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S Simonsen

Publications and source records attributed to S Simonsen.

At least 73 records · Page 4Linked to original sources
PubMed1996

Influence of the exercise protocol on hemodynamic, gas exchange, and neurohumoral responses to exercise in heart transplant recipients.

BACKGROUND: A gradual accommodation to increasing exercise loads has been recommended for exercise testing in denervated posttransplantation heart recipients. However, how the exercise protocol influence the hemodynamic, gas exchange, and hormonal response to exercise in this not been studied. METHODS: Nine heart transplant recipients tests incremental maximal bicycle ergometry tests in random order. Exercise stages of 1 and 3 minute durations were compared with matched work rate increments ranging between 30 and 40 W. Expiratory gas was measured continuously and arterial blood was sampled at each of the matched work rates. RESULTS: Total exercise duration was 6.4 +/- and 15.3 +/- 0.7 minutes for the 1-minute and 3-minute protocols, respectively. Maximal workload was significantly higher during the 1-minute versus the 3-minute protocol (238 +/- 9 versus 200 +/- 11 W, p < 0.001), but maximal oxygen uptake was not significantly different (25.5 +/- 1.1 versus 26.5 +/- 1.2 ml. min-1.kg-1). Hemodynamic, metabolic, and some hormonal parameters showed marked differences between the two protocols, with significantly higher responses observed during the 3-minute protocol for heart rate, ventilation, lactate, atrial natriuretic factor, and growth hormone. Catecholamine (epinephrine and norepinephrine) and insulin responses did not differ between the two tests. If expressed as a relative exercise intensity (percentage of maximal oxygen uptake) no differences in hormonal responses were observed between the two protocols, except for growth hormone response which remained higher during the 3-minute protocol. CONCLUSIONS: Although maximal oxygen uptake was independent of the exercise protocol in these heart transplant recipients, the exercise protocol has a major influence on the hormonal and metabolic response. The delayed response observed for oxygen uptake and hormonal responses suggests a significant physiologic lag time during the more rapidly incremental protocol. These differences should be taken into account when exercise is used as a method to evaluate the heart transplant recipient.

Adult↗
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

[Reduced physical tolerance in patients with heart failure. Mechanisms and therapeutic effects].

Physical performance is markedly reduced in patients with congestive heart failure, but the reason has not been precisely defined. It has been generally assumed that reduced exercise performance is related to ventricular systolic performance, or as more recently suggested, to impaired left ventricular diastolic function. However, there is no clear relationship between the indices of left ventricular performance and exercise capacity, and there is a dissociation between improvement in haemodynamic parameters and exercise performance. Recent studies suggest that peripheral changes may be major determinants of exercise performance. This may involve reduced blood flow to the exercising limbs because of impaired vasodilatory capacity or intrinsic changes in the skeletal muscle itself. In this review, these factors are considered, and the impact of different therapeutic strategies is discussed.

Exercise↗
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↗
PubMed1995

Cerebral thromboembolic complications associated with the use of a nonionic contrast medium in coronary angiography.

Cerebrovascular complications were registered in 11 patients (0.21%) of 5,339, consecutively submitted to coronary angiography with the nonionic contrast medium iohexol (Omnipaque). Six of the patients had diseases predisposing them to thromboembolic complications, 3 of whom earlier had symptoms of cerebral stroke. Excluding these 6, the incidence of cerebral thromboembolic events was 0.10% in patients with no predisposing diseases. Precise catheterization technique and some anticoagulation and antiplatelet activity therapy are definite precautions against these complications, while the role of the contrast medium is still debated.

Cardiac Catheterization↗
PubMed1993

Acute haemodynamic effects of isradipine in hypertensive heart transplant recipients.

The acute haemodynamic effects of the new calcium antagonist isradipine have been studied in ten hypertensive cardiac transplant recipients. Isradipine 0.01 mg.kg-1 was given IV during right heart catheterization and noninvasively automatic blood pressure measurements. From a baseline blood pressure of 164/114 mmHg the maximum blood pressure reduction was 35 mmHg systolic, 30 mmHg diastolic, and mean 34 mmHg, due to a reduction in systemic vascular resistance, maximum 43%. Cardiac index increased 32%, mainly due to an increase in the stroke volume, as the heart rate rose only by 10%. Left ventricular filling pressure was slightly reduced. We conclude that the main effect of isradipine was a major reduction in left ventricular afterload, comparable to that previously found in other patient groups.

Heart Transplantation↗
PubMed1993

Comparative study of atrial peptides ANF (1-98) and ANF (99-126) as diagnostic markers of atrial distension in patients with cardiac disease.

To evaluate the possible role of atrial natriuretic peptides ANF (1-98) and ANF (99-126) as diagnostic parameters of atrial distension, measurements of peptide levels were performed in 47 patients with chronic ischemic and/or left sided valvular heart disease. Plasma samples were drawn from the pulmonary artery (PA) and superior vena cava (SVC) during diagnostic right heart catheterization. Forty of the patients also underwent left heart haemodynamic measurements, and in 28 patients two dimensional echocardiography with determination of left atrial diameter was performed. Enhanced plasma concentrations of both peptides were observed with increasing severity of heart failure assessed by the NYHA classification. Mean plasma levels of both peptides were closely correlated to mean pulmonary artery pressure (ANF (1-98): n = 47, r = 0.69 (SVC)/r = 0.72 (PA), p < 0.0001; ANF (99-126): n = 46, r = 0.75 (SVC)/r = 0.68 (PA), p < 0.0001) and mean pulmonary capillary wedge pressure (ANF (1-98): n = 47, r = 0.69 (SVC)/r = 0.72 (PA), p < 0.0001; ANF (99-126): n = 46, r = 0.70 (SVC)/r = 0.64 (PA), p < 0.0001). Positive correlations were also obtained between peptide levels and mean right atrial pressure and left ventricular end-diastolic pressure. When patients with high right atrial pressures (n = 2) were excluded from analysis, a significant correlation was found between peptide levels and echocardiography assessed left atrial diameter. The present study demonstrates the close correlation between concentrations of both atrial peptides and cardiopulmonary haemodynamics in patients with chronic heart disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Effect of nifedipine on splanchnic and pulmonary vascular capacitance.

This study examines the hypothesis that nifedipine may increase splanchnic vascular capacitance and thus change the distribution of blood between the splanchnic and pulmonary circulation in heart failure patients. Relative regional blood volumes were determined by equilibrium blood pool scintigraphy during a 10 min baseline period and for 30 min after nifedipine 20 mg sublingually, with simultaneous recordings of systemic and pulmonary arterial pressures, hepatic venous wedge pressure, and cardiac output. Eight patients with ischaemic heart failure received nifedipine. Four patients served as controls. Nifedipine reduced mean arterial pressure and systemic vascular resistance in every patient. There were no significant changes in the relative blood volumes of the intestinal, hepatic, or splenic regions or in hepatic venous wedge pressure (reflecting portal venous pressure), suggesting unchanged splanchnic vascular pressure-volume relationship. Nifedipine caused a 6.3 +/- 1.0% increase in relative pulmonary blood volume and a slight increase in pulmonary vascular distending pressure from 16.1 +/- 2.9 mmHg to 17.5 +/- 2.8 mmHg (P < 0.05), suggesting that the increase in pulmonary blood volume was passively mediated. In conclusion, nifedipine did not change splanchnic vascular capacitance, but caused a small increase in pulmonary blood volume, which probably was a passive response to increased distending pressure.

Adult↗
PubMed1993

Iodixanol in cardioangiography in patients with coronary artery disease. Tolerability, cardiac and renal effects.

Iodixanol is a new nonionic, dimeric contrast medium. With the addition of 18 mmol/l Na+ and 0.3 mmol/l Ca++ to iodixanol 320 mg I/ml a plasma-isotonic solution was obtained. The purpose was to evaluate the suitability of iodixanol for use in cardioangiography by determining the diagnostic efficacy, patient tolerability, and cardiac and renal side-effects. Initially, 14 patients with coronary artery disease were examined using iodixanol. A double-blind, randomized study was then performed in 72 patients, comparing iodixanol and iohexol. Serum and urine were sampled before the examination, and one and 2 days after. The diagnostic information was good and the number of adverse events low with iodixanol. The patients reported significantly less of a sensation of warmth following injection of iodixanol than iohexol. Our results also indicate that iodixanol 320 mg I/ml influences renal function to a lesser degree than does iohexol 350 mg I/ml. We therefore conclude that isotonic iodixanol is a safe contrast medium for use in cardioangiography.

Adult↗
PubMed1992

Hemodynamic evaluation of the CarboMedics prosthetic heart valve in the aortic position: comparison of noninvasive and invasive techniques.

Seventy-three patients with a CarboMedics aortic bileaflet valve prosthesis were examined by Doppler ultrasonography, and 27 of them were also assessed by transseptal catheterization. The ultrasonic mean systolic gradient was 17.1 +/- 5.6 mm Hg for valve size 19 mm, falling gradually with increasing valve size to 6.8 +/- 2.5 mm Hg for size 27 mm. The catheter mean systolic gradient was consistently smaller than the ultrasonic gradient (4.3 +/- 4.8 mm Hg), but Tobit regression analysis showed a significant association between the two methods. In all patients both methods revealed negligible to small amounts of retrograde leakage, which is assumed to be a normal finding for this valve. The effective flow areas of the valves calculated from the ultrasonic data were similar to the in vitro calculated flow areas. The hemodynamic potential of this valve is therefore completely utilized in vivo. The effective orifice area corrected for body surface area increased with increasing valve size, which demonstrates a moderate valve-patient mismatch.

Adult↗
PubMed1992

Hormonal changes in patients with severe chronic congestive heart failure treated by ultrafiltration.

Plasma atrial natriuretic peptide (ANP), antidiuretic hormone (ADH), plasma renin activity (PRA), and circulatory haemodynamics were studied in five patients with chronic congestive heart failure undergoing ultrafiltration on two consecutive days. The patients were in the New York Heart Association class IV, and were considered candidates for heart transplantation. A mean of 3.3 +/- 0.5 litres of fluid was removed during each ultrafiltration. Plasma ANP concentration remained unchanged during ultrafiltration: 369 +/- 151 pg/ml at start and 316 +/- 116 pg/ml at the end, while plasma ADH concentration and PRA increased from 5.1 +/- 2.1 to 7.5 +/- 3.4 pg/ml (P less than 0.02), and 5.9 +/- 3.0 to 7.7 +/- 3.2 ng/ml (P less than 0.03) respectively (n = 10). After treatment, plasma ADH and PRA declined to baseline values within 1 h. Pulmonary artery, pulmonary capillary wedge, and right atrial pressures decreased significantly, while blood pressure and heart rate remained constant during ultrafiltration. A volume of 3.3 +/- 0.5 litres of fluid was removed, and caused an increase in colloid osmotic pressure from 22.0 +/- 3.0 to 33.7 +/- 3.9 mmHg (P less than 0.02). It was unexpected that plasma ANP concentration did not decline. Due to long-standing severe heart failure the atrial wall may have lost some of its elastic properties, resulting in less ability to adapt to reduced filling pressures. Accordingly, atrial wall stretch remained unchanged, explaining the constant ANP levels. Ultrafiltration treatment caused an increased responsiveness to diuretic therapy, and four patients survived long enough to receive heart transplants.

Adult↗
PubMed1992

Differential effect of selective beta 1 and nonselective beta-adrenoceptor blockade on epinephrine and atropine response in normal humans.

Sympathetic stimulation with epinephrine (EPI) combined with parasympathetic blockade with atropine was studied in 10 healthy volunteers premedicated with placebo or three different beta-adrenoceptor blockers: atenolol (62.5 micrograms/kg, beta 1-selective), propranolol (62.5 micrograms/kg, nonselective), and pindolol (7.5 micrograms/kg, nonselective with intrinsic sympathomimetic activity, ISA). EPI infusion (0.06 microgram/kg/min) after placebo increased heart rate (HR) and systolic blood pressure (SBP) and decreased diastolic BP (DBP). Pretreatment with atenolol reduced the HR increase, and caused similar changes in BP. In contrast, pretreatment with propranolol and pindolol decreased HR and increased BP. Combined EPI and atropine (15 micrograms/kg) after placebo increased HR by 40% without causing BP changes. Similar HR changes were observed after administration of all beta-adrenoceptor blockers, but whereas a marked pressor response was observed after propranolol and pindolol a blunted response was observed after atenolol. Propranolol and pindolol reduced myocardial oxygen demand estimated by the HR x BP product after EPI, but this response was abolished by atropine. Serum potassium decreased from 3.9 +/- 0.2 to 3.2 +/- 0.3 mM after EPi and atropine. This effect was less after atenolol, and potassium increased after premedication with propranolol and pindolol. Our results show that nonselective beta-adrenoceptor blockade has a favorable effect on potassium homeostasis and oxygen demand parameters during EPI infusion but causes a marked pressor response, contrary to a beta 1-selective agent, during combined sympathetic stimulation and parasympathetic blockade. They also highlight the importance of the vasodilator cholinergic system as a defense mechanism in such situations.

Adrenergic beta-Antagonists↗
PubMed1992

Nitroprusside and regional vascular capacitance in patients with severe congestive heart failure.

BACKGROUND: This study investigates the effects of sodium nitroprusside on regional vascular capacitance in eight patients with severe congestive heart failure (New York Heart Association class IV) and pulmonary hypertension. METHODS AND RESULTS: Regional relative blood volumes in the splanchnic and pulmonary region were determined by equilibrium blood pool scintigraphy. Hepatic venous wedge pressure and the mean of pulmonary artery and pulmonary capillary wedge pressure were used to represent the distending pressures of the splanchnic and pulmonary capacitance vessels, respectively. The dose of sodium nitroprusside was increased stepwise until systolic pulmonary artery pressure decreased below 50 mm Hg. This caused reductions in mean aortic pressure from 89 +/- 5 to 66 +/- 3 mm Hg (p less than 0.005), in pulmonary capillary wedge pressure from 31 +/- 1 to 16 +/- 2 mm Hg (p less than 0.001), and in hepatic venous wedge pressure from 10.0 +/- 1.0 to 5.9 +/- 0.6 mm Hg (p less than 0.005). Intestinal blood volume increased by 26 +/- 7% (p less than 0.005), whereas hepatic blood volume decreased by 9 +/- 3% (p less than 0.02). Pulmonary blood volume was unchanged. Analysis of intestinal and pulmonary vascular pressure-volume relations showed larger or equal blood volumes contained at lower distending pressures, indicating that sodium nitroprusside reduced smooth muscle tone of the capacitance vessels in these regions. The reduction of hepatic blood volume was compatible with passive expulsion of blood subsequent to reduced venous pressure. There was no change in the count rate from the spleen. CONCLUSIONS: Nitroprusside reduced venous pressure in patients with congestive heart failure by active relaxation of intestinal and pulmonary capacitance vessels. Hepatic vascular volume was probably reduced by a passive mechanism.

Gated Blood-Pool Imaging↗
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↗