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| 2. |
- Hayashi, Shirley Yumi, et al.
(författare)
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Acute effects of low and high intravenous doses of furosemide on myocardial function in anuric haemodialysis patients : a tissue Doppler study
- 2008
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Ingår i: Nephrology, Dialysis and Transplantation. - : Oxford University Press (OUP). - 0931-0509 .- 1460-2385. ; 23:4, s. 1355-1361
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Tidskriftsartikel (refereegranskat)abstract
- Background. In patients with pulmonary oedema and preserved renal function, furosemide has not only a renal, but also a vascular effect, causing a rapid fall in left ventricular filling pressure accompanied by an increase in venous compliance. Previous studies have shown conflicting findings regarding the vascular effects of furosemide in patients with end-stage renal disease (ESRD). The objective of our study was to investigate whether furosemide induces changes in central cardiac haemodynamics in anuric ESRD patients, using conventional echocardiography and colour tissue Doppler velocity imaging (TVI), a new quantitative and sensitive method. Methods. Repeated low doses (40 mg followed by an additional dose of 40 mg after 30 min) of i.v. furosemide were administered to 12 (61.6 +/- 16 years, 7 men) and a high dose (250 mg) of i.v. furosemide to 6 (64.1 +/- 3.6 years, 5 men) clinically stable anuric haemodialysis (HD) patients. Conventional two-dimensional echocardiography and colour TVI images were recorded immediately before (0 min) the furosemide infusion in both groups, and in the group receiving the repeated low-dose infusion (at 0 and 30 min), 10, 20, 30, 40, 50 and 70 min after the administration of the first infusion. In the group receiving the single high dose of furosemide the ultrasound investigation was repeated 10, 20, 30 and 40 min after the infusion. The myocardial tissue velocities (v; cm/s) for isovolumetric contraction (IVC), peak systole (PS), early (E') and late (A') myocardial diastolic filling velocities were measured in the left ventricle (LV) at six sites (infero-septal, antero-lateral, inferior, anterior, infero-lateral and antero-septal walls) at the basal region. IVC time (IVCT), IV relaxation time (IVRT), PS time (PSt), RR interval, mitral annulus motion (MAM), strain rate (SR), left ventricular filling pressure (E/E') and cardiac output were also measured. The average of the different walls was used to evaluate global function. Right ventricle (RV) dynamics was evaluated from measurements of IVC velocity (IVCv), peak systolic velocity (PSv), E' and A' from the RV free wall. Results. No significant changes in cardiac output, IVCv, PSv, SR, MAM, E', A', E'/A', IVRT and LV filling pressure were observed, indicating that neither 40 mg (plus additional 40 mg after 30 min) nor 250 mg of furosemide had any measurable effects on LV filling pressure and LV and RV systolic and diastolic function. Conclusions. In anuric HD patients, low and high doses of furosemide had no significant effects on central cardiac haemodynamics. Therefore, the use of furosemide infusion in anuric ESRD patients with acute pulmonary oedema is not supported by the results of this study.
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- Hayashi, Shirley Yumi, et al.
(författare)
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Improvement of cardiac function after haemodialysis : Quantitative evaluation by colour tissue velocity imaging
- 2004
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Ingår i: Nephrology, Dialysis and Transplantation. - : Oxford University Press (OUP). - 0931-0509 .- 1460-2385. ; 19:6, s. 1497-1506
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Tidskriftsartikel (refereegranskat)abstract
- Background. Overhydration and accumulation of uraemic toxins may influence the myocardial function in haemodialysis (HD) patients. To evaluate cardiac function and the effects of fluid and solute removal during a single session of HD, colour tissue velocity imaging (TVI) was used. This new technique, which is less load dependent than conventional echocardiography, allows an objective quantitative assessment of myocardial contractility, contraction and relaxation. Methods. Conventional echocardiographic and TVI images were recorded before and after a single HD session in 13 clinically stable HD patients (62 +/- 10 years, six males) and in 13 sex- and age-matched healthy controls. Myocardial tissue velocities (v; cm/s) for isovolumetric contraction (IVC), peak systole (PS), early (E) and late (A') diastolic filling and strain rate (SR) were measured. Results. Left ventricular hypertrophy (LVH) was present in 12 patients. TVI gave additional information in comparison with conventional echocardiography. Before HD, PS (5.0 +/- 0.8 vs 6.0 +/- 1.2 cm/s, P < 0.05), E' (5.7 +/- 1.7 vs 7.3 +/- 2.0 cm/s, P < 0.05) and A' (6.6 +/- 1.7 vs. 8.3 +/- 2.9 cm/s, P < 0.05) velocities were lower in the patients than in the controls, indicating systolic and diastolic dysfunction. The HD session increased IVCv (4.0 +/- 1.7 to 5.5 +/- 1.9 cm/s; P < 0.001), PSv (5.0 +/- 0.8 to 5.7 +/- 0.8 cm/s; P < 0.05) and SR (0.7 +/- 0.2 to 0.9 +/- 0.2 1/s; P < 0.05) and decreased E/E' (16.7 +/- 7.7 to 12.2 +/- 4.0, P < 0.05), indicating improved systolic function and decreased LV filling pressure, respectively. Linear regression analysis demonstrated a dependency of systolic contraction (PSv) and contractility (IVCv) upon plasma levels of phosphate (r(2) = 0.70, P < 0.005, r(2) = 0.33, P < 0.01). Conclusions. Using TVI, HD patients demonstrate myocardial dysfunction, which is found less frequently when using conventional echocardiography. The systolic function seems to be impaired by high plasma levels of phosphate and an increased Ca x P product. One single session of HD improved systolic function as indicated by increases in IVCv, PSv and SR. Further studies are needed to clarify if this effect of HD is due to the acute removal of fluid, the removal of solutes or both.
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| 4. |
- Hayashi, Shirley Yumi, et al.
(författare)
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Left ventricular function in patients with chronic kidney disease evaluated by colour tissue Doppler velocity imaging
- 2006
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Ingår i: Nephrology, Dialysis and Transplantation. - : Oxford University Press (OUP). - 0931-0509 .- 1460-2385. ; 21:1, s. 125-132
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Tidskriftsartikel (refereegranskat)abstract
- Background. Cardiovascular disease is the leading cause of death in chronic kidney disease (CKD) patients. Tissue Doppler velocity imaging (TVI) is a new objective method that accurately quantifies myocardial tissue velocities, deformation, time intervals and left ventricular (LV) filling pressure. In this study, TVI was compared with conventional echocardiography for the assessment of left ventricular (LV) function in pre-dialysis patients with different stages of CKD. The results obtained by TVI were used to analyse possible relationships between LV function and clinical factors such as hyperparathyroidism and hypertension that could influence LV function. Methods. Conventional echocardiography and TVI images were recorded in 40 patients (36 men and 4 women, mean age 60 +/- 14 years, range 28-80 years) and in 27 healthy controls (21 men and 6 women, mean age 58 +/- 17 years, range 28-82 years). Twenty-two patients had mild/moderate CKD (CCr > 29 ml/min; Group 1) and 18 patients had severe CKD (CCr <= 29 ml/min; Group 2). Using TVI, the myocardial tissue velocities (v; cm/s) for isovolumetric contraction (IVCv), peak systole (PSv), early (E') and late (A') diastolic filling velocities as well as strain rate (SR), mitral annulus displacement, isovolumetric relaxation time (IVRT) and LV filling pressure were estimated using TVI. The average of six LV wall measurements was used to evaluate LV global function. Results. Using TVI, we were able to identify significantly more patients with diastolic dysfunction than using conventional echocardiography (33 vs 26, P < 0.05). There was no difference in the prevalence of diastolic dysfunction between Group 1 and 2. However, using TVI, Group 2 CKD patients had lower E' velocities (6.2 +/- 1.9 vs 8.0 +/- 2.9 cm/s, P < 0.05) and higher IVRT (137.4 +/- 13 vs 88.2 +/- 26 ms, P < 0.001) in comparison with controls, indicating more accentuated diastolic dysfunction. Systolic blood pressure (SBP) was associated with E' velocities (rho = -0.68, P < 0.005) and E'/A' was strongly associated with SBP (rho = -0.60; P < 0.01) and PTH (rho = -0.64, P < 0.005) in Group 2. Using conventional echocardiography, there was no difference in the prevalence of systolic and diastolic dysfunction between patients with and without LVH. However, using TVI, patients with LVH had significantly lower IVCv (2.8 +/- 1.3 vs 3.8 +/- 1.5 and 3.8 +/- 1.5 cm/s, P < 0.05) and PSv (5.5 +/- 1.0 vs 6.3 +/- 1.2 and 6.4 +/- 1.3 cm/s, P < 0.05) compared with patients without LVH and controls, and they also had lower E' velocities (7.1 +/- 2.7 vs 8.0 +/- 2.9 cm/s, P < 0.05) compared with controls, indicating disturbances in systolic and diastolic left ventricular function. Conclusions. TVI provided additional information on left ventricular function in CKD patients. In patients with advanced renal failure, TVI revealed more accentuated diastolic dysfunction associated with increased systolic blood pressure (SBP) and increased levels of PTH. TVI also demonstrated disturbances in contractility and contraction in patients with LVH, which could not be detected by conventional echocardiography.
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| 5. |
- Magnusson, Martin, 1978-
(författare)
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Experimental studies of small intestinal permeability and function in uremia
- 1991
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The intestinal permeability has been investigated in experimental chronic and acute uremia in rats. The permeability and the mucosal ability to exclude larger molecules have been measured using differently sized polyethylene glycols (PEG 400 and 1000: mean weights of 400 and 1000 dalton, range 326-1162 dalton). The permeation (uptake) of the differently sized molecules has been estimated from the urinary recovery of the PEGs after oral administration of the permeability markers. The effects of two different diets (high-and low-protein) have been studied inexperimental chronic uremia and in normal rats. The renal excretion of the PEGs after intravenous administration has also been investigated in chronic uremic rats. Furthermore, the effect of experimental acute uremia on intestinal brush border peptidases, disaccharidases and mucosal morphology have been studied. Finally has the urinary recovery of PEGs been investigated in patients with renal insufficiency compared to healthy subjects.The urinary recovery of PEGs was reduced after intravenous administration in chronic uremic rats. The relative excretion of the smaller PEGs was, however, increased compared to the larger ones in the uremic rats. The opposite was found in the control rats. Intestinal permeability, measured as an increased urinary recovery after oral administration of larger PEGs, was increased in chrortic uremic rats.The overall urinary recovery of the PEG molecules was reduced in patients with renal insufficiency. However, the relative excretion of the differently sized PEGs indicated a relative increased uptake of larger molecules also in uremic patients suggesting a more permeable gut.An opposite pattern was seen in experimental acute uremic rats, reduced urinary recovery along with a relative decreased excretion of larger molecules compatible with a less permeable gut.Moreover, both in the chronic uremic and in the control rats treated with low-protein diet was a reduction of intestinal permeability seen.Increased activity of brush border peptidases was found in acute uremic rats. Minor morphological changes, shortening of the microvilli of the enterocytes in the small intestine were also observed. On the other hand, no alterations of the disaccharidases were measured.In conclusion, the change in intestinal permeability indicates a more leaky mucosal barrier in chronic uremia. Functional alterations i.e. increased peptidase activity was seen in acute uremic rats. A more leaky gut might allow potentially toxic, infectious and immunogenic substances to pass more freely over the mucosa in chronic uremia.
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| 6. |
- Stenvinkel, Peter, et al.
(författare)
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Statin treatment and diabetes affect myeloperoxidase activity in maintenance hemodialysis patients
- 2006
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Ingår i: Journal of the American Society of Nephrology. - 1046-6673 .- 1533-3450 .- 1555-905X. ; 1:2, s. 281-287
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Tidskriftsartikel (refereegranskat)abstract
- Myeloperoxidase (MPO), which is secreted during activation of neutrophils, may serve as one mechanistic link among persistent inflammation, oxidative stress, and cardiovascular disease. This study related MPO activity to inflammatory and oxidative stress biomarkers, comorbidity, and ongoing medication in prevalent hemodialysis (HD) patients. In a cross-sectional evaluation of 115 prevalent (vintage 25 mo) HD patients (62 men; 63 +/- 1 yr), data on comorbidity (Davies score), diabetes, medication (statins and antiltypertensive drugs), nutritional status (subjective global assessment), blood lipids (cholesterol, HDL cholesterol, and triglycerides), inflammatory biomarkers (serum albumin, C-reactive protein, TNF-alpha, and IL-6), oxidative stress biomarkers (pentosidine, 8-hydroxydeoxyguanosine, and MPO activity) were recorded. Patients with MPO activity greater than the median had significantly (P < 0.05) lower serum albumin levels (33.2 +/- 0.7 versus 35.0 +/- 0.5 g/L), higher 8-hydroxydeoxyguanosine levels (1.26 +/- 0.08 versus 1.05 +/- 0.06 ng/mb, and a lower prevalence of statin treatment (18 versus 36%). Therefore, the median MPO activity was significantly (P < 0.05) lower (17.7 versus 26.6 Delta OD630/min per mg protein) in the subgroup of 31 HD patients with ongoing statin treatment. In a multiple regression model, correction for the impact of age, gender, vintage, serum cholesterol, serum albumin, comorbidity, diabetes, and statin use, only diabetes (P < 0.01) and statin use (P < 0.01) were significantly associated to MPO activity. Fourteen patients who had diabetes and were receiving statin treatment had markedly (P = 0.001) lower median (19.9 versus 41.2 Delta OD630/min per mg protein) MPO activity compared with 18 who had diabetes and were not taking statins. This cross-sectional study suggests that both diabetes and statin treatment affect MPO activity in prevalent HD patients.
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