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Biomedical subjects

R Radley-Smith

Publications and source records attributed to R Radley-Smith.

At least 55 records · Page 3Linked to original sources
PubMed1985

Influence of the two-stage anatomic correction of simple transposition of the great arteries on left ventricular function.

To evaluate the influence of the 2-stage anatomic correction of simple transposition of the great arteries on left ventricular (LV) function, pressure and angiocardiographic volume data were analyzed during resting conditions shortly before banding of the pulmonary trunk (n = 12) and before (n = 17) and after anatomic correction (n = 11), and compared with data from controls (n = 12). Age at banding and anatomic correction was between 1 and 44 months (mean 16 +/- 10) and between 13 and 47 months (mean 24 +/- 10), respectively. The interval between anatomic correction and the investigation ranged from 10 to 29 months (mean 20 +/- 7). After banding, LV ejection fraction decreased (p less than 0.01) and LV peak systolic pressure (p less than 0.01) as well as LV end-diastolic pressure (p less than 0.05) increased. After anatomic correction, these variables and LV end-systolic wall stress were not significantly different from control values. The LV end-systolic wall stress-ejection fraction relation in 7 of 11 patients after anatomic correction was within control range. The highest values were found in the youngest patients at banding and at anatomic correction. In contrast to measures of global myocardial function, such as LV ejection fraction and LV end-diastolic pressure data, the LV end-systolic stress-ejection fraction relation suggest that LV function may not be normal in some patients 20 months after anatomic correction. Young age at operation, however, appears to be advantageous in preserving LV function. Hemodynamic alterations after banding probably reflect LV adaptation to systemic pressures in a hypoxemic circulation.

Age Factors↗
PubMed1985

Cardiac transplantation--the London experience.

One hundred and forty-eight patients have undergone cardiac transplantation at Harefield Hospital since February 1980. The first 39 patients received an immunosuppressive regime of Azathioprine and oral steroids, resulting in a high incidence of infection and a survival rate at one year of 50%. Since September 1982, a combination of Azathioprine/Cyclosporine with minimal or no steroids has been employed. There have been 28 deaths in patients on the latter regime, resulting in an 82% survival rate at one year. Infection has been significantly reduced and 97% of rejection episodes have been successfully treated. Three patients have developed lymphoproliferative disease resolving on a reduction of immunosuppression. To date, there has been no evidence of chronic rejection in these patients. The elimination of oral steroids has improved both the survival and quality of life of patients after cardiac transplantation and may enable the scope of patients considered for transplantation to be widened.

Adolescent↗
PubMed1985

[Echocardiographic pressure-dimension analysis following anatomically corrective operation of d-transposition of the great arteries].

The major theoretical advantage of anatomic correction of transposition of the great arteries compared with intraatrial repair is that the left ventricle becomes the systemic pump. In 10 patients we analysed 5-12 months after anatomic correction the left ventricular echocardiographic pressure-dimension loop, meridional wall stress and left ventricular stiffness from the simultaneous recordings of the left ventricular pressure and M-mode echocardiogram. The low left ventricular diameters, left ventricular hypertrophy in 4 patients, and increased peak meridional wall stress in 3 patients indicate that left ventricular adaption to systemic impedance is still incomplete 5-12 months after anatomic correction. The cycle efficiency was reduced in 2 patients, indicating incoordinate left ventricular contraction and relaxation. In one of these patients the left ventricular stiffness was severely increased, while in another patient there was a slight increase in left ventricular stiffness. In all patients the right ventricular internal diameter was increased due to the long-standing preoperative pressure and volume overload.

Blood Pressure↗
PubMed1985

Assessment of coronary and aortic anastomoses after anatomic correction of transposition of the great arteries.

Anatomic correction of transposition of the great arteries always entails circumferential anastomoses of the aorta and coronary arteries. Long-term success of this procedure is predicted on adequate growth of these anastomotic sites. To assess the size of these arteries, we performed one or two cardiac catheterization on 25 children from 1 to 53 months (mean 18.8 months) following anatomic correction. Early studies (mean 12 months) were performed in 23 patients and late studies (mean 30 months) in 13 patients. Age at repair ranged from 2 to 168 months (mean 25.5 months) and 15 patients were less than a year of age. Fifteen patients had undergone previous pulmonary artery banding in preparation for anatomic repair. Postoperative catheterizations showed no area of narrowing at the aortic or coronary anastomoses and no kinking of the proximal coronary arteries. Almost all normalized diameters of the aortic root were larger than normal. There were no differences between early and late measurements after anatomic correction. No patient had a pressure gradient across the aortic anastomosis. It is, therefore, concluded that the coronary and aortic anastomoses allow for satisfactory growth even when there has been previous pulmonary artery banding.

Aorta, Thoracic↗
PubMed1984

Assessment of left ventricular contractile state after anatomic correction of transposition of the great arteries.

When compared with intra-atrial baffle repairs for D-transposition of the great arteries (TGA), anatomic correction offers the theoretic advantage that it results in the use of the left ventricle (LV) as the systemic ventricle. Although the long-term success of this procedure depends on the function of the LV, little is known regarding LV postoperative contractile state. The LV end-systolic pressure-dimension and wall stress-shortening (% delta D) relationships, sensitive indexes of contractility, were studied during methoxamine-induced increases in afterload in eight patients with TGA and intact ventricular septa and in four patients with TGA and associated lesions. The patients with TGA and intact ventricular septa underwent pulmonary artery banding when they were between the ages 0.1 and 1.1 years (mean 0.4) to prepare the LV for anatomic correction. Age at repair ranged from 0.3 to 1.8 years (mean 1.0) and that at study from 1.7 to 6.7 years (mean 3.3). The interval from correction to study was 0.4 to 4.8 years (mean 2.3). End-systolic pressure was estimated from a calibrated suprasternal notch tracing. End-systolic dimension, wall thickness, and % delta D were determined by M mode and two-dimensional echocardiography, and end-systolic wall stress was then calculated. Results were compared with previously reported normal values. The pressure-dimension and wall stress-% delta D relationships were normal in 10 of 12 TGA patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗
PubMed1984

Influence of two-stage anatomic correction on size and distensibility of the anatomic pulmonary/functional aortic root in patients with simple transposition of the great arteries.

To evaluate the results of the two-stage anatomic correction of simple transposition of the great arteries the size, distensibility, and histologic characteristics of the anatomic pulmonary root, which arises from the anatomic left ventricle and which we termed the functional aortic root after anatomic correction, were determined in seven patients before and twice after anatomic correction (mean 43 and 671 days) and the results were compared with those in normal control subjects. The diameter of the systolic sinus of the anatomic pulmonary root increased after banding on the average to 140% of normal, whereas the diameter of the diastolic sinus of the functional aortic root increased after anatomic correction on the average to 150% of normal. Diameters of both the systolic and diastolic sinuses of the functional aortic root remained 30% to 55% larger than normal after anatomic correction. Growth potential of the functional aortic root after anatomic correction was normal, whereas its distensibility, as assessed by determination of the percent change in radius and pressure-strain elastic modulus (stiffness index), was decreased after anatomic correction. This pressure-strain elastic modulus was directly related to the corresponding body surface area and age at banding. In four of five specimens of the anatomic pulmonary arterial wall that were obtained at the time of anatomic correction, fragmentation and shortening of elastic fibers were observed. The histologic characteristics of the pulmonary root in the patient with the smallest body surface area at banding and normal distensibility of the anatomic pulmonary/functional aortic root before and after anatomic correction revealed normal aortic configuration of the elastic tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Aorta↗
PubMed1984

Anatomic correction of the Taussig-Bing anomaly.

Anatomic correction of the Taussig-Bing anomaly depends on thorough understanding of the variable interrelations between the atrioventricular valves, ventricular septal defect, infundibular muscle bands, and aortic and pulmonary outflows and the resulting haemodynamic changes. Depending on the relative position of the great arteries, two clinicopathological types have been identified. In the two patients with side-by-side relationship of the great arteries, the conal septum was well developed, so that there were various degrees of subaortic stenosis. Associated coarctation of the aorta was present in both patients. Coronary anatomy was identical (Type E) to that present in complete transposition with side-by-side great arteries. In these patients, anatomic correction was achieved by wide excision of the conal septum and intraventricular repair. In contrast, two patients with anteroposterior relationship of the great arteries had a poorly developed conal septum and no subaortic stenosis or coarctation of the aorta. In these patients, repair was achieved by diverting blood from the ventricular septal defect to the adjoining pulmonary artery combined with switching of the great arteries and coronary transfer. There were no early or late deaths associated with either method of repair, and there was evidence of good correction of the hemodynamic abnormalities. It is concluded that anatomic correction is possible in all patients with the Taussig-Bing anomaly and that the method of repair depends on the relative position of the great arteries.

Aorta↗
PubMed1984

Patient status 10 or more years after 'fresh' homograft replacement of the aortic valve.

One hundred and forty consecutive patients from 12 to 74 years old (mean 52) who underwent isolated elective aortic valve replacement with antibiotic-sterilized homografts have been followed for 10 to 13 (mean 11) years. There were four (2.9%) early and 48 (34.3%) late deaths. The overall survival rate was 81% at 5 years and 65% at 10 years. Valve failure occurred in 37 (26.4%) patients and was due to degeneration in 27 (19.3%), technical failure in three (2.1%), and endocarditis in seven (5%). Freedom from valve failure was 90% at 5 years and 72% at 10 years; the mean rate of valve degeneration was 1% per year up to 5 years, 2% from 5 to 8 years, and 5% from 8 to 10 years. Functional evaluation of the patients retaining their original homograft at 10 years showed excellent or good results in 82% and fair or poor results in 18%. A multivariate regression analysis of factors influencing survival and valve failure showed that older age of the patient (p less than .01) and the development of postoperative left bundle branch block (p less than .05) adversely affected survival, and that older age and sex (female) of the patient (p less than .01), the type of original valve lesion (stenosis) (p less than .05), and the interval between death and dissection of the grafts (p less than .01) were good predictors of valve failure.

Adolescent↗
PubMed1983

Catheter evaluation of left ventricular shape and function 1 or more years after anatomic correction of transposition of the great arteries.

Twenty-eight children were reinvestigated by cardiac catheterization and angiography greater than 1 year after anatomic correction of transposition of the great arteries (TGA). Seventeen patients with simple TGA underwent banding of the pulmonary trunk plus or minus systemic to pulmonary artery shunt to prepare the left ventricle for anatomic correction. In addition to TGA, 10 of the remaining 11 patients had a large ventricular septal defect and 1 had an aorticopulmonary window. They required no preparation of the left ventricle. Age at repair ranged from 2 to 120 months (mean 26). Catheterization 12 to 48 months after anatomic repair revealed a left ventricular end-diastolic pressure of 4 to 14 mm Hg (mean 9.5 +/- 2.5 [+/- standard deviation]). Ejection fraction ranged from 52 to 75% (mean 66 +/- 8). Frame-by-frame computer-assisted analysis of left ventricular (LV) contraction and relaxation was performed in 14 patients and compared with normal left ventriculograms. Shape index, derived as 4 pi X cavity area/perimeter2 X 100, was measured in 24 patients and showed a mean index of 89 +/- 3% at end-diastole and 79 +/- 8% at end-systole. A control group had a mean diastolic index of 86 +/- 6% and mean systolic index of 73 +/- 8%. It is concluded that LV shape after anatomic correction tends to be more globular than normal and changes little during systole. LV ejection fraction and end-diastolic pressure are normal.

Adolescent↗
PubMed1983

Cardiac rhythm and conduction before and after anatomic correction of transposition of the great arteries.

To assess pre- and postoperative arrhythmias associated with anatomic correction of transposition of the great arteries, 34 patients had 145 standard electrocardiograms (ECGs) and 24 of these patients had 46 24-hour ECGs from 11 months before to 54 months after anatomic repair. Twenty-two patients underwent balloon atrial septostomy and 7 surgical atrial septectomy before the initial 24-hour ECG. Anatomic correction included repair of a large ventricular septal defect in 16 patients and an aortopulmonary window in 1 patient. The preoperative standard ECG showed sinus rhythm in every patient. Preoperative 24-hour tapes revealed sinus arrhythmias in 2, sinus bradycardia at a rate of less than or equal to 50 beats/min in 1, junctional rhythm in 1 and rare premature ventricular contractions (PVCs) in 1. The postoperative 24-hour ECG showed atrioventricular dissociation in 1 patient, rare premature atrial contractions in 7, rare PVCs in 8 and sinus bradycardia with junctional escape in 1. Eight patients had PVCs on the postoperative ECG that were not noted on preoperative tapes. No patient had prolonged bradycardia (less than or equal to 50 beats/min), life-threatening arrhythmias or sudden death. Except for 1 patient with atrioventricular dissociation believed to be secondary to a preventable cause, 34 patients followed for 890 patient-months after anatomic correction for transposition of the great arteries had no significant arrhythmias.

Arrhythmias, Cardiac↗
PubMed1983

Angiographic identification of primary coronary anomalies causing impaired myocardial perfusion.

The origin and early branching of the coronary arteries is fairly constant. Anomalous origin of the coronary arteries, which produced significant abnormalities of myocardial perfusion, were documented in 13 adult patients undergoing investigation because of chest pain. All underwent surgical treatment with relief of the presenting symptoms. They can be divided into four groups: (1) Origin of the left anterior descending branch of the left coronary artery (LCA) from the pulmonary artery (PA) (three cases); (2) origin of the LCA from the anterior sinus. Acute angulation of the ostium and compression of the intramural segment of this coronary produced severe myocardial ischaemia in three patients. (3) Origin of the LCA from the right coronary artery with its proximal segment closely related to the noncoronary sinus (one patient) in whom relief of symptoms was obtained by surgery. (4) Origin of the LCA from the PA with reversal of coronary flow and left to right shunting (six patients). It is concluded that anomalies of the origin of the coronary arteries are rare, but can produce specific clinicopathological entities that can be diagnosed with confidence and corrected surgically. Moreover, the study emphasises the need for angiographic awareness of these coronary anomalies, even in adult patients in whom atherosclerotic disease would be the most likely finding at cardiac catheterisation.

Adolescent↗
PubMed1983

Fate of dynamic left ventricular outflow tract obstruction after anatomic correction of transposition of the great arteries.

Fourteen patients undergoing successful anatomic correction for transposition of the great arteries had subpulmonary gradients of 20 to 120 mm Hg (mean 40) across the left ventricular outflow tract before surgery. Ten patients had an intact ventricular septum, and four had an additional ventricular septal defect. In one patient obstruction was due to ballooning of the septal leaflet of the tricuspid valve through the ventricular septal defect. In the remaining patients obstruction was due to bulging of the interventricular septum plus or minus septal hypertrophy and with or without a fibromuscular shelf. At operation the pulmonary valve was normal and the left ventricular outflow tract was of adequate dimension with no organic obstruction. No attempt at surgical widening was made. After surgery abnormalities revealed by echocardiography were immediately reversed. Routine reinvestigation 6 to 26 months after surgery in 10 patients showed no gradient across the left ventricular outflow tract and normal development of this region.

Child↗
PubMed1982

Clinical and hemodynamic significance of anomalous origin of the right coronary artery from the pulmonary artery.

Anomalous origin of the right coronary artery (RCA) from the pulmonary artery (PA) is very rare, and may be an isolated defect, or associated with other congenital cardiac or non-cardiac defects. The anomalous right coronary artery may appear grossly normal if it arises near an aorto-pulmonary window, and will be perfused by oxygenated blood. However, it may be vein-like and perfused in a retrograde fashion from the left coronary artery (LCA). This was once thought to be a benign lesion, and an incidental finding during cardiac catheterization or surgical repair of the associated congenital cardiac anomaly, but, sudden cardiac deaths have been reported. Associated congenital cardiac defects reported include tetralogy of Fallot (2 cases), aorto-pulmonary window (3 cases), and atrial septal defect (1 case). Another case associated with tetralogy of Fallot is described. Surgical correction of these associated lesions should include anatomical correction of the anomalous right coronary artery.

Angiocardiography↗
PubMed1982

Open heart surgery in a patient with homozygous sickle cell disease.

A child in heart failure with homozygous sickle cell disease underwent corrective surgery on cardiopulmonary bypass. The use of early intra-operative exchange transfusion produced a rapid fall in the level of HbS. Postoperatively she developed falciparum malaria which responded to treatment. She was eventually discharged home to Nigeria 8 weeks after her operation.

Anemia, Sickle Cell↗
PubMed1982

Supravalvular pulmonary stenosis after anatomic correction of transposition of the great arteries: causes and prevention.

Twenty-two patients who underwent anatomic correction of transposition of the great arteries at the arterial level at the age of 8 weeks to 14 years were reinvestigated 1-4.6 years (mean 2.0 years) after operation. A Dacron tube was used to bridge the gap between the proximal pulmonary route and the distal pulmonary artery in four patients and a tube made of homologous dura mater (2.5 cm in diameter) was used in 18. The nonvalved conduit was placed on the right side of the ascending aorta in nine patients and on the left side in 13. Supravalvular pulmonary stenosis with a gradient of 45-95 mm Hg was found in three patients, all of whom had had the conduit placed on the right side. There was normal growth of the pulmonary artery proximal and distal to the stenotic area. Operation for the relief of the stenosis with insertion of a pericardial patch across the stenosed area was performed in two patients. We conclude that supravalvular pulmonary stenosis after anatomic correction of transposition of the great arteries occurs only when the new pulmonary artery is placed on the right side of the ascending aorta and that the use of a large tube of dura mater appears to allow for rapid growth in early life.

Adolescent↗