Clinical autonomic research : official journal of the Clinical Autonomic Research Society
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Clinical Trial
Prolonged latency in the baroreflex mediated vascular resistance response in subjects with postural related syncope.
In addition to the gain, the delay of the baroreflex response plays an important role in the maintenance of cardiovascular system stability. Additionally when postural changes induce sudden drops in blood pressure, a delayed response may fail to maintain sufficient cerebral perfusion pressure. We tested the hypothesis that the delay of the carotid baroreceptor reflex is impaired in subjects with poor orthostatic tolerance. ⋯ The results following baroreceptor loading were more scattered. The early fainters still had a tendency to show prolonged latency. These results suggest that the delay in the baroreflex response plays an important role in postural related syncope.
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Imprecise definitions of syncope and related conditions appear common in the medical literature. To investigate the scope of the problem we systematically searched for definitions in high-ranking medical journals. ⋯ Syncope and related conditions proved to be infrequently and inconsistently defined in current medical literature. The lack of consistent terminology is likely to harm medical education, research, and patient care. There is a strong need for a systematic terminology for syncope and related conditions.
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Sympathetic testing was carried out in patients in the acute phase of "complex regional pain syndrome type I" (CRPS I) shortly after trauma to the upper limb. Repeated measurements were used to detect changes in peripheral sympathetic function during the course of the disease. ⋯ Sympathetic dysfunction is regularly seen at the onset of CRPS I and normalizes during the course of the disease. This temporary phenomenon suggests a posttraumatic sympathetic deficit playing a decisive role in the genesis of CRPS I.
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Urinary incontinence is the inability to willingly control bladder voiding. Stress urinary incontinence (SUI) is the most frequently occurring type of incontinence in women. No widely accepted or approved drug therapy is yet available for the treatment of stress urinary incontinence. ⋯ In cats, whose bladder had initially been irritated with acetic acid, a dose-dependent improvement of the bladder capacity (5-fold) and periurethral EMG activity (8-fold) of the striated sphincter muscles was found. In a double blind, randomized, placebo-controlled, clinical trial in women with stress urinary incontinence, there was a significant reduction in urinary incontinence episodes under duloxetine treatment. In summary, the pharmacological effect of duloxetine to increase the activity of the striated urethral sphincter together with clinical results indicate that duloxetine has an interesting therapeutic potential in patients with stress urinary incontinence.
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Clinical Trial
Stroke volume monitored by modeling flow from finger arterial pressure waves mirrors blood volume withdrawn by phlebotomy.
Rate-controlled blood withdrawal was used to reduce cardiac preload and consequently stroke volume in patients with normal cardiac function. Twelve patients with asymptomatic hereditary hemochromatosis, undergoing regular phlebotomy therapy, volunteered for the study. An average volume of 375 ml was withdrawn in an average period of 6.4 min. ⋯ Beat-to-beat analysis demonstrated a significant linear regression between most of the hemodynamic indices and the volume withdrawn. The highest correlation coefficients were found for the stroke volume (0.88 +/- 0.01, P < 0.001) and the pulse pressure (0.80 +/- 0.04, P < 0.001) corresponding also to the highest slopes for the lines relating these measures to the relative blood volume withdrawn. The non-invasive estimation of finger blood pressure can be used to derive simple on-line indices (pulse pressure, stroke volume using the Modelflow) of cardiac preload, which are of major interest in the monitoring of cardiovascular status.