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Uremic cardiomyopathy in chronic hemodialysis patients. |
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Background. Echocardiographic abnormalities present frequently in chronic hemodialysis patients. Changes of left ventricular (LV) size, shape, or function are present in between 70 and 80% of dialysis patients. LV abnormalities may be manifested as concentric LV hypertrophy, LV dilation with or without LV hypertrophy or systolic dysfunction. LV hypertrophy in dialysis patients is independently associated with higher subsequent mortality rates, as, in the general population, in patients with essential hypertension, and in patients with coronary artery disease. In dialysis patients, high cavity volume and low contractility are also associated with higher mortality. Objectives. The goal of the the study was to define the spectrum of LV geometry changes and reveal the factors associated with these changes in chronic hemodialysis patients. Materials and Methods. This study was performed at the in the Dialysis and Detoxicology Department of the Central University Clinic, in 1997. 50 hemodialysis patients who survived at least 6 months from the start of ESRD therapy entered the study. At baseline and at yearly intervals thereafter, a clinical assessment was undertaken to detect risk factors for cardiovascular diseases. Echocardiography was performed by the use of M-mode and two-dimensional ultrasonography, carried out, where possible, when the patient had achieved dry weight, the day after a dialysis treatment in hemodialysis patients. Left ventricular mass indexes (LVMI) were indexed to body surface area and were presented in grams per square meter. Clinical and laboratory data were obtained monthly or annually during follow – up. Discussion and Conclusions: LV dilation, which becomes less reversible with time, seems to be the most characteristic morphological pattern and commonly observed in hemodialysis patients. Cardiac enlargement was associated with increased risks of developing ischemic heart disease and cardiac failure in this population. Thus, in dialysis patients echocardiographic classification system depends much more on LV cavity volume which highly prevalence in patients starting renal replacement therapy. This pattern of geometry changes are not always connected with classic hemodinamic stress, such as hypertension and anemia. Some forms of these abnormalities suggest to be connected with uremic internal environment, that has direct effect on cardiac size, shape, and function. The best clinical evidence is the observation that LV hypertrophy, LV dilation, and especially systolic disfunction improve after renal transplantation. Comparatively little is known about the prognostic effect of these abnormalities, although there is evidence to suggest that LV dilated cardiomyopathy is one of the markers of poor prognosis in this population. |
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