Clinical characteristics associated to atrial fibrillation in chronic hemodialysis patients.

BACKGROUND: Atrial fibrillation (AF) is the most common sustained arrhythmia diagnosed in non-uremic patients and its prevalence increases in older subjects, however, information concerning AF in dialysis patients is scarce. Therefore, we carried out a prospective cross-sectional study from September 1996 to December 1996 in order to evaluate the prevalence and some of the clinical characteristics associated to AF in hemodialysis (HD) patients. SUBJECTS AND METHODS: 316 HD patients (age 63 +/- 12 years, dialysis duration 69 +/- 71 months) treated in three different hospital-based units were studied. Standard 12-lead electrocardiograms (ECGs) carried out in the interdialytic day during the study period were reviewed. Data concerning age, history of ischemic heart disease (IHD), cerebrovascular disease (CVD), peripheral vascular disease (PVD), presence of diabetes, smoking history and antihypertensive therapy were collected. Systolic and diastolic blood pressure, fasting cholesterol and triglycerides, albumin and hemoglobin were also derived from the clinical records. Performance status was assessed by Karnofsky index (Ki). RESULTS: 74 patients (23.4%) had persistent AF, i.e. presence of AF in all (at least two) ECGs performed in the study time. Patients with AF were older (age 69 +/- 10 vs 62 +/- 12 years, p < 0.001), had lower Ki (54 +/- 20 vs 68 +/- 17, p < 0.01), cholesterol (182 +/- 46 vs 198 +/- 52 mg/dl, p < 0.01) and albumin (3.9 +/- 0.5 vs 4.1 +/- 0.5 g/dl, p < 0.001) compared to those with no AF. Prevalence of IHD (44.5% vs 19%, p < 0.05) and PVD (23% vs 11%, p < 0.05) was higher among AF patients. Logistic regression analysis showed that IHD (p < 0.001) and Ki (p < 0.01) were independently associated to AF. CONCLUSION: We conclude that AF is a frequent arrhythmia in HD patients treated in hospital-based dialysis units, especially in those with low performance status. It appears to be associated to the atherosclerotic damage of coronary arterial tree. Prospective studies are necessary to assess whether it could contribute to cardiovascular morbidity and mortality in end-stage renal disease.

[Erythrocyte carbonic anhydrase in subjects on periodic hemodialysis]. / Anidrasi carbonica eritrocitaria in soggetti sottoposti ad emodialisi periodica.

Red cell carbonic anhydrase isoenzymes I and II have been measured by means of cellulose acetate membrane electrophoresis in patients with chronic renal failure and dependent on periodic hemodialysis; these patients showed a chronic anemia due to many factors. Carbonic anhydrase isoenzymes were higher in uremic and anemic patients than in the controls. Since hemoglobin can act as a protons acceptor from the active site of carbonic anhydrase during the hydratation of CO2 (and vice-versa), the increase of carbonic anhydrase can facilitate, via the Bohr effect, the transfer of the oxygen to the peripheral tissues. Therefore an increase of red cell carbonic anhydrase can constitute a compensating mechanism of anemic hypoxia in uremic patients.

Henoch-Schönlein purpura after Salmonella hirschfeldii infection.

The authors present a case of Henoch-Schönlein purpura in a young soldier (19 years old) which they consider important for its etiology and the length of its oligoanuric phase. The syndrome followed a Salmonella hirschfeldii infection, and a protracted oligoanuric phase was followed by nephrotic syndrome and selective glomerular proteinuria which lasted for 1 year. The young man recovered after the eradication of the Salmonella. It seems possible that there was an overall anomalous regulation of the 'lymphoid system of the mucosa', perhaps dependent on a genetic predisposition.

Ornithine decarboxylase activity and polyamines level from red cells lysate of uraemic patients and normal healthy subjects.

We studied the ornithine decarboxylase (ODC) activity and polyamines (PAs) content in the red cells lysate before and after haemodialysis of 15 uremic patients and 15 healthy subjects. ODC activity is significantly increased after haemodialysis but the PAs concentrations (particularly spermine and spermidine) do not increase. This could be because of a minimal loss of PAs surplus production. On the contrary the increase of ODC activity could be explained in several ways, e.g. by stimuli during haemodialysis (hypoxia of the first hour of treatment, decrease of plasmatic osmolarity and biological stimulation of the blood during its passage through the filter).

Response of plasma aldosterone to sequential ultrafiltration, dialysis and conventional hemodialysis.

The response of plasma aldosterone to sequential ultrafiltration dialysis has been studied during 16 sessions and compared with the response to 12 conventional sessions of hemodialysis. During the isolated ultrafiltration phase an important and significant increase in plasma aldosterone and plasma renin activity was observed. There was a substantial removal of extracellular fluid, but no change in plasma biochemistry. During conventional hemodialysis over the same time scale the concentration of plasma aldosterone decreased significantly, plasma renin underwent a small increase and plasma osmolality and plasma potassium decreased. Several possible pathophysiological mechanisms are discussed. We conclude that rapid isosmotic ultrafiltration without change in plasma potassium or sodium, the maintenance of plasma potassium at normal elevated values, and the increase of angiotensin II are factors favoring aldosterone biosynthesis.

Positive aluminium balance in patients on regular peritoneal treatment: an effect of low dialysate pH?

Aluminium concentration was determined in dialysates used for HD and for PD and in the serum of normal subjects and of uraemic patients on treatment with HD and with PD. The main finding of this study was that serum A1 levels are significantly higher in patients on PD than in patients on HD. We conclude that the use of dialysates with pH less than 5.5 could contribute to a positive balance of A1 during PD.

Impairment of the mental status of patients on regular dialysis treatment.

The purpose of this study was to assess the mental status of 42 patients on regular dialysis treatment (RDT) by using the Wechsler Adult Intelligence Scale (WAIS) and Wechsler Memory Scale (WMS). Findings were correlated with serum aluminium levels, PTH levels, residual renal function (RRF) and duration of RDT. An impairment of neuropsychological performance related to the duration of RDT was found. However, a possible role of PTH and of absence of RRF could not be excluded. These observations suggest that standard haemodialysis strategies are not able to prevent pathological changes in the brain of uraemic patients.

[Indirect immunoelectrophoresis in the study of urinary proteins]. / L'immunoelettroforesi indiretta nello studio delle proteine urinarie.

The indirect immunoelectrophoresis applied to the proteinurias is a simple and quick method, of usual execution, that makes use of not concentrated urines and discriminant between physiological and pathological proteinurias. The results obtained from a various casistic, collected in many years are presented. For the correlation which exist between morphological isototype and immunoelectropherogram, sometimes, it is possible to go up to the diagnosis of nephropathy also without applying to the renal biopsy.