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Biomedical subjects

R D Rowe

Publications and source records attributed to R D Rowe.

At least 145 records · Page 8Linked to original sources
PubMed1977

Aneurysm of the membraous septum in ventricular septal defect.

An aneurysm of the membranous septum was found frequently in patients with ventricular septal defect; although appearance at catheterization during infancy was not common, aneurysms were detected in about half of the patients older than 2 years of age. A significant decrease in the left-to-right shunt occurred with the development of an aneurysm, but progression to complete spontaneous closure was not seen in any patient. In three older patients, an aneurysm of the membranous septum "disappeared" with time, even though complete spontaneous closure had not occurred.

Child↗
PubMed1976

Aneurysm of the atrial septum in tricuspid atresia: diagnosis during life and therapy.

Massive aneurysmal dilatation of the foramen ovale was diagnosed angiocardiographically in a patient with tricuspid atresia. The angiographic findings are distinct for this condition, and the pathogenesis appears to be related to a restrictive atrial communication in the patient with obligatory right to left shunting at atrial level. The anatomic potential for atrial restriction in the patient with tricuspid or pulmonary atresia, intact ventricular septum and diminutive right ventricle necessitates balloon atrial septostomy at the initial diagnostic cardiac catheterization. In the patient with aneurysmal dilatation of the foramen ovale, satisfactory decompression may be achieved by Blalock-Hanlon atrial septectomy, open atrial septectomy, or, possibly, balloon septostomy.

Cardiac Catheterization↗
PubMed1976

Variation in the size and distensibility of the pulmonary arteries in d-transposition of the great arteries.

The relative size of the main pulmonary artery was determined from cineangiograms of 117 patients with d-transposition of the great arteries by calculating the ration between the diameters of the main pulmonary artery and aorta. The pulmonary artery was largest in patients with ventricular septal defect or patent ductus arteriosus, or both, because of increased pulmonary arterial pressure and flow. In patients with an intact ventricular septum or with left ventricular outflow tract obstruction, or both, the main pulmonary artery was approximately the size of the aorta. Two cases of d-transposition and gross dilatation of the main pulmonary artery and hypoplastic first branch pulmonary arteries are presented. In these cases the ratio between the diameters of the main pulmonary artery and aorta was greater than in any of the other 117 cases studied...

Blood Pressure↗
PubMed1976

Congenital paroxysmal atrial tachycardia.

Ten infants who had paroxysmal atrial tachycardia in utero or at birth are reported. Because of apparent fetal distress, caesarean section was performed in 4 cases and labour was induced in 1. Birthweight was generally large for gestational age. Severe ascites and hydrops at birth were manifestations of cardiac failure. Atrial flutter was recorded in 4 infants and supraventricular tachycardia in 5. The WoLff-Parkinson-White syndrome became evident later in 2. Digoxin was given to all 10 infants, and cardioversion was required and was effective in 4. Known recurrences in childhood have occurred in only 1 patient. Congenital atrial tachyarrhythmias may be commoner than generally believed, and fetal electrocardiography may help to avoid unnecessary termination of pregnancy. Blood sugar determinations are important, since neonatal hypoglycaemia was found. Cardioversion should be performed promptly in severely ill infants or if there is no response to digoxin. Care is required to avoid digoxin toxicity.

Birth Weight↗
PubMed1976

Anatomical variants in aortic atresia. Potential candidates for ventriculoaortic reconstitution.

Aortic valve atresia is usually associated with severe hypoplasia of the left ventricle and mitral apparatus. Palliative procedures, including atrial septectomy, pulmonary artery-aorta anastomosis, and pulmonary artery banding, have been performed in some patients. However, because of the distinct underdevelopment of the left heart, the long-term prognosis must be guarded even in the survivors of these procedures. Rarely, aortic valve atresia is found with adequate left heart chambers. Because very few of these patients are described, the clinical, angiocardiographic, and the pathological findings in two patients are presented, with comments on palliation in the neonatal period, and the potential for ventriculoaortic reconstitution.

Aortic Valve↗
PubMed1976

Surgical treatment of pulmonary atresia with intact ventricular septum.

Fifty-nine children with pulmonary atresia and intact ventricular septum underwent various forms of surgical treatment at the Hospital for Sick Children, Toronto, during 1950 to mid 1975. Twenty-three patients had pulmonary valvotomy, 15 direct, 2 indirect, and 6 both direct valvotomy and infundibulectomy. All died, 19 early and 4 late. Of 13 patients who received a systemic-pulmonary artery shunt, 4 combined with surgical atrial septectomy, there are only 2 long-term survivors both of whom were children who had had a Waterston anastomosis. Recently we have been treating infants with small right ventricles with balloon atrial septostomy at cardiac catherterization followed by a Potts anastomosis and pulmonary valvotomy. If the Potts anastomosis appears satisfactory the persistent ductus arteriosus is ligated. This scheme was used in 23 infants, with 4 early deaths and 2 late deaths. Of 17 survivors, further shunts were required in 4 children. One child has had a formal repair, with insertion of valves in both tricuspid and pulmonary areas. We believe that this operative combination of Potts anastomosis and pulmonary valvotomy offers the infant with pulmonary atresia and a small right ventricle a relatively low initial mortality and the possibility of right ventricular enlargement and subsequent repair.

Ductus Arteriosus, Patent↗
PubMed1976

Echocardiographic assessment of bicuspid aortic valves. Angiographic and pathological correlates.

Aortic root echocardiograms were recorded from 89 patients whose aortic valves had also been adequately defined by selective angiography or viewed surgically or at autopsy. The eccentricity index (E.I.) of the aortic leaflets was measured at the onset of diastole and an E.I. of 1.3 or greater was taken as abnormal. Of 31 patients with isolated nonobstruced or mildly obstructed bicuspid aortic valves (7 viewed previously at valvotomy and 24 diagnosed radiologically) 23 (74%) had an abnormal E.I. Varying eccentricity occurred in some of these patients. Central leaflet echoes (E.I. of 1.0 to 1.25) were present in the other eight patients. All 14 patients with nonobstructed tricuspid aortic valves had central echoes. Additional multilayered diastolic echoes were found in patients with bicuspid aortic valves as well as in two patients with abnormal tricuspid aortic valves. The valves of 13 patients with aortic stenosis or incompetence were viewed surgically and the E.I. was abnormal in all patients with a bicuspid aortic valve in this group. Aortic leaflet echo findings were not diagnostically helpful in ten patients with tetralogy of Fallot, one of whom had a normal E.I. with a surgically confirmed bicuspid aortic valve. Of 21 patients with VSD only one had a bicuspid aortic valve but six had an abnormal E.I. This false positive sign was related to a high membranous VSD, sometimes with aortic valve prolapse. It is concluded that an E.I. of greater than or equal to 1.3 in the absence of an associated VSD is diagnostic of a bicuspid aortic valve and can be expected to be found in approximately three-quarters of subjects with this abnormality.

Adolescent↗
PubMed1975

Evaluation of late results of surgical treatment of congenital heart disease.

Operative mortality from surgical treatment of congenital heart disease has been steadily reduced over the past 20 years. During the same period it has become clear that a proportion of survivors have residual clinical problems. Some of these are due to imperfect repair, a number being due to factors beyond present surgical control, and some are the consequence of associated cardiovascular defects. The chief problems can be elucidated by an analysis of the results of surgical treatment of six cardiac malformations: simple pulmonary valve stenosis, coarctation of the aorta, secundum atrial septal defect, isolated ventricular septal defect, tetralogy of Fallot and transposition of the great arteries. Recognition of the sequelae of preoperative hemodynamic strain and apparently minor associated malformations is important, and it is possible to anticipate such factors. Long-term follow-up of patients after operation is particularly important.

Adolescent↗
PubMed1975

Survival after systemic to pulmonary arterial shunts in infants less than 30 days old with obstructive lesions of the right heart chambers.

Ninety-seven infants less than 30 days old with obstructive lesions of the right heart chambers underwent palliative surgery from 1950 through 1972. The diagnosis was made at cardiac catheterization and confirmed at operation or subsequent autopsy. Because of unavailability of complete preoperative studies and sufficient blood gas data, 36 patients presenting between 1950 and 1965 (Group I) were analyzed for surgical risk only. In 61 patients who underwent palliative procedures between 1966 and 1972 (Group II) a more detailed analysis was done. In this group, 31 had a Potts shunt, 29 a Waterston shunt and 1 a Blalock-Taussig shunt. The most frequently encountered malformation was severe tetralogy of Fallot (30 percent) with or without pulmonary atresia, followed by pulmonary atresia with intact ventricular septum (25 percent). The overall surgical mortality rate in patients seen after 1965 (Group II) was 34 percent compared with the 78 percent mortality rate in patients seen earlier (Group I). The surgical mortality in infants operated on during the 1st week of life was double that of those operated on in the 2nd through 4th weeks. Survivors were compared with nonsurvivors for timing of surgery, age at presentation and clinical profile. Only two significant differences were found. Preoperative continuous murmurs were more common in those who survived operation (13 of 40 patients) than in those who died (2 of 21). Arterial pH during cardiac catheterization was the best predictor of subsequent survival, nonsurvivors having significantly greater metabolic acidosis. Palliation of these severe lesions still carries a high mortality rate to which must be added the risk of subsequent repair. Our data suggest that primary repair is to be preferred if it can be undertaken with a risk approximating that of palliative procedures.

Acidosis↗
PubMed1975

The superior QRS axis in ostium primum ASD: a proposed mechanism.

The influence of abnormal hemodynamics, ventricular hypertrophy, and right bundle branch block on the AQRS was studied pre- and post-operatively in 29 patients with OPSD. The AQRS markedly diminishes with the surgical correction of abnormal hemodynamics and the subsequent resolution of RVH or BVH. With the persistence of ventricular hypertrophy postoperatively or the surgical induction of RBBB, the AQRS either remains unchanged or, in the latter instance, becomes more superior and rightward. The dependence of the superior AQRS on these factors suggests that a left anterior hemiblock is not responsible for this AQRS. In OPSD early activation of the posterobasal region of the left ventricle through an abnormally short posterior fascicle results in a minimal superior AQRS which is then exaggerated in the presence of abnormal hemodynamics, ventricular hypertrophy, or RBBB. Thus, the superior AQRS in OPSD with associated RBBB does not represent a true bifascicular block and has a different natural history and clinical significance.

Adolescent↗
PubMed1975

Regional differences in fatty acid oxidation by the adult rabbit myocardium.

Differences in coronary perfusion and tissue oxygenation between the epicardium and endocardium have been shown. Thus, intrinsic capacity for substrate oxidation may also exhibit regional variation. Accordingly, homogenates of left ventricular papillary muscle ("endocardium") and left ventricular free wall trimmed of endocardium ("epicardium") were compared for their capacity to oxidize palmitic acid-1-14C (PA) and octanoic acid-1-14C (OcA). Homogenates from one to three rabbits were combined for each study; 18 studies were performed using PA, and 10 using OcA. The protein content of endo- and epicardial homogenates was the same (Biuret method). At ambient PA concentrations of 0.2 mM, oxidation of PA by "endocardium" was 64 +/- 6.3% that of the "epicardium" (p less than 0.001). At ambient concentrations of 1.0 mM, oxidation of OcA by "endocardium" was not different from that of "epicardium" (118 +/- 10.5%; p greater than 0.1). Thus, the oxidative capacity for long chain FFA by the endo- and epicardial homogenates are at variance. Differences in carnitine-mediated transmitochondrial transport of long chain fatty acids may be the explanation. Such regional metabolic differences could play a role in regional alterations in myocardial function under adverse hemodynamic and metabolic circumstances.

Animals↗