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Biomedical subjects

S Rosfors

Publications and source records attributed to S Rosfors.

31 records · Page 2Linked to original sources
PubMed1994

Clinical and hemodynamic effects of stepwise lowering of hemoglobin concentration in patients with intermittent claudication.

This study evaluates the effect of stepwise lowering of the hemoglobin (Hb) concentration on maximal walking distance (MWD) and hemodynamics in patients with intermittent claudication. The results in a study group (n = 6) were compared with those of a control group (n = 6) whose members were not subjected to venesections. An average decrease of Hb concentration from 151 +/- 4 to 121 +/- 3 g/L did not significantly influence MWD, the result being 282 +/- 62 meters before venesections and 255 +/- 54 meters after three to five (mean four) repeated venesections. Transcutaneous oxygen pressure was measured at the dorsum of the foot before and after exercise and did not change with a gradual decrease of the Hb concentration. Maximal heart rate, painfree walking distance, ankle pressure, and blood lactate concentration were also unchanged. An average venesection volume of about 1.4 liters whole blood within fourteen days, without isovolemic replacement, did not change the blood volume, which was 5.1 +/- 0.4 liters before and 5.0 +/- 0.5 liters after venesections. In conclusion, hemodilution accomplished by venesections did not have a clinically or physiologically beneficial effect in patients with severe intermittent claudication. However, hemodynamics and clinical symptoms were not affected by a considerable decrease in the arterial oxygen content within the normal Hb concentration range.

Aged↗
PubMed1993

Duplex ultrasound in patients with suspected aorto-iliac occlusive disease.

Duplex ultrasound scanning was used to localise and classify aorto-iliac occlusive disease. The study included 76 consecutive examinations of 73 patients with signs suggestive of proximal occlusive disease either by history or from traditional non-invasive laboratory investigation. Duplex ultrasound scanning indicated the presence of significant proximal occlusive disease in 70/101 limbs with suspected aorto-iliac disease. In total, 383/393 proximal arterial segments were assessed. A complete evaluation of the aorto-iliac region was possible in 91% of the patients. Duplex scanning was superior to oscillometric amplitude measurements and to CW Doppler examination, especially in patients with concomitant disease of the proximal superficial and deep femoral arteries. Duplex classification of stenoses correlated well with angiographic results obtained in 60 limbs with exact agreement in 194/211 (92%) arterial segments. Three of the patients with disparity between ultrasonography and angiography were investigated with intraarterial pressure measurements demonstrating that these lesions were underestimated by angiography. We conclude that Duplex ultrasound is feasible and accurate in detecting and grading lesions in the aorto-iliac region. This method provides important clinically useful haemodynamic information non-invasively in patients with suspected aorto-iliac occlusive disease.

Adult↗
PubMed1991

Deep venous valvular function assessed with intramuscular pressure recording.

Intramuscular pressures were measured in the anterior tibial muscle with the microcapillary infusion method in 10 patients (11 limbs) with deep venous valvular insufficiency. The results were compared with pressure measurements in healthy controls (n = 8) and in patients with only superficial venous insufficiency (n = 7). The technique could differentiate patients with deep venous reflux from patients with superficial venous reflux and healthy controls. In contrast to the other two groups studied, patients with deep venous reflux were characterized by a small decrease of muscle relaxation pressure during exercise followed by a short recovery time. The method described provides a potential for evaluating regional deep venous valvular function. However, besides deep venous reflux other factors such as rate of arterial inflow, venous capacity and muscle pump function also might influence the results obtained with intramuscular pressure recordings.

Adult↗
PubMed1991

Plethysmographic evaluation of volume changes of the foot and the distal calf in healthy subjects and in patients with distal venous pump dysfunction.

In the present study, plethysmographic methods were used to evaluate the function of the foot pump and the distal calf pump and to characterize the relationship between simultaneously assessed volume changes of the foot and the distal calf in healthy subjects and in patients with distal venous valvular insufficiency. Expelled volume of the foot was found to be more compromised than that of the distal calf in patients where Doppler examination demonstrated deep venous reflux at ankle level. Consequently, EV of the distal calf was less useful in evaluating these patients. Half-refilling time at the two levels was sensitive and equally useful for determining deep valvular function at ankle level.

Adult↗
PubMed1990

Venous photoplethysmography: relationship between transducer position and regional distribution of venous insufficiency.

This study was performed to evaluate the photoplethysmographic technique in venous disease, especially regarding the effect of different positions of the photoplethysmographic transducer and the possibility of measuring regional changes in venous circulation. For this purpose photoplethysmographic recovery times were assessed from three different parts of the lower leg, that is, anterior midcalf level, medial midcalf level, and medial malleolar level. In patients with documented venous disease, regional photoplethysmographic findings were compared with results from venous pressure measurements, ascending/descending phlebography, foot volumetry, venous plethysmography, and Doppler investigation of the anterior tibial veins. The best correlation with pressure and volume recordings at the foot was obtained at the medial malleolar level. Only photoplethysmographic recovery times recorded at the anterior aspect of the leg were influenced by reflux in the anterior tibial veins. The present results indicate that photoplethysmographic recovery times reflect regional venous hemodynamics rather than overall venous hemodynamics in the limb. Photoplethysmographic recovery times were also found to be more related to superficial than to deep venous insufficiency. The results might have clinical implications when evaluating patients with regional venous dysfunction and in follow-up studies after venous surgery.

Adult↗
PubMed1990

Assessment of deep venous incompetence: a prospective study comparing duplex scanning with descending phlebography.

In this prospective study duplex scanning was performed in 21 consecutive patients (23 lower extremities) referred for descending phlebography. The grade of deep venous insufficiency (Grades 1-4) was estimated in a blinded fashion with phlebography and duplex technique. Agreement occurred in 15 of 23 lower extremities. Discrepancies were found particularly in patients with minor degrees of reflux. The patients with reflux below the knee according to phlebography were also identified with ultrasonography. The authors found duplex scanning to be accurate method of evaluating deep venous valvular function. With duplex--but not with phlebography--it was also possible to diagnose isolated lower extremity valvular insufficiency.

Female↗
PubMed1990

Important predictors of the outcome of physical training in patients with intermittent claudication.

Hemodynamic and endocrine variables have been unsuccessful to predict improvement in walking distance in patients with intermittent claudication following structured training programs. In the present study we evaluated the predictive value of a number of hemodynamic and endocrine parameters. In addition we included information on cognitive factors such as stress and the belief in the structured training and motivation to participate. Twenty-five elderly subjects were studied. Significant improvement in overall walking distance was achieved. The most important explanatory variables of relative improvement in walking distance were belief in training, initial walking distance and number of smoke years. The results support the belief that cognitive factors are of major importance in predicting functional effects of structured training programs for patients with intermittent claudication.

Aged↗
PubMed1990

Severity and location of venous valvular insufficiency: the importance of distal valve function.

Venous calf pump function was evaluated with special reference to distribution and severity of deep venous reflux at different levels. A combination of ultrasonography, foot volumetry and venous plethysmography was used in 100 consecutive patients, 32 of whom were also studied with phlebography and intravenous pressure measurements. A clear relationship was found between clinical stage of chronic venous insufficiency and number of segments with reflux. Clinically important deep venous insufficiency was found particularly in patients with reflux in the distal posterior tibial veins, even in the presence of competent popliteal valves. The results demonstrated the calf pump to be functionally divided into a series of pumps, with the distal part more important than the proximal. The importance of evaluating venous valvular function at different levels for adequate assessment of venous calf pump function is emphasized.

Adult↗
PubMed1989

Longterm neuroendocrine and metabolic effects of physical training in intermittent claudication.

Twenty-five elderly patients with peripheral vascular disease and intermittent claudication were prospectively followed during a six-month session of physical training. Neuroendocrine and metabolic patterns as well as effects on walking performance were assessed during the training period. At the initial evaluation there was an inverse association between walking distance and serum cortisol and blood glucose levels. The walking distance increased during the training period. A positive effect on glucose homeostatis was seen with decreased basal fructosamine levels after training. During physical exercise a decrease in insulin and an increase in growth hormone was seen. Changes in growth hormone were, in contrast to insulin, more related to the pain level perceived than to the work load imposed. Apart from the marked effects on physical performance the results of the study suggest an improvement of hormonal and metabolic balance after physical training. This regularly applied exercise program improved the health status of rather old people.

Aged↗
PubMed1988

Venous circulation after fasciotomy of the lower leg in man.

The study was performed in order to evaluate the effect of fasciotomy of the lower leg on venous circulation and venous muscle pump function. Twenty patients with unilateral fasciotomy were investigated with photoplethysmography (PPG), strain-gauge plethysmography, foot volumetry and Doppler ultrasound. In the operated legs shorter venous refilling times were registered both with PPG (P less than 0.01) and foot volumetry (P less than 0.05). PPG recordings from different parts of the leg showed regional changes in venous circulation with shorter refilling times only with the transducer placed over the affected muscular compartment. With foot volumetry a reduced expelled volume was found in patients earlier treated with extensive fasciotomies. The results of the study indicate that an intact muscle fascia is of importance for venous return and venous pump function.

Adolescent↗
PubMedDate not supplied

Effect of reversible hypoperfusion on left ventricular volumes measured with gated SPECT at rest and after adenosine infusion.

BACKGROUND: The aims of this study were to assess the degree of postischemic left ventricular (LV) dilatation after adenosine stress and to determine the extent to which LV volumes measured with gated single photon emission computed tomography (SPECT) correspond to those obtained by echocardiography. METHODS: Eight-frame gated SPECT with a 2-day technetium-99m tetrofosmin acquisition protocol was used. End-diastolic (EDV) and end-systolic (ESV) volumes were measured automatically with the quantitative gated SPECT algorithm. Reversible myocardial hypoperfusion was evaluated with a 16-segment, 4-point perfusion score model. LV volumes at rest were also measured with echocardiography by use of the biplane Simpson rule. RESULTS: Twenty-two patients (group 1) showed normal perfusion and normal LV systolic function, whereas 33 patients (group 2) had evident coronary heart disease with reversible hypoperfusion. Patients in group 2 had greater EDV and ESV than those in group 1 both at rest and poststress. A greater reduction in ESV from poststress to rest was seen in group 2, which resulted in a slight increase in ejection fraction for patients in this group. The change in ESV from poststress to rest was significantly influenced by the degree of reversible hypoperfusion and by the change in heart rate from poststress to rest. We found a good correlation between LV volumes measured with gated SPECT and echocardiography. CONCLUSION: LV volume measurements with quantitative gated SPECT are comparable to those obtained with echocardiography. Patients with ischemic heart disease have greater LV volumes than patients with normal perfusion. Exercise-augmented adenosine infusion in patients with ischemic heart disease affects ESV more than EDV. This response is partly modulated by the degree of reversible hypoperfusion and possibly represents a minor degree of poststress stunning.

Adenosine↗