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Biomedical subjects

O Geiran

Publications and source records attributed to O Geiran.

At least 37 records · Page 2Linked to original sources
PubMed1997

Hypertension prophylaxis with omega-3 fatty acids in heart transplant recipients.

OBJECTIVES: This study sought to determine whether omega-3 fatty acids act as hypertension prophylaxis in heart transplant recipients and have an impact on vascular reactivity. BACKGROUND: Cyclosporine-induced hypertension is probably related to endothelial dysfunction. Suggested vasodilatory mechanisms of omega-3 fatty acids may therefore be particularly beneficial in heart transplant recipients. METHODS: Heart transplant recipients were randomized to receive either 4 g of omega-3 fatty acids (treatment group, n = 14) daily or corn oil (placebo group, n = 14) from the fourth postoperative day. Twenty-four hour blood pressure monitoring was performed at day 12 and 1,2,3 and 6 months postoperatively. Microvascular endothelium-dependent vasodilation, evaluated by skin laser Doppler perfusion measurements of postocclusive reactive hyperemia, was determined preoperatively and at the end of the study. RESULTS: With comparable characteristics at the time of randomization, blood levels of cyclosporine did not at any point differ between the groups. After 6 months, systolic blood pressure decreased 2 +/- 4 mm Hg (mean +/- SEM) in the treatment group and increased 17 +/- 4 mm Hg in the placebo group (p < 0.01), whereas diastolic blood pressure increased 10 +/- 3 and 21 +/- 2 mm Hg (p < 0.01), respectively. The decrease in systolic blood pressure was inversely proportional to increases in concentrations of serum eicosapentaenoic and docosahexaenoic acid (p = 0.01). After 6 months, five patients in the treatment group and nine in the placebo group needed additional antihypertensive treatment. Although the endothelial-dependent phase of the reactive hyperemic response remained unchanged in the treatment group, it decreased significantly in the placebo group. CONCLUSIONS: Postoperative daily administration of 4 g of omega-3 fatty acids in heart transplant recipients is effective as hypertension prophylaxis, depending on increases in serum eicosapentaenoic and docosahexaenoic acids. Preservation of microvascular endothelial function, demonstrated by a more pronounced response to forearm skin ischemia in the treatment group, may contribute to the hypotensive role of omega-3 fatty acids.

Blood Pressure↗
PubMed1997

Post-transplant hyperlipidaemia: low-dose lovastatin lowers atherogenic lipids without plasma accumulation of lovastatin.

OBJECTIVES: The purpose of the present study was twofold. First, to determine the frequency of hyperlipidaemia after heart transplantation (Tx) in relation to values obtained before Tx. Secondly, to examine the effect of low-dose lovastatin on possible antiatherogenic mechanisms and test the hypothesis that the side-effects are dose-dependent. SUBJECTS AND DESIGN: Retrospective study of the frequency of hyperlipidaemia disturbances in heart transplant patients. In addition, in a prospective study, the safety and efficacy of incremental low doses of lovastatin up to 20 mg day-1 were studied, with measurements of its plasma concentration in 24 cyclosporin A treated heart (n = 14) and kidney (n = 10) recipients with total cholesterol > 7.5 mmol L-1. RESULTS: Cholesterol increased markedly after heart transplantation from a pretransplant value of 5.3 (5.0,5.6) mmol L-1 to 6.7 (6.4,7.0) mmol L-1 after 1 year and then remained constant, but this increase was largely due to a 'normalization' since cholesterol decreased significantly during increasing heart failure before transplantation. Treatment with lovastatin decreased total cholesterol by 19% (P < 0.001), primarily by an effect on LDL cholesterol. HDL cholesterol increased by 15% (P < 0.05), whereas triglycerides remained unchanged. Lovastatin also caused a significant reduction in apolipoprotein B of 16%, and lipid peroxidation of 40%, whereas apolipoprotein A-I, fibrinogen, and glycerol were unchanged. Plasma concentration of lovastatin was significantly higher in transplant recipients compared with controls, but there was no accumulation during incremental dosing of lovastatin. The drug was well tolerated without significant symptoms or evidence of myopathy. CONCLUSIONS: Hyperlipidaemia is common after cardiac transplantation. Treatment with low dose lovastatin is well tolerated and has a favourable effect on atherogenic lipids.

Adult↗
PubMed1997

Percutaneous transluminal angioplasty and retransplantation due to transplant coronary artery disease.

Allograft vascular disease is a significant cause of death of cardiac transplant recipients after the first year of transplantation. With few exceptions, angina pectoris does not develop and objective examinations, including coronary angiography, are necessary to diagnose coronary arteriopathy. Between 1983 and 1994, 214 heart transplantations in 211 patients were performed in our unit. All survivors had coronary angiography performed yearly. Thirty patients had significant localized arterial stenoses. Twelve patients with critical stenosis were accepted for percutaneous transluminal coronary angioplasty. Five patients underwent retransplantation due to progressive graft vascular disease with development of congestive heart failure. Conventional revascularization with transluminal coronary angioplasty can safely be performed with primary good results. In selected patients, retransplantation is an option if patients otherwise fulfil standard criteria for cardiac transplantation.

Adolescent↗
PubMed1997

Comparison between alpha-1 adrenoceptor-mediated and beta adrenoceptor-mediated inotropic components elicited by norepinephrine in failing human ventricular muscle.

The purpose of our study was to investigate the inotropic response to the endogenous agonist norepinephrine mediated through alpha-1 adrenoceptors and to compare this response to that mediated through beta-adrenoceptors in failing human ventricular myocardium. We studied ex vivo the inotropic effect of norepinephrine in isometrically contracting trabecular myocardium from both ventricles of explanted hearts. By studying influence of appropriate adrenoceptor blockers, qualitative characteristics of the inotropic response and sensitivity of the inotropic response to cholinergic stimulation, it was revealed that norepinephrine evoked both alpha-1 and beta adrenoceptor-mediated inotropic effects in failing human ventricle myocardium. Quantitatively the inotropic responses to norepinephrine varied markedly between preparations, but the mean responses elicited through the respective adrenoceptor systems were of comparable magnitude. Concomitant stimulation of alpha-1 and beta adrenoceptors by norepinephrine alone revealed a contribution of an alpha-1 adrenoceptor-mediated component to the final and unopposed inotropic response. Differential sensitivity of the two adrenoceptor systems to norepinephrine depending on etiology of heart failure and possibly also thyroid status was observed. It is concluded that norepinephrine evokes an alpha-1 adrenoceptor-mediated inotropic effect comparable to that evoked through the beta adrenoceptors in failing human ventricular myocardium, and that this alpha-1 adrenoceptor-mediated inotropic effect may be of functional importance.

Adrenergic Antagonists↗
PubMed1996

[Heart transplantation as a life saving procedure after conventional heart surgery].

The first cardiac transplantation in Norway was performed in November 1983. At the end of 1995 the number of heart transplantations at our institution had reached 238. Five of these patients (2.1%) were transplanted in the early postoperative period of failed conventional cardiac surgery (respectively 20, 26, 54, 84, and 234 hours post surgery). The primary procedure consisted of mitral valve replacement plus left ventricular aneurysm resection, coronary artery bypass grafting, Konz-Konno procedure, aortic valve replacement, and redo coronary artery bypass grafting in patients aged 47, 54, 49, 52, and 43 years respectively. All except one were high-risk patients. All patients were on circulatory support (IABP, LVAD or ECMO) before transplantation. One patient died 12 hours after the transplant due to multiorgan failure that was not reversed by improved pump function. There was one late death four months postoperatively due to severe acute vascular rejection. Three patients are doing well respectively six years, 20 and four months after transplant. We conclude that cardiac transplantation in the early postoperative period of failed conventional heart surgery is an encouraging option in highly selected patients otherwise considered to die in a very short time.

Adult↗
PubMed1996

[Meconium ileus-equivalent in adult patients with cystic fibrosis].

Gastrointestinal complications of cystic fibrosis are becoming more common because patients with cystic fibrosis are living longer. There are 227 cystic fibrosis patients in Norway today, almost half of whom are more than 18 years old. Meconiumileus-equivalent is a complication which increases with age. It is a term used to describe partial or complete intestinal obstruction occurring in patients with cystic fibrosis. It results from abnormally viscid mucofaeculent material in the terminal ileum and right proximal colon. Some patients may experience acute complete obstruction, but most of them suffer from chronic partial obstruction, with recurring colicly abdominal pain and some distension. Of 70 adult cystic fibrosis patients at Aker hospital over a seven year period, 26% had symptoms and signs of this disorder. Conservative treatment is preferable, and surgery should be avoided.

Abdomen, Acute↗
PubMed1996

Release of soluble tumour necrosis factor alpha receptors during and after paediatric cardiopulmonary bypass. Correlation with haemodynamic and clinical variables.

The release of cytokines during cardiopulmonary bypass (CPB) may contribute to haemodynamic alternations encountered after open heart surgery. Regulatory mechanisms exist and include soluble cytokine receptors. We have measured blood levels of tumour necrosis factor (TNF) and its soluble receptor (TNFsr) during and after open heart surgery in children. Correlation analysis to haemodynamic and clinical variables was performed. Using immunoassays the authors registered a significant increase in plasma levels of TNFsr with peak levels 2 h post-operatively at a level of 1702 +/- 170 pg/ml. The concentration of TNFsr remained significantly elevated until 48 h postoperatively but TNF was not significantly elevated. An inverse correlation existed between peak TNFsr and mean arterial pressure (rho = -0.827, P < 0.05), between TNFsr and cardiac index (rho = -0.8, P < 0.05), between TNFsr and left ventricular stroke work index (rho = -0.983, P < 0.01), between TNFsr and weight (rho = -0.85, P < 0.05) and between TNFsr and body surface area (rho = -0.867, P < 0.05). The authors demonstrate that the smallest children experienced the highest TNFsr concentration post-operatively. Furthermore cardiac performance, expressed as cardiac index and left ventricular stroke work index, correlated inversely to peak TNFsr level post-operatively.

Cardiopulmonary Bypass↗
PubMed1996

HLA-DR matching reduces rejection rate in heart transplantation.

We have studied the influence of serological matching for ten HLA-DR antigens on the occurrence of acute cellular rejection in heart transplantation by correlating the findings in routine endomyocardial biopsies taken during the first posttransplant year with the results of HLA typing of all recipients of a first cardiac graft and their donors during 1983-1994 at our center. We found that recipients of HLA-DR matched hearts had a lower frequency of acute cellular rejection, especially so for the moderate/severe rejection grades. Also, rejection appeared earlier in the DR-mismatched combinations. Whether the mismatch was for one or two DR antigens did not make a significant difference, neither could we demonstrate any influence of HLA-A or -B mismatches. The survival of DR-matched cardiac grafts tended to be higher at 1 year than DR-mismatched grafts, but the difference did not reach statistical significance.

Adolescent↗
PubMed1996

Five years' follow-up of renal glomerular and tubular functions in heart transplant recipients.

BACKGROUND: Many studies have shown that cyclosporine A may have detrimental long-term effect on kidney function. However, few prospective long-term studies have assessed both glomerular and tubular functions of the kidneys in heart transplant recipients METHODS: We examined 10 heart transplant recipients prospectively for 5 years. Hemodynamic data were obtained by standard heart catheterization technique, and glomerular filtration rate and blood flow were calculated as clearance of inulin and paraaminohippuran, respectively. Tubular functions were assessed by renal excretion of enzymes and albumin and by the lithium clearance method. All patients received cyclosporine A, azathioprine, and prednisolone as immunosuppressive regimen. The dose of cyclosporine averaged 3.9 +/- 0.3 during the first year and 3.2 +/- 0.3 mg/kg up to 5 years. RESULTS: All patients completed the study. Four received rejection therapy. Six were treated for hypertension. Cardiac output remained unchanged and averaged 5.5 +/- 0.9 L/min at baseline. No change ws found in any of the measured or calculated central hemodynamic parameters except a tendency toward an increased systemic peripheral resistance with time. Glomerular filtration remained constant at 66 +/- 22 ml/min, renal plasma flow showed a tendency to decline averaging 361 +/- 133 at baseline and 254 +/- 68 ml/min at 5 years (p = 0.08). Albumin excretion rate increased from 22 +/- 27 to the 102 +/- 100 micrograms/min between 1 and 5 years ( p < 0.05). The excretion of tubular enzymes, N-acetyl-6-glucosaminidase and alkaline phosphatase, and the renal handling of lithium remained unchanged. CONCLUSIONS: Cyclosporine therapy over 5 years did not progressively impair glomerular or tubular functions. However, the occurrence of microalbuminuria may be caused by therapy with cyclosporine itself or associated hypertension.

Albuminuria↗
PubMed1996

Exercise capacity of heart transplant recipients: the importance of chronotropic incompetence.

BACKGROUND: Maximal exercise capacity is limited in patients after heart transplantation. The extent to which chronotropic incompetence contributes to this intolerance has not been well defined. METHODS: This prospective cross-sectional study examined the heart rate response to exercise and its relation to exercise capacity in 159 heart transplant recipients during progressive, symptom-limited, upright exercise. All prior exercise studies of heart transplant recipients that reported peak oxygen uptake and peak heart rate were also evaluated. RESULTS: Peak oxygen uptake was closely correlated with peak heart rate (r = 0.39, p < 0.001) and maximum increase in heart rate (r = 0.49, p < 0.001) during exercise by our patients. Similar correlations were found in the published studies for peak oxygen uptake versus maximal heart rate (r = 0.54, p < 0.05) and peak oxygen uptake versus increase in heart rate (r = 0.63, p < 0.02). The current study showed that the increase in heart rate from rest to peak exercise was significantly higher and the decline in heart rate after exercise significantly faster for patients 2 or more years after transplantation than for patients less than 2 years after transplantation (46 +/- 2 versus 38 +/- 1.9 beats/min, p < 0.05); the decline in heart rate 4 minutes after exercise was 27 +/- 1.8 versus 16 +/- 1.8 beats/min, respectively ( p < 0.001). CONCLUSION: The reduction in peak oxygen consumption, particularly during the first 2 years, appears to be related in part to chronotropic incompetence. Late after transplantation the heart rate response to exercise is greater and the decline in heart rate after exercise faster, suggesting possible autonomic reinnervation in some patients. Chronotropic incompetence may be an inadequate explanation of oxygen uptake impairment seen late after transplantation, when other factors such as myocardial dysfunction and intrinsic skeletal muscle abnormalities are of increasing importance.

Analysis of Variance↗
PubMed1995

[Treatment of terminal heart failure].

Heart transplantation is one treatment for terminal heart failure. To assure a good result it is important to give optimal treatment while waiting for a suitable donor organ. We review the treatment received by patients on the waiting list for heart transplantation at our hospital from 1983 to 1994. On the basis of our experience from 183 patients, we discuss the routine and intensive care of severe heart failure, as well as the practice of anticoagulation and antiarrhythmic treatment.

Adolescent↗
PubMed1995

[Hypercholesterolemia--a clinical problem in heart transplantation. A therapeutic trial with low-dose lovastatin].

One year after heart transplantation, serum total cholesterol had increased by 24% in 103 recipients on prednisolon, cyclosporin A, and azathioprin immuno-suppression, and was above 5.2 mmol/l in 84 of them. Incremental small dose lovastatin treatment up to 20 mg per day safely reduced total cholesterol by 19% and LDL-cholesterol by 24% in 14 patients with serum cholesterol above 7.5 mmol/l. Serum concentration of lovastatin did not increase further after three weeks treatment with 20 mg. It is concluded that hypercholesterolaemia in heart recipients treated with cyclosporin A can be treated safely with small dose lovastatin. Drug therapy should be individualized and conducted by physicians experienced in transplantation medicine.

Adult↗
PubMed1995

The CarboMedics valve: midterm follow-up with analysis of risk factors.

BACKGROUND: This study examined the midterm results with the CarboMedics prosthetic valve. METHODS: From 1987 through 1991 a total of 569 patients received the CarboMedics prosthesis. RESULTS: Early mortality was 4.9% and related to emergency operation, presence of diabetes mellitus, coronary artery disease, preoperative New York Heart Association class, duration of cardiopulmonary bypass, and aortic cross-clamp time. Midterm follow-up with respect to mortality was 100% complete. All patients were followed up in the hospital after 1 year. In addition 86% of the patients responded to a questionnaire. Mean follow-up was 3 years (range, 0 to 5.6 years). Cumulative survival at 1 and 4 years was 91.2% +/- 1.2% and 83.7% +/- 1.8%, respectively. Five patients experienced obstructive valve thrombosis (0.3%/patient-year), 16 patients had major thromboembolic events (0.9%/patient-year), and 10 patients had major warfarin-related bleeding (0.6%/patient-year) requiring hospitalization or blood transfusions. Eight patients were reoperated on for paraprosthetic leak (0.4%/patient-year). Prosthetic valve endocarditis developed in 4 patients (0.2%/patient-year). No structural valve failure was observed. CONCLUSIONS: Midterm follow-up demonstrates that the CarboMedics mechanical prosthesis is reliable and has an acceptable rate of valve-related complications.

Adolescent↗
PubMed1995

Fluid balance and pulmonary functions during and after coronary artery bypass surgery: Ringer's acetate compared with dextran, polygeline, or albumin.

The effects on fluid balance, pulmonary functions and economics were evaluated in a randomized comparison of one colloid free and three colloid containing fluid regimens, for 48 hours during and after coronary artery bypass (CAB) surgery. A standard regimen for anaesthesia, extracorporeal circulation and monitoring was used. Only Ringer's acetate (RAc) was used as priming solution for extracorporeal circulation. Forty patients were randomized to receive either RAc, polygeline 35 mg.ml-1 (Haemaccel), dextran 70 (Macrodex) 60 mg.ml-1, or albumin 40 mg.ml-1 in saline whenever fluid volume was needed to stabilize haemodynamics. At the end of the operation, fluid retention was significantly lower in patients receiving polygeline and dextran 70, compared with patients receiving RAc. At 48 hours, however, there were no differences in cumulative fluid balance. Patients in the colloid groups postoperatively had a higher serum colloid osmotic pressure (s-COP), but a higher net lung capillary filtration pressure (delta P) only on the second postoperative day than the RAc group. However, this did not adversely affect intrapulmonary venous admixture, arterial oxygen tension, or time on respirator in the RAc group compared with the colloid groups. The most expensive colloid fluid regimen (albumin) cost about 230 US$ more per patient than the RAc fluid regimen. We conclude that Ringer's acetate for volume replacement to stabilize haemodynamics during and after CAB surgery is associated with increased fluid retention only during the intraoperative period, compared with dextran 70 or polygeline, and with a lower serum colloid osmotic pressure and net lung capillary filtration pressure postoperatively, compared with all three colloid groups. This does not affect pulmonary functions adversely.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

Autotransfusion after open heart surgery: the oxygen delivery capacity of shed mediastinal blood is maintained.

Autotransfusion of mediastinal shed blood after open heart surgery has become a common and accepted procedure in reducing the need for homologous transfusion during the last 15 years. The objectives of the present study were to investigate the oxygen delivery capacity of autotransfused shed mediastinal blood, compared to patient-blood, during cardiopulmonary bypass and in the postoperative period. Ten consecutive patients undergoing elective cardiac surgery were studied. Mediastinal shed blood was collected in the cardiotomy reservoir and retransfused during the first 18 postoperative hours. The oxygen delivery capacity of the blood to the tissues was calculated by use of the oxygen status algorithm (OSA 2.0) programme and measurement of the 2,3-diphosphoglycerate (2,3-DPG) concentration. Autotransfusion volume ranged from 450-1530 ml per patient (median 824 ml). Shed blood had a mean haemoglobin level of 8.8 g/dl and 7.4 g/dl at 1 h and 6 h of autotransfusion, respectively. There were no significant changes of 2,3-DPG concentration in the patient-blood during cardiopulmonary bypass or after autotransfusion compared to preoperative values. P50 for oxygen (3.6 and 3.6 kPa) and 2,3-DPG concentrations (5.3 and 5.1 mikromol/ml erythrocyte) in shed mediastinal blood (1h and 6h postoperatively) were not significantly different compared to patient-blood. The results demonstrate that the oxygen delivery capacity of shed mediastinal blood is maintained and that the oxygen affinity of patient-blood is not influenced by autotransfusion.

2,3-Diphosphoglycerate↗
PubMed1995

Autotransfusion after open heart surgery: quality of shed mediastinal blood compared to banked blood.

The need to conserve a patient's own blood and avoid homologous transfusion is now well recognized. Therefore, techniques designed to reduce requirements for homologous blood transfusions have been developed. One of the methods is autotransfusion of shed mediastinal blood after open-heart surgery. The objectives of the present study were to investigate osmotic fragility and oxygen transport capacity of shed mediastinal blood compared to patient blood and stored packed red blood cells (SAGM). Shed mediastinal blood from ten consecutive patients undergoing elective cardiac surgery (coronary bypass grafting) was studied and compared to patient blood, 10 units of 3 weeks old and 10 units of 5 weeks old stored packed red blood cells (SAGM). Oxygen transport capacity was investigated by calculation of p50 for oxygen by use of the oxygen status algorithm (OSA 2.0) programme and measurement of 2,3-diphosphoglycerate (2,3-DPG) concentrations. The osmotic fragility was determined using increasing concentrations of saline. 2,3-DPG concentrations in shed mediastinal blood (5.3 mikromol/ml erythrocyte) were within the range measured in patient blood, but significantly higher than SAGM blood (P < 0.001). P50 for oxygen (3.5 kPa) in shed mediastinal blood was not significantly different compared to patient blood, but significantly higher (P < 0.01) compared with stored SAGM blood. The osmotic fragility in shed mediastinal blood was not significantly different compared to patient blood, but significantly lower (P < 0.001) than the osmotic fragility in stored SAGM blood. This suggests that red cells saved from shed mediastinal blood have better oxygen transport capacity and may have longer survival compared to stored blood.

Aged↗
PubMed1995

Cutaneous complications in heart transplant recipients in Norway 1983-1993.

All Norweigian heart transplant recipients with more than one year's survival (n = 140) were investigated for dermatological disorders. Observation time after transplantation was 1-10 years (mean 5.0 years). Patients alive at the end of 1993 (n = 122) were examined clinically, and medical records for all patients were reviewed. The histopathological diagnoses of excised skin specimens were reevaluated. Malignant skin tumours (i.e. basal cell carcinoma, squamous cell carcinoma and malignant melanoma) and/or premalignant skin tumours (i.e. morbus Bowen (carcinoma in situ), solar keratosis and keratoacanthoma) were found in 34 patients (24.3%), of which 18 patients (12.9%) had malignant skin tumours. Seventeen lesions diagnosed as keratoacanthoma and two lesions diagnosed as morbus Bowen had primarily been diagnosed as squamous cell carcinoma. Five patients (3.6%) had multiple keratoacanthomas. Other frequent dermatological diagnoses included hypertrichosis (86.9%), steroid-induced skin features (59.8%), common warts (42.6%) and seborrheic skin disorders (20.5%). This study demonstrates the importance of dermatological surveillance in the follow-up of heart transplant recipients.

Adolescent↗