inferior and posterior position of the rudimentary outflow chamber near the crux of the heart. Two-dimensional echocardiography provides detailed analysis of atrioventricular connections, main chamber morphology, and rudimentary chamber size and position of noninvasive diagnosis and anatomic subclassification of univentricular hearts.

Adolescent↗

The role of cava-pulmonary (Glenn) anastomosis in the palliative treatment of congenital heart disease.

The value of the cava-pulmonary anastomosis (Glenn procedure) was assessed by reviewing the entire experience with this procedure in 83 children at The Hospital for Sick Children, Toronto, from 1961 to 1980. The over-all operative mortality rate was 9.6%, but only 2% in the second half of the series. The average follow-up is 9.4 years per patient. The late mortality rate has been 20%. By actuarial analysis, 84% of survivors were alive 9 years after operation; 54% had adequate palliation and 46% had required further operation. Long-term palliation was significantly better when the anastomosis was performed after 5 years of age. A previous arterial pulmonary artery shunt had no effect on either patient or shunt survival. Patients with tricuspid atresia had a better long-term survival rate than, but similar shunt survival to, those children with transposition, single ventricle, or miscellaneous cardiac anomalies. Angiography in 36 survivors showed patent shunts in 35 and no arteriovenous fistulas. Clinical status was not related to superior vena caval pressure or angiographic findings, indicating that Glenn shunt failure is a functional problem. The procedure is most useful for patients over 5 years of age who have complex heart disease not amenable to total repair. It is also on appropriate initial procedure in young patients over 18 months of age for whom direct atrium--pulmonary artery anastomosis is proposed as the future definitive treatment.

Adolescent↗

Two-dimensional echocardiographic identification of hemitruncus: anomalous origin of one pulmonary artery from ascending aorta with the other pulmonary artery arising normally from right ventricle.

Two-dimensional echocardiography (2DE) was performed on a 2300 gm newborn who presented with congestive heart failure. Clinical examination suggested left-to-right shunt with pulmonary hypertension. Cardiac catheterization and angiography demonstrated origin of the right pulmonary artery (RPA) from the aorta. Retrospectively, this feature (anomalous RPA) had been present on 2DE. A second patient aged 2 years had evidence of ventricular septal defect with large left-to-right shunt early in life. Gradual development of infundibular stenosis and clinical cyanosis ensued. 2DE showed subaortic ventricular septal defect with infundibular stenosis. Cardiac catheterization and angiography confirmed tetralogy of Fallot with origin of the left pulmonary artery (LPA) from the aorta. Retrospective review of 2DE showed the anomalous LPA arising from the side of the ascending aorta.

Angiocardiography↗

Echocardiographic features before and after the Jatene procedure (anatomical correction) for transposition of the great vessels.

Eight patients with complete transposition of the great vessels (TGA) underwent the Jatene procedure and repair of major associated anomalies. All were studied preoperatively by M-mode and two-dimensional echocardiography (2DE) and by cardiac catheterization. Six patients survived operation and were studied postoperatively by both echocardiographic methods; five also underwent cardiac catheterization and angiography. In these patients, 2DE accurately predicted the anatomic features preoperatively and provided an important adjunct to catheterization and angiocardiography.

Adolescent↗

Repair of major intracardiac anomalies associated with atrioventricular discordance.

Thirty-five patients with atrioventricular (AV) discordance underwent repair of major intracardiac defects. Ventricular septal defect (VSD) was the most frequently encountered lesion, present alone or in combination with other lesions in 86% of these patients. Pulmonary stenosis (51%) and tricuspid insufficiency (37%) were the other lesions encountered. The initial operative mortality of 8.6% is approaching that for these same defects when repaired in the patient with normal atrioventricular connections. However, the late mortality of 19% with an average follow-up of 4.4 years is higher than expected in the absence of AV discordance. Reoperation for residual or recurrent defects was required in 9 of the 32 survivors and was associated with a mortality of 33%. Seven of the 9 reoperations were required for tricuspid valve dysfunction. Elective repair of major anomalies in association with AV discordance can be accomplished safely, but these patients require careful long-term follow-up in anticipation of late problems.

Adolescent↗

Early experience with arterial repair of transposition.

Major anomalies associated with isolated complete transposition of the great arteries (TGA) can produce systemic pressure in the left ventricle without fixed stenosis of the left ventricular outflow tract. In this situation, arterial repair may be advantageous. Eight children, 10 days to 15 years old, underwent arterial repair of TGA. Major associated anomalies included large patent ductus arteriosus, bulging intraventricular septum, ventricular septal defect (VSD), tricuspid atresia, and the Taussig-Bing type of double-outlet right ventricle. There were 2 operative deaths related to acute left ventricular failure. The survivors underwent postoperative echocardiographic, hemodynamic, and angiographic assessment; all were in sinus rhythm and well six months to 2 1/2 years after operation. Residual lesions have been frequent but mild: aortic insufficiency (5), stenosis of the right ventricular outflow tract (1), trivial VSD (1), and stenosis of the right coronary artery (1). Left ventricular function is "normal" in 4 and unchanged from moderately depressed preoperative status in 1.

Adolescent↗

The morphology of the human newborn ductus arteriosus: a reappraisal of its structure and closure with special reference to prostaglandin E1 therapy.

The ductus arteriosus was examined in 103 fetuses and infants to define the normal structure, development, and morphologic features of the functional and anatomic phases of ductal closure. New contributions include ultrastructural observations and the light microscopic definition of the junctional regions of the ductus with the pulmonary artery and aorta. Observations relating to ductal closure include hyperemia of the ductal vasa vasorum, the presence of longitudinal muscle bands in the inner media, necrosis of the inner ductal wall, and organization of intraluminal thrombi. We found that a ductus arteriosus that fails to close normally is liable to show morphologic lesions, including intimal fibrinous deposits, medial hemorrhages, and dissecting aneurysms. The findings were used comparatively to investigate whether prostaglandin E1 infusion, given to maintain ductal patency in 7 infants with ductus dependent congenital heart disease, was associated with specific morphologic features. We could not delineate specific changes attributable to its use.

Age Factors↗

Rapid evolution from "normal" left ventricular outflow tract to fatal subaortic stenosis in infancy.

Serial clinical, echocardiographic, haemodynamic, and angiocardiographic data support the conclusion that over four months severe discrete subaortic stenosis evolved from a previously angiocardiographically normal left ventricular outflow tract in an infant who had a successful repair of thoracic aortic coarctation. This case supports those who suggest that a myocardial factor may play an important role in the change in form and function of some congenitally malformed hearts.

Angiocardiography↗

Anatomic correction of transposition of the great arteries: pre- and postoperative cardiac catheterization, with angiocardiography in five patients.

Six of eight patients survived anatomic correction of transposition of the great arteries and repair of associated cardiovascular anomalies at the Hospital for Sick Children, Toronto, Canada. Two of the six survivors also had tricuspid atresia, and continuity between the right atrium and the subaortic outlet chamber in these patients was provided by a valved external conduit, in addition to the arterial switch and coronary artery reimplantation. Five of the six patients have undergone complete postoperative clinical, hemodynamic and angiocardiographic investigation and form the basis of this communication. Our present indications for anatomic repair are discussed.

Adolescent↗

Pulmonary artery stenosis following aortopulmonary anastomoses.

From 1965 to 1979, 44 patients with Potts and 50 with Waterston aortopulmonary anastomoses were studied angiographically. Fifty-two of the 95 shunts had been banded to limit growth of the anastomosis. Later the internal diameter of the anastomosis was measured in 34 children when the cardiac defect was repaired. On those with late measurements, growth was limited effectively in 17 of the 18 (94%) shunts that had been banded, whereas five of the 16 (31%) unbanded anastomoses grew to more than 6.5 mm internal diameter (p = 0.05). The difference in incidence of moderate or severe stenosis of the pulmonary artery near or at the anastomosis nearly reached a significant level (p = 0.07), occurring in 50% of children with banded shunts in comparison with 31% of children with unbanded shunts. Mean pulmonary artery pressures were obtained in 77 children, 36 with potts and 41 with Waterston shunts. Six of 43 with a banded anastomosis had a mean pulmonary artery pressure above 30 mm Hg, the highest being 43 mm Hg. Seven of 34 children with an unbanded anastomosis had a mean pulmonary artery pressure of 30 mm Hg or more, and in three the pressures were over 50mm Hg. In unbanded Potts or Waterston shunts the incidence of pulmonary artery stenosis was 60%. This high incidence discourages the use of these aortopulmonary anastomoses if other shunts can be constructed safely and effectively.

Aorta↗

Results of right atrial to right ventricular and right atrial to pulmonary artery conduits for complex congenital heart disease.

The Fontan procedure was initially proposed for tricuspid atresia (TA). We describe our experience with modifications of this operation and its application to previously uncorrectable congenital lesions. From 1975 to 1979, 26 patients have undergone a Fontan-like procedure, at a mean age of 14 years (range: 3 months to 23 years). Nineteen patients had TA, one patient had mitral atresia, four patients had a univentricular heart, one patient had a "criss-cross" heart, and one patient had pulmonary atresia. Previous procedures included eight Glenn shunts, 18 systemic to pulmonary artery (PA) shunts, two PA bands, and two atrial septectomies. Thirteen patients underwent right atrial (RA) to PA connections, with a valved conduit in nine patients and without in four. Two patients had simultaneous Glenn shunts. Thirteen had RA to right ventricular (RV) conduits, with a valve in 12 patients and without in one. There were five early deaths (<30 days, 19%) and no significant difference between the RA to PA connection (four deaths of 13) versus the RA to RV connection (one death of 13). The mortality rate was higher in patients undergoing RA to PA connection without valved conduit (one death of nine with a valve, three deaths of four without, p < 0.05), while the Glenn shunt did not affect mortality (one death of seven with, three of six without, p < 0.1). There were no late deaths (mean follow-up: 24 months). Seven patients underwent recatheterization with a mean RA pressure of 14 mmHg (range: 9--25 mmHg). Thus, the "Fontan" procedure can be done with an acceptably low mortality with good functional results, both for TA and other complex lesions.

Adolescent↗