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S Slørdahl

Publications and source records attributed to S Slørdahl.

18 recordsLinked to original sources
PubMed2003

Left ventricular mechanics during exercise: a Doppler and tissue Doppler study.

AIMS: To study left ventricular mechanics of exercise with Doppler and tissue Doppler. METHODS AND RESULTS: Twenty-one males (mean age, 26; height, 184 cm; weight, 84 kg), exercised on a bicycle, with increasing workload, with oxygen uptake, Doppler flow and tissue Doppler recordings during exercise. There was correlation between peak systolic LVOT flow and annulus velocity; R=0.72, (p<0.001) and between peak mitral E flow and annulus E(a) velocity; R=0.68(p<0.001). Finally there was correlation between peak LVOT and mitral flow velocity; R=0.83(p<0.001) and peak systolic and early diastolic annulus velocity R=0.69(p<0.001). All intervals of the heart cycle decreased with RR-interval. There was a linear relation between diastolic filling and RR-interval, while ejection period was less increased with RR-intervals above 600 ms, and thus not a linear relationship. There was no change in E/E(a) ratio during exercise. CONCLUSIONS: Mechanism for increased filling as well as ejection during exercise seems to be increased contraction and relaxation velocity, with no evidence of Frank-Starling mechanism. Bazett's formula gives a better heart rate correction of LVET at high heart rates than Weissler's.

Adult↗
PubMed2001

Strain rate imaging in normal and reduced diastolic function: comparison with pulsed Doppler tissue imaging of the mitral annulus.

OBJECTIVES: The pixel velocity values obtained by color Doppler tissue imaging (DTI) can be processed to velocity gradients as a measure of longitudinal strain rate with a technique termed strain rate imaging (SRI). Color mapping of strain rate does show the spatial-temporal relations of the diastolic phases. The phases of early filling and late filling during atrial systole can be seen to consist of a stretch wave in the myocardium, propagating from the base to the apex. Diastolic function is characterized by both peak strain rate and propagation velocity of this wave. The goals of this study were to establish normal values for these measurements and to study the changes with minimal diastolic dysfunction. METHODS: Twenty-eight healthy control subjects and 26 patients with hypertension and normal systolic function were studied. The patients had normal blood pressure on treatment, normal ejection fraction, minimal hypertrophy, and moderately prolonged deceleration and isovolumic relaxation times. Real-time SRI color cineloops, ordinary echocardiography and Doppler recordings, and pulsed wave DTI from the mitral ring were acquired and processed. RESULTS: Patients showed a reduction of systolic and early diastolic tissue velocities and strain rates and no significant increase in late diastolic tissue velocity and strain rate. Propagation velocity of diastolic strain during both early and late filling phases was reduced in the patients. The combination of changes in peak strain rate and propagation velocity of strain rate corresponded with changes in DTI. CONCLUSION: Diastolic deformation of the ventricle can be shown as a complex series of events, with temporal sequences in the ventricle. The peak strain rate and the propagation velocities of strain rate can describe the two main diastolic events: early and late filling. In reduced diastolic function, both are reduced during early filling. The velocities of the mitral ring are the result of this combination. This adds information about the physiology and pathophysiology of diastole.

Adult↗
PubMed2000

Semiautomatic contour detection in ultrasound M-mode images.

We have developed a method for semiautomatic contour detection in M-mode images. The method combines tissue Doppler and grey-scale data. It was used to detect: 1. the left endocardium of the septum, the endocardium and epicardium of the posterior wall in 16 left ventricular short-axis M-modes, and 2. the mitral ring in 38 anatomical M-modes extracted pair-wise in 19 apical four-chamber cine-loops (healthy subjects). We validated the results by comparing the computer-generated contours with contours manually outlined by four echocardiographers. For all boundaries, the average distance between the computer-generated contours and the manual outlines was smaller than the average distance between the manual outlines. We also calculated left ventricular wall thickness and diameter at end-diastole and end-systole and lateral and septal mitral ring excursions, and found, on average, clinically negligible differences between the computer-generated indices and the same indices based on manual outlines (0.8-1.8 mm). The results were also within published normal values. In conclusion, this initial study showed that it was feasible in a robust and efficient manner to detect continuous wall boundaries in M-mode images so that tracings of left ventricular wall thickness, diameter and long axis could be derived.

Blood Flow Velocity↗
PubMed1996

Hemodynamics in white coat hypertension compared to ambulatory hypertension and normotension.

Hemodynamic alterations associated with the blood pressure response in subjects with white coat hypertension may provide insight into the pathophysiologic mechanisms of this condition. Systemic arterial hemodynamics were investigated with a recently validated method based on noninvasive estimates of aortic root pressure and flow in 28 subjects with white coat hypertension (diastolic pressure > or = 90 mm Hg measured by the general practitioner [GP arterial pressure] and ambulatory daytime pressures < 140/90 mm Hg), in 23 subjects with previously untreated, ambulatory hypertension (GP diastolic pressure > or = 90 and < 115 mm Hg and ambulatory daytime diastolic pressure > or = 90 mm Hg), and in 32 normotensive subjects. The groups did not differ significantly concerning age, gender, body surface area, heart rate, stroke index and cardiac index, but total peripheral resistance index was increased and total arterial compliance reduced in the white coat group and the hypertensive group compared to the normotensive group. The subjects in the white coat group with a systolic arterial pressure during echocardiography that was > 5 mm Hg higher than the ambulatory daytime systolic pressure (n = 19) had increased cardiac index, increased total peripheral resistance, and decreased total arterial compliance compared to the normotensive group. The subjects in this group with a hemodynamic pattern characterized by a high ratio of cardiac index/peripheral vascular resistance were significantly younger than the subjects with the opposite pattern. Thus, the blood pressure increase in subjects with white coat hypertension is associated with increased cardiac output, increased peripheral vascular resistance, and reduced total arterial compliance, but the hemodynamic pattern may be influenced by age.

Adult↗
PubMed1991

[Acute admissions of asthmatic patients. Registration of acute admissions of patients with asthma at the pediatric clinic, Regionsykehuset, Trondheim 1988].

In 1988 there were 179 emergency admissions to the Department of Paediatrics, Regional Hospital, Trondheim, because of asthma. These comprised 22% of the total number of 812 admissions to the emergency unit this year. 178 of the 179 patients' records were found and used in this registration. 46% of the admissions referred to children who had previously been admitted for asthma. Half of the 179 admissions referred to children under 2.5 years of age, and 69% were boys. The main precipitating cause of the admissions was preceding respiratory infection. In 71% of the admissions the child had a family history of atopy. 125 patient records with information about the home environment showed that in 50% of these cases, the children were exposed to cigarette smoking and 34% had domestic animals at home. In 67% of the admissions the patients were taking antiasthmatic medication prior to hospitalization. The most frequently used drugs were Beta-2-agonists in mixture formulas. Less than 7% of the drugs used were corticosteroids. Management of childhood asthma may be improved and emergency admissions prevented by motivating parents to avoid potent allergens and exposure to tobacco smoke at home, supplemented by better education of patient and parents in antiasthmatic medication.

Adolescent↗
PubMed1991

T-cell receptor tau delta +/CD3+4-8-T- cell acute lymphoblastic leukemias: a distinct subgroup of leukemias in children. A report of five cases.

In a 10-year study of T-cell acute lymphoblastic leukemias (T-ALL) in children, we have identified five cases expressing the T-cell receptor tau delta (TCR tau delta). The incidence (26%) of TCR tau delta+T-cell leukemias in our material was high. Clinically, the TCR tau delta+ leukemias represented a distinct subgroup of T-cell leukemias. Mean age at onset of disease, 1.8 years, was remarkably low for mature T-cell leukemias. White blood cell counts were high, lymph node enlargements were discrete, and no mediastinal tumors were seen. Four of five TCR tau delta+ leukemias carried rearrangements of the C tau 2 gene, and transcribed the T-early alpha genetic element.

Antigens, CD↗
PubMed1984

Binding of transferrin and uptake of iron by K-562 cells.

Transferrin-mediated uptake of iron has been studied in K-562 human erythroleukaemia cells. K-562 cells accumulate iron from transferrin by a temperature-dependent mechanism linearly with time for at least 150 min. At 37 degrees C the uptake reaches a saturation level of approximately 25 pmol iron/10(6) cells/h at a concentration of iron (as iron-transferrin) of 5 mumol/l. The binding of transferrin reveals saturation kinetics, at 0.2 mumol/l of transferrin specific binding amounts to 1.8 pmol/10(6) cells. Relative to the binding of transferrin the uptake of iron increases with time. The ability of K-562 cells to accumulate iron declines with days in culture by approximately 50% from day 1 to day 5. The results are compatible with iron uptake by receptor-mediated endocytosis of transferrin, dissociation of iron within the cell and exocytosis of apotransferrin.

Cell Line↗
PubMed1982

Septicaemia due to Yersinia enterocolitica after oral overdoses of iron.

Septicaemia occurred after accidental oral overdoses of iron in two previously healthy children. Yersinia enterocolitica serotype 0:3 was recovered from blood and stool cultures in both patients. Enhanced growth of Y enterocolitica in the intestine combined with damage of intestinal mucosa may have been of major importance for the development of generalised infection in these cases. Iron and the iron chelating agent desferrioxamine may possibly have a pathogenetic role in such circumstances.

Female↗