The Clinical Evaluation of Faulty Orthostatic Mechanisms

Idiopathic Orthostatic Hypotension

“…After tilting to 40°, cardiac output, blood pressure, stroke volume as well as circulating blood volume decreased without any significant change in heart rate or total peripheral resistance. These findings were in ac cordance with previous data obtained in idiopathic orthostatic hypotension [3,10,13,23,25,29,38], Recently, in patients with autonomic insufficiency, significantly low cardiac index was found [26].…”

“…According to several authors, the absence of orthostatic increase in circulating catechol amines, in certain cases even a decrease, is characteristic of idiopathic or thostatic hypotension [20,22,24,25,28], However, as could be anticipated from previous investigations [4,10,31,33,42], the patient showed a defi nite hypersensitivity to exogenous norepinephrine both in the horizontal and in the tilted position. In fact, this so-called 'denervation hypersensitivity' is one of the main arguments which speak in favor of a generalized desympathetized state as the basic pathological alteration in idiopathic or thostatic hypotension.…”

Distinctive abnormal responses to tilting test in chronic chagas' disease

“…These changes are induced by the aortic and carotid baroreceptor response to the initial fall in blood pressure, resulting in a reflex adrenergic stimulation of the vessels and acceleration of the heart rate [13]. The efferent limb of these reflexes is mediated by adrenergic fibers of the autonomic nervous system through the release of norepinephrine in the vessel wall [6]. Our results demonstrate that (a) all chagasic patients with or without heart failure respond to the upright tilting with a significantly smaller rise in diastolic pressure than do normal subjects; (b) chagasic patients with heart failure have a significantly lower heart rate than normal subjects and especially lower when compared with non-chagasic heart failure patients and (c) diastolic changes of blood pressure during the 5 min of passive upright tilting did not show significant differences between Groups I and II chagasic patients and the non-chagasic heart failure group.…”

“…The purpose of this study was, therefore, to investigate the sympathetic nervous system function in patients with chronic Chagas' disease from an endemic area, assessing it by means of the cardiovascular response to the tilting test [6][7] with special attention to heart rate and diastolic blood pressure [8].…”

Hemodynamics in Shy-Drager Syndrome and Treatment with Indomethacin

“…The standing test was performed as to meet the diagnostic criteria for orthostatic hypoten sion proposed by Hicklerel al. [4], The blood pressure of 156/113 mm Hg in a supine position dropped markedly to 62/54 mm Hg, immediately after tilting. The reproducibility of the standing test was good in this patient.…”