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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: OBJECTIVE, MATERIALS AND METHODS, RESULT. Meshes: Aged, Blood Flow Velocity, Echocardiography, Doppler, Color, Female, Humans, Male, Middle Aged, Renal Dialysis, Reproducibility of Results, Sensitivity and Specificity, Uremia, Ventricular Dysfunction, Left.
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Color M-mode flow propagation velocity: is it really preload independent? Context: This study investigates the change in flow propagation velocity (FPV) in uremic patients who undergo regular hemodialysis (H/D). We studied 93 uremic patients (44 men and 49 women; 59 +/- 14-years-old) receiving regular hemodialysis. Patients were separated by baseline left ventricular ejection fraction (LVEF): 71 patients with LVEF>50% (group 1), 13 patients with LVEF 35-50% (group 2), 7 patients with LVEF<35% (group 3). All patients were in sinus rhythm before H/D. They received complete transthoracic echocardiographic examinations. Flow propagation velocity was measured by color M-mode echocardiography in apical four chambers view. All these parameters were obtained before and after H/D. Paired data were compared. According to different H/D amounts, we viewed the FPV response after H/D in variant baseline LVEF groups. The baseline FPV became lower in patients with low LVEF. After H/D, obvious decrement of FPV occurred in group 1, but there were no obvious changes in groups 2 and 3. In fact, a slight increment of FPV was found in group 3. In patients with baseline LVEF>50%, FPV after H/D was almost always lower, regardless of H/D amount. But there was different response in patients with baseline LVEF<50%.
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Flow propagation velocity is preload independent in patients with LVEF<50%, but it is preload-dependent in patients with LVEF>50%.