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Biomedical subjects

C N Barnard

Publications and source records attributed to C N Barnard.

At least 19 recordsLinked to original sources
PubMed1992

Long-term results of the Ivalon baffle mitral valve repair.

In the evolution of mitral valve surgery, Ivalon sponge was sutured to the posterior leaflet of the mitral valve to obtain competency. Between August 1959 and October 1962, 18 patients had this procedure. All patients were discharged home. Three patients were lost to follow-up 5 to 10 years after operation. Valve replacement was necessary in 7 patients 10.4 +/- 8.5 years after repair. Bacterial endocarditis causing late death occurred in 5 patients within 4 years. Five embolic episodes occurred. The estimated probability of survival and need for valve replacement at 28 years were 29.2% +/- 12.3% and 12.4% +/- 6.7%, respectively.

Adolescent↗
PubMed1985

Further cardiac transplant procedures in patients with heterotopic heart transplants.

Seven patients with heterotopic heart transplants have undergone further heart transplant procedures. In 5, the first heterotopically placed donor heart was excised and replaced with the second donor heart. In 2, the first heterotopic donor heart was left in situ and the patient's own heart (then nonfunctioning) was excised and replaced by the second donor heart; thus, these patients underwent orthotopic transplantation and were left with two donor hearts. The decision to perform retransplantation in a patient undergoing irreversible acute rejection is usually straightforward, but the timing of a further transplant procedure in a patient with advanced graft arteriosclerosis may present a difficult problem. Two of the 7 patients in this series died of infectious complications within the first 3 months after retransplantation. A third patient acutely rejected the second donor heart within 5 days, but survived an additional 17 months with the support of his own cardiomyopathic heart. Four patients remain alive and well between 5 and 36 months following the second transplant and between 17 and 54 months following the first transplant procedure.

Acute Disease↗
PubMed1985

The significance of left ventricular volume measurement after heart transplantation using radionuclide techniques.

Multigated equilibrium blood pool scanning using Technetium 99m labeled red blood cells was used to measure left ventricular volumes in three heterotopic and one orthotopic heart transplant recipient(s). Simultaneously, an endomyocardial biopsy was performed and the degree of acute rejection was assessed by a histological scoring system. The scores were correlated to changes in ejection fraction and heart rate. Technetium 99m scanning data were pooled according to the endomyocardial biopsy score: no rejection; mild rejection; moderate rejection, and severe rejection. In each group, the median of the left ventricular volume parameters was calculated and correlated with the endomyocardial biopsy score, using a non-parametric one-way analysis of variance. A decrease in stroke volume correlated best with the endomyocardial biopsy score during acute rejection. A decrease in end-diastolic left ventricular volumes did not correlate as well. Changes in the end-systolic left ventricular volumes were not statistically significant, but using a simple correlation between end-systolic left ventricular volumes and endomyocardial biopsy the correlation reached significance. Changes in left ventricular volumes measured by Technetium 99m scanning may be useful to confirm the presence or absence of acute rejection in patients with heart grafts.

Adolescent↗
PubMed1984

Surgical management of congenital heart disease. A review of 7 years' experience.

This is a review of the results of surgical treatment of congenital heart disease in children aged less than 12 years over the period 1975 - 1981 (1254 cases). The patients are divided into two groups, those treated between 1975 and 1979 (903 cases) and those treated in 1980 and 1981 (351 cases). Only 19,7% of the patients in the first group were under the age of 1 year, but 26,5% in the second group were in this age group. This reflects a change in policy and an attempt at surgical correction at a much younger age than was previously the case. Our present policy in cardiac emergencies in infants will be discussed. Despite the higher percentage of infants aged under 1 year who were treated in 1980 - 1981, the mortality rate was lower than that for the period 1975 - 1979. This probably reflects greater experience in the post-operative management of patients under the age of 1 year.

Age Factors↗
PubMed1984

Primary cardiac haemangiomas. A report of 2 cases.

Primary heart tumours are extremely rare. Over a period of 25 years 22 primary cardiac tumours were diagnosed clinically or at autopsy at Groote Schuur Hospital. Fourteen patients with myxomas, 1 with lymphocytic lymphoma and 2 with haemangiomas underwent surgery. A further 4 myxomas and 1 histiocytoma were found at autopsy. In both the cases of haemangioma the diagnosis of a vascular tumour was made before surgery. One tumour had infiltrated the lateral wall of the left ventricle and was unresectable; only a biopsy specimen was taken. The patient, however, remains well some 6 years later. In the second patient the haemangioma was situated in the outflow tract of the right ventricle and was successfully excised. The clinical history, pathological features and management of both cases are presented.

Child, Preschool↗
PubMed1984

The significance of femoral pulses in coarctation of the aorta.

Between January 1974 and December 1981, 80 patients aged between 1 and 13 years underwent surgical correction of coarctation of the aorta. At pre-operative examination 45 patients had absent femoral pulses (group A) and 35 had palpable femoral pulses (group B). Nineteen patients were lost to late follow-up; the remaining 61 (76%) were followed up for between 3 months and 7 years. Of the patients in group A 89% had systolic and 87% diastolic hypertension, while in group B the respective figures were 80% and 77%. At follow-up after surgery, systolic hypertension was present in 36% of patients in group A and in 16% of those in group B. Diastolic hypertension was present in 73% of patients in group A but only in 19% of those in group B (P less than 0,0001). It would appear that children with coarctation of the aorta and absent femoral pulses are more likely to continue to have diastolic hypertension after surgical correction of the anomaly than are children in whom the femoral pulses are palpable. Early operation might reduce the incidence of hypertension in this group.

Adolescent↗
PubMed1984

Heterotopic cardiac transplantation. A 7-year experience at Groote Schuur Hospital, Cape Town.

Between November 1974 and February 1982 40 patients underwent heterotopic heart transplantation at Groote Schuur Hospital, Cape Town. In 4 of these patients retransplantation was carried out, bringing the total number of heterotopic heart transplant operations to 44. Fourteen patients are alive to date, from 4 months to more than 7 years after transplantation. The 1-year survival rate has been 60%. Three of the first 6 patients in this series have survived for 6 years or more, while 6 of the 7 patients who received transplants during 1981 (including 2 who underwent retransplantation) are alive. Retransplantation of the donor heart, donor heart procurement from distant sources using prolonged myocardial preservation techniques and the reasons why heterotopic cardiac transplantation is more advantageous than other methods are discussed. The surgical technique and some modifications introduced since this method was first described in 1975 are presented in detail.

Adolescent↗
PubMed1984

Valve replacement in patients over 70 years of age.

Between 1 August 1975 and 31 October 1982, 76 patients aged between 70 and 82 years (mean 73,4 years) underwent elective (71) or emergency (5) valve replacements. Fifty patients underwent aortic valve replacement (including 5 with additional coronary artery bypass grafts), 19 mitral valve replacement including 3 with coronary artery bypass grafts, and 7 double valve replacements. There were 3 early deaths (3,9%) and 9 late deaths (11,8%) during the follow-up periods of 1 month - 86 months (mean 29 months). Actuarial analysis showed a survival rate of 95% at 1 year, 89% at 2 years, and 77% at 5 years. The clinical result of operation was judged to be good or excellent in all patients except one. It is concluded that valve replacement in patients over 70 years carries a low operative risk, statistically similar to that for younger patients at our institution, and is accompanied by a satisfactory result.

Age Factors↗
PubMed1984

Prediction of acute cardiac rejection using radionuclide techniques.

Radionuclide scanning of the donor left ventricle using technetium-99m-labelled red cells was used to monitor acute rejection after heterotopic heart transplantation and compared with histopathological evidence of rejection obtained at examination of an endomyocardial biopsy specimen. The ejection fraction and end-diastolic, end-systolic and stroke volumes were calculated at each examination; an equation was derived from these data to predict the degree of acute rejection, using histopathological examination of endomyocardial biopsy specimens as criteria of the presence and severity of rejection. A highly significant multiple correlation between radionuclide scanning parameters and endomyocardial biopsy was found. The advantages of non-invasive radionuclide scanning over the invasive procedure of endomyocardial biopsy are discussed.

Adolescent↗
PubMed1984

Comparison of patients with ischemic, myopathic, and rheumatic heart diseases as cardiac transplant recipients.

Fifty-four human-to-human cardiac transplants (10 orthotopic and 44 heterotopic) in 50 patients were performed between December, 1967, and December, 1981. The underlying cardiac pathology was ischemic (IHD) in 29, cardiomyopathic (CM) in 17, rheumatic (RHD) in four, and mixed or other pathology in four. Patients with RHD survived for a mean period over three times as long as those with either CM (p less than 0.02) or IHD (p less than 0.05). Although CM patients were on average over a decade younger than those in other groups, they had a lower survival rate. There was a higher incidence of death from chronic rejection in patients with IHD, in whom there was also a higher incidence of thromboembolic episodes. Major infections were over twice as frequent in IHD patients as in CM patients (p less than 0.01). Noncompliance with regard to adherence to instructions and therapy was a significant factor in morbidity and mortality, especially in CM patients. Our data suggest that survival and morbidity of recipients of heart transplants might be influenced to some extent by the nature of the underlying primary cardiac condition, RHD being considered a favorable survival factor when compared with IHD, and CM being particularly unfavorable.

Adult↗
PubMed1984

Lack of efficacy of high-dose verapamil in preventing brain damage in baboons and pigs after prolonged partial cerebral ischemia.

There has been mounting speculation that calcium antagonists may be useful in reducing or preventing brain damage after cardiopulmonary resuscitation. To test the clinical usefulness of these agents in averting such damage, high-dose verapamil was administered to baboons and pigs after partial cerebral ischemia for varying periods of time. In Group A baboons and pigs, the major aortic branches supplying the carotid and vertebral circulations were clamped for periods ranging from 15 to 150 minutes, and neurological recovery was observed. In Group B, verapamil hydrochloride 0.7 mg/kg was given by intravenous infusion after similar periods of arterial occlusion. The administration of verapamil did not lead to any clinically improved neurological outcome. The use of verapamil after prolonged periods of partial cerebral ischemia did not improve neurological recovery in baboons and pigs.

Animals↗
PubMed1984

Cardiac transplantation following storage of the donor heart by a portable hypothermic perfusion system.

Four patients have undergone heterotopic heart transplantation with donor hearts stored by a portable hypothermic perfusion system. Total ischemic periods ranged from 6 hours 55 minutes to 16 hours 50 minutes. One heart, transplanted into a patient who had acutely rejected a previous graft, suffered accelerated, irreversible, acute rejection within five days, associated with strong antibody formation; donor heart function was never good. In the 3 remaining patients, donor heart function was good after initially being poor for a few hours in 2 patients. One patient died of long-term rejection after 6 months and 1 of tuberculous meningitis after 10 months; 1 remains alive at 15 months. Neither preservation of the donor heart for periods in excess of approximately 4 hours nor the use of continuous hypothermic perfusion as a method of preservation appears to have been reported previously in the context of the clinical situation.

Adult↗
PubMed1984

The surgical treatment of tetralogy of Fallot.

This is a review of the last 307 patients with tetralogy of Fallot who were operated on in our unit at Groote Schuur Hospital and Red Cross War Memorial Children's Hospital. Complete repair was undertaken in 301 patients, and shunts were performed in 6 children. There were 17 hospital deaths and 1 late death. The mortality was 5.5% for children less than 12 years old and 6.6% in patients between 12 and 20 years old. During this study period, there was a change in our policy as to when complete repair should be attempted. At present, we perform systemic-pulmonary shunts in patients less than 6 months old and delay complete repair until the child is 2 years old. In deciding whether a shunt should precede complete repair, our experience has shown that age is not as important a consideration as the anatomy of the outflow tract of the right ventricle and pulmonary arteries.

Adolescent↗