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Biomedical subjects

H Lindberg

Publications and source records attributed to H Lindberg.

At least 19 recordsLinked to original sources
PubMed1995

Endogenous norepinephrine stimulates both alpha 1- and beta-adrenoceptors in myocardium from children with congenital heart defects.

Atrial tissue removed from the cannulation site prior to cardioplegia (n = 15), and ventricular tissue therapeutically excised from the outflow tract of the right ventricle, (RVOT) (n = 2) were examined with respect to adrenoceptor mediated inotropic effect in children with congenital heart defects (CHD). We used sequential reversal by adrenoceptor antagonists of the tyramine enhanced response to endogenous norepinephrine to quantify the role of the beta- and the alpha 1-adrenoceptors, respectively, in the intropic response. Atrial myocardium had an alpha 1-adrenoceptor mediated component of 14% (median) (range 0-44%) and a beta-adrenoceptor mediated component of 86% (median) (range 56-100%). The patients with the highest alpha 1-adrenoceptor mediated inotropic components, had right ventricular pressure loads in the systemic range. In one specimen from RVOT, the ventricular alpha 1-adrenoceptor component was estimated to be 22% of the total inotropic response, compared to 26% in the corresponding right atrium. In a ventricular specimen from another patient, we could not demonstrate any alpha 1-adrenoceptor mediated inotropic component in contrast to 13% in the right atrium. This patient, however, had infusion of the alpha-adrenoceptor antagonist phentolamine after the excision of atrial tissue, but before the excision of muscular tissue from RVOT. In myocardium of children with CHD we found evidence that endogenous norepinephrine stimulated alpha 1-adrenoceptors in addition to beta-adrenoceptors. The relative contributions from the two adrenoceptors to the inotropic response varied considerably, and may be related to the pressure load of the right ventricle. These observations may be relevant with respect both to pathophysiology and to choice of drug therapy.

Child↗
PubMed1995

Complement activation and release of tumour necrosis factor alpha, interleukin-2, interleukin-6 and soluble tumour necrosis factor and interleukin-2 receptors during and after cardiopulmonary bypass in children.

C3 activation products, terminal complement complex (TCC), and cytokines including interleukins 6 and 2 (IL-6, IL-2) and tumour necrosis factor-alpha (TNF), and the soluble IL-2 and TNF receptors were determined serially during and up to 48 h after open heart surgery in children. Significant increases were noted in soluble TNF and IL-2 receptor levels postoperatively (p < 0.05). No significant increase over preoperative levels was seen in the cytokines, except for IL-6 which was significantly increased postoperatively (p < 0.01), reaching a maximum 2 h postoperatively. C3 activation products and TCC levels increased significantly after weaning from cardiopulmonary bypass (p < 0.05). The IL-6 response lagged behind the complement activation. We found a significant correlation between duration of cardiopulmonary bypass and IL-6 levels 48 h postoperatively (r = 0.852, p < 0.05). We conclude that the concentration of complement activation products, IL-6 and the soluble TNF and IL-2 receptors are significantly increased after open heart surgery in children. The cytokine receptor response probably reflects some sort of regulatory mechanism.

Cardiopulmonary Bypass↗
PubMed1995

Activation of the fibrinolytic, coagulation and plasma kallikrein-kinin systems during and after open heart surgery in children.

Activation of the fibrinolytic, coagulation and plasma kallikrein-kinin systems may be responsible for some of the coagulation disorders and inflammatory sequelae seen after extracorporeal circulation. The activation pattern of these systems was studied in 10 children undergoing open heart surgery with extracorporeal circulation. Blood samples were drawn serially before, during and up to 48 h after surgery. The heparin injection induced a significant elevation of plasmin (PL) (p < 0.05) which stayed elevated during extracorporeal circulation. Antiplasmin (AP) values were reduced at wound closure, while the levels were significantly elevated 48 h postoperatively (p < 0.05). alpha 2-antiplasmin-plasmin (APP) increased significantly perioperatively peaking 10 min after the initiation of cardiopulmonary bypass (p < 0.05). The coagulation markers thrombin-antithrombin (TAT) and the prothrombin fragment F1 & 2 increased significantly, peaking at wound closure and at termination of bypass respectively (p < 0.05). Plasma kallikrein (KK) values increased significantly with subsequent decreased levels of prekallikrein (PKK) and kallikrein inhibitor (KKI) after heparin injection. The KK level stayed elevated during cardiopulmonary bypass (CPB). The proenzyme functional inhibition index (PFI index), defined as the sum of deviations from the control values for proenzyme and functional inhibition values of the coagulation, fibrinolytic and plasma kallikrein-kinin systems, correlated significantly to the duration of cardiopulmonary bypass (p < 0.05). We conclude that open heart surgery in children activates the fibrinolytic, coagulation and plasma kallikrein-kinin systems.

Antifibrinolytic Agents↗
PubMed1994

[Endarterectomy of left coronary arteries. An angiographic follow-up study].

From January 1989 to December 1993, 25 patients underwent endarterectomy on the left coronary artery system. Eight of the patients had concurrent endarterectomy of the right coronary artery. The operative mortality consisted of one high-risk patient who died from an intraoperative myocardial infarction. Two patients developed non-fatal perioperative infarction. The follow-up period averaged 27 months (range 4-58 months). At follow-up one patient was lost for evaluation owing to unexpected sudden death, no patients had experienced myocardial infarction, 17 patients (74%) were free of angina, two patients were in NYHA class I and four in NYHA class II. All patients showed an improvement in relation to their preoperative condition. Two asymptomatic patients refused recatheterization, while 21 patients had a control angiographic study. 25 of 34 grafts to endarterectomized vessels were open (patency 74%) compared with 41 of 45 grafts to non-endarterectomized arteries (patency 91%). We find the angiographic and functional results acceptable and they should be acknowledged with reference to patients with diffuse distal coronary artery disease, many of whom would otherwise be considered inoperable.

Adult↗
PubMed1994

[Tetralogy of Fallot. A 20-year material].

Surgical repair of tetralogy of Fallot may be a first stage palliation with secondary physiologic correction or repair as a primary procedure. The aim of palliation is to increase the pulmonary blood flow. Since 1981 we have used an interposition shunt between the subclavian and the pulmonary artery for this purpose. Repair comprises closure of the ventricular septal defect and relief of the pulmonary stenosis. A primary repair may be performed if the pulmonary arteries have reached a certain size. The size and function of the left ventricle must also be able to cope with the increased work load. During the last 20 years, 333 operative procedures have been performed in patients with tetralogy of Fallot. This material comprises 107 shunts and 226 repairs. The total mortality while in hospital was 6%. During the last period from 1990 until January 1993 the mortality in hospital was 3% after operative repair. There have been no mortality following palliative procedures during the same period.

Angiocardiography↗
PubMed1994

Functional characterization of an ex vivo preparation of atrial myocardium from children with congenital heart defects: sensitivity to tyramine and adrenoceptor antagonists.

Small pieces of atrial tissue removed from the cannulation site before cardioplegia were used to develop a method for studying adrenergic regulation of the myocardial contractile force in children operated on for congenital heart defects (CHD). We measured the development of the isometric force of contraction dT/dtmax (T'max). Reduction in basal contractility induced by the beta-adrenoceptor antagonist timolol indicated that the myocardium was about half-maximally stimulated by endogenous norepinephrine (NE), probably released from nerve endings by the electrical stimulation. The inotropic effect of endogenous NE could be further increased by tyramine (EC50 approximately 5 microM). A maximal concentration of tyramine increased T'max by a median of 62.5% above the basal level. Sequential blockade of the beta- and alpha 1-adrenoceptors after tyramine stimulation by timolol and prazosin, respectively, indicated that a near-maximal response to combined adrenoceptor stimulation by endogenous NE was mediated by both beta-adrenoceptors (median 77%) and alpha 1-adrenoceptors (median 23%). The basal level of endogenous NE may conceal inotropic effects by exogenous alpha-agonists added to this type of preparation. This preparation is suitable for studying adrenergic regulation by reversing the effects of endogenous NE.

Adolescent↗
PubMed1993

[Hypoplastic left heart syndrome. Present experiences and future possibilities].

The authors report experiences from Norwood's staged palliation for hypoplastic left heart syndrome performed in Philadelphia on Norwegian children. Although there is no universal agreement that these children should be operated at all, the Norwegian health authorities have decided that all expenses for transport, examination and treatment shall be covered by the National Health Insurance Scheme. Since 1987 a total of 21 children have been transported to USA for operation. Eight of these children have completed all the planned stages of the operative treatment. Two are waiting for stage 3. 11 children have died. The authors discuss how to proceed with regard to treatment of this complicated patient group in future.

Atrial Function, Left↗
PubMed1993

Mental health and psychosocial functioning in adolescents with congenital heart disease. A comparison between adolescents born with severe heart defect and atrial septal defect.

Twenty-six adolescents, aged 13-18 years, with severe congenital heart disease were matched for sex, age and living area with 26 adolescents with repaired atrial septal defect and regarded as physically fit. These two groups were compared according to somatic condition, psychopathology, psychosocial functioning and chronic family difficulties. A higher rate of psychiatric problems in the complex group, an association between psychosocial functioning and physical capacity, as well as an association between psychosocial functioning and chronic family difficulties were observed. These findings suggest that physical capacity is of crucial importance for mental health and functioning of adolescents with congenital heart disease. The association with chronic family difficulties also suggests that a comprehensive biopsychosocial approach is necessary in the treatment and rehabilitation of these patients.

Adolescent↗
PubMed1993

Surgical intervention following failed percutaneous coronary angioplasty.

Percutaneous transluminal coronary angioplasty (PTCA) was performed on 725 occasions at the National Hospital of Norway in 1981-1990. Acute surgical intervention was necessary within 24 hours after PTCA in 15 cases, on indications that included coronary artery dissection (8 cases) and acute thrombotic occlusion (5). Electrocardiographic signs of ischemia were present in 11 patients with anginal pain, while two had severe angina but normal electrocardiogram. Two patients had a non-ischemic indication for surgery. Despite surgery, ten of the 15 patients had acute myocardial infarction. One of the ten died. At follow-up nine of 12 patients were free from angina and three had recurrent symptoms.

Angioplasty, Balloon, Coronary↗
PubMed1993

Prevalence of coxarthrosis in former soccer players. 286 players compared with matched controls.

We compared the occurrence of coxarthrosis in 286 male former soccer players in Malmö with a mean age of 55 years with an age-matched control group. During the last decades about one fifth in both groups had been referred to hip radiography. Coxarthrosis occurred in 5.6 percent of the former soccer players and in 2.8 percent of the control group (P 0.04). Among the 71 élite soccer players the prevalence of coxarthrosis was 14 percent compared with 4.2 percent in age-matched controls and non-élite players. Elite soccer players apparently run an increased risk of developing coxarthrosis.

Adult↗
PubMed1993

Coxarthrosis in farmers.

Recent studies have suggested an excess of coxarthrosis (osteoarthrosis of the hip joint) among Swedish farmers. The prevalence of coxarthrosis in the city of Malmö has previously been studied by coincidental examination of the hip joints on colon roentgenograms. The present study estimates the prevalence of coxarthrosis in farmers by examining the hip joint on roentgenograms of the colon and urinary tract. Fifteen-thousand farmers and farm workers affiliated with the Swedish Farmers' Safety and Preventive Health Association and all farmers aged 40 years or older in the Swedish country of Ostergötland were questioned about previous roentgenographic examinations. Four hundred thirty-five colon examinations and 465 urograms were available and scrutinized by the same physician. Forty-five of 565 male farmers and farm workers, aged 40-64 years, were found to have roentgenographic signs of primary coxarthrosis, compared with ten of 1250 men in the corresponding age group in the urban population of Malmö. The difference represents a rate ratio of 12 with a 95% confidence interval of 6.7 to 21.4. There was no difference in the prevalence of coxarthrosis among the female farmers and women in the urban population. The result suggests a relationship between coxarthrosis and farm work in men.

Adult↗
PubMed1992

Patency of the internal mammary artery used as sequential graft.

In 28 patients with the left internal mammary artery (IMA) used as a sequential coronary artery graft, clinical and angiographic evaluation was made 19-47 months postoperatively. Patency was 96% in the proximal anastomoses and 93% in all the anastomoses. Angiography, however, showed optimal function in only 75% of the distal graft ends. These observations indicate that routine use of left IMA as a sequential graft should be restricted to experienced surgeons. Clinical and angiographic findings did not always correlate, emphasizing that evaluation of IMA-graft patency should include angiography.

Adult↗
PubMed1992

Hemodynamic effects of intraaortic versus intravenous protamine administration after cardiopulmonary bypass in man.

A hemodynamic study of men undergoing elective coronary artery bypass surgery was undertaken to elucidate the side effects of protamine given into the ascending aorta (group A, n = 16) or into the central venous line (group V, n = 16). After termination of extracorporeal circulation, protamine was infused over 120 seconds, and the hemodynamic profile was continuously recorded. During the first minute, the systemic arterial pressure fell to about 60% of the preprotamine level in both groups, but the hemodynamic changes occurred more rapidly (p < 0.05) in group V than in group A, with maximal pressure drop at 61.7 +/- 2.7 vs 74.4 +/- 4.9 seconds. Following spontaneous restoration of the systemic blood pressure, the pulmonary artery pressure rose considerably in both groups, as did the pulmonary capillary wedge and central venous pressures, reaching higher levels in the intravenous group. The cardiovascular responses were again more rapid in group V than in group A (p = 0.004). The degree of systemic hypotension thus did not benefit from use of the intraaortic rather than the intravenous route for administering protamine. The more pronounced and more rapid pulmonary circulatory changes in the intravenous group suggest that the hemodynamic effects of protamine are initiated in the lungs.

Aorta↗
PubMed1992

Single lung transplantation. Surgical experiences with the first seven patients.

Seven single lung transplants are reported. The patients were severely disabled and oxygen dependent below sixty years of age with a poor prognosis. Diagnosis were alfa 1-antitrypsin deficiency (3), sarcoidosis (3) and idiopathic emphysema (1). Multiorgan-harvesting including six hearts, was performed in local or distant hospitals (3). Partial cardiopulmonary bypass simplified transplantation. The surgical procedure was modified with a direct transpericardial approach. Soft tissue wrapping by a vascularized pedicle secured the bronchial anastomosis. The four drug immunosuppressive regimen included cyclosporin A, azathioprine, steroids and antithymocyte globulin. Primary graft function was excellent. Six patients survived the postoperative period and are alive 5-19 months post transplant. Transbronchial biopsies and lung function studies have been helpful in detecting pulmonary rejections. Patient rehabilitation is satisfactory in most patients with improvement in physiologic parameters.

Adult↗
PubMed1992

Morbidity risk factors in human cardiac transplantation. Histoincompatibility and protracted graft ischemia entail high risk of rejection and infection.

Data from the first 103 human heart transplantations performed on 100 recipients (aged 14-62 years) at a single center from November 1983 to January 1990 were analyzed in order to detect morbidity-causing risk factors. Cumulative one- and five-year graft survival was 82% and 68%. Multivariate analysis revealed three independent risk factors for early rejection, viz. HLA-DR and HLA-B mismatches and no prior cardiac surgery. Graft ischemic time exceeding 71 min was an independent risk factor for rejection, especially for moderate or severe events, and for infection. HLA-DR mismatch was an independent risk factor for moderate and severe rejection events and for infections. Finally, patients operated on because of end-stage ischemic heart disease were at significantly higher risk of rejection than those with other cardiac disorders. The study has several implications: Prospective tissue typing for cardiac transplantation and selection of donors may have an impact on graft function: Damage to the graft by prolonged ischemia may be reduced by improved organ preservation.

Adolescent↗
PubMed1991

[Thrombolysis in acute tricuspid valve thrombosis].

The usual treatment of acute heart valve thrombosis is thrombectomy or heart valve replacement. During the last 20 years there have been a few reports of thrombolytic treatment for heart valve thrombosis. We report the successful treatment of two patients with a thrombosed tricuspid heart valve. Both patients received streptokinase. The diagnosis of heart valve thrombosis was based on the clinical status of the patients, cineradiology and echocardiography. Both patients received the combination of salicylic acid and warfarin after streptokinase treatment. Follow-up has shown well functioning heart valves in both patients.

Acute Disease↗
PubMed1991

[Results of 6 1/2 years of heart transplantation at Rikshospitalet].

We discuss our experience from 6 1/2 years of orthotopic heart transplantation at Rikshospitalet (the National Hospital). 112 grafts were performed on 109 patients (19 women and 90 men), mean age 47 years (range 14-63). In the first nine patients the immunosuppressive regimen consisted of cyclosporine A and prednisolone, and in the last 100 azathioprine was added (triple medication). There was no operative mortality. 21 patients died, giving an 81% cumulative survival, with a significantly better prognosis among those who received triple immunosuppressive regimen. The main complications were rejection, infection and arrhythmia. Since our main problem was rejection it is concluded that careful supervision, concentrated on as few cardiologists as possible, and a liberal indication for myocardial biopsy, are decisive for the prognosis.

Adolescent↗