Previous reports suggest that inflammatory bowel diseases may be accompanied by abnormalities in the neural autonomic profile. We tested the hypotheses that 1) an exaggerated sympathetic activity characterizes active ulcerative colitis (UC) and 2) a reduction of sympathetic activity by clonidine would be associated with clinical changes of UC. In 23 patients with UC and 20 controls, muscle sympathetic nerve activity (MSNA), ECG, blood pressure, and respiration were continuously recorded, and plasma catecholamine was evaluated both at rest and during a 75 degrees head-up tilt. Autonomic profile was assessed by MSNA, norepinephrine, epinephrine, spectral markers of low-frequency (LF) cardiac sympathetic (LF(RR); normalized units) and high-frequency (HF) parasympathetic (HF(RR); normalized units) modulation and sympathetic vasomotor control (LF systolic arterial pressure; LF(SAP)), obtained by spectrum analysis of the R-R interval and systolic pressure variability. Among UC patients, 16 agreed to be randomly assigned to 8-wk transdermal clonidine (15 mg/wk, 9 subjects), or placebo (7 patients). An autonomic profile, Disease Activity Index (DAI), and endoscopic pattern were compared before and after clonidine/placebo. At rest, MSNA, heart rate (HR), LF(RR), LF/HF, and LF(SAP) were higher and HF(RR) was lower in patients than in controls. Tilt decreased HF(RR) and increased MSNA and LF(RR) less in patients than in controls. Clonidine decreased HR, MSNA, epinephrine, LF(RR), and increased HF(RR), whereas placebo had no effects. Changes of the autonomic profile after clonidine were associated with reduction of DAI score. An overall increase of sympathetic activity characterized active UC. Normalization of the autonomic profile by clonidine was accompanied by an improvement of the disease.

Background and Purpose— Despite treatment with oral anticoagulants, patients with nonvalvular atrial fibrillation (AF) may experience ischemic cerebrovascular events. The aims of this case-control study in patients with AF were to identify the pathogenesis of and the risk factors for cerebrovascular ischemic events occurring during non–vitamin K antagonist oral anticoagulants (NOACs) therapy for stroke prevention. Methods— Cases were consecutive patients with AF who had acute cerebrovascular ischemic events during NOAC treatment. Controls were consecutive patients with AF who did not have cerebrovascular events during NOACs treatment. Results— Overall, 713 cases (641 ischemic strokes and 72 transient ischemic attacks; median age, 80.0 years; interquartile range, 12; median National Institutes of Health Stroke Scale on admission, 6.0; interquartile range, 10) and 700 controls (median age, 72.0 years; interquartile range, 8) were included in the study. Recurrent stroke was classified as cardioembolic in 455 cases (63.9%) according to the A-S-C-O-D (A, atherosclerosis; S, small vessel disease; C, cardiac pathology; O, other causes; D, dissection) classification. On multivariable analysis, off-label low dose of NOACs (odds ratio [OR], 3.18; 95% CI, 1.95–5.85), atrial enlargement (OR, 6.64; 95% CI, 4.63–9.52), hyperlipidemia (OR, 2.40; 95% CI, 1.83–3.16), and CHA 2 DS 2 -VASc score (OR, 1.72 for each point increase; 95% CI, 1.58–1.88) were associated with ischemic events. Among the CHA 2 DS 2 -VASc components, age was older and presence of diabetes mellitus, congestive heart failure, and history of stroke or transient ischemic attack more common in patients who had acute cerebrovascular ischemic events. Paroxysmal AF was inversely associated with ischemic events (OR, 0.45; 95% CI, 0.33–0.61). Conclusions— In patients with AF treated with NOACs who had a cerebrovascular event, mostly but not exclusively of cardioembolic pathogenesis, off-label low dose, atrial enlargement, hyperlipidemia, and high CHA 2 DS 2 -VASc score were associated with increased risk of cerebrovascular events.

Background-Left and right carotid baroreflex afferents participate in generating the spontaneous variability of heart rate (HR), arterial pressure (AP), and muscle sympathetic nerve activity (MSNA), but the relative contribution of each side is unclear. Pathophysiological conditions unilaterally affecting carotid baroreceptor function might result in abnormal changes of HR, AP, and MSNA variability, thus markedly affecting prognosis. We tested the hypothesis that unilateral carotid baroreceptor perturbation might differentially affect HR, AP, and MSNA variability compared with stimulation of the opposite side. Methods and Results-In

Background-Nonhypotensive lower body negative pressure (LBNP) induces a reflex increase in forearm vascular resistance and muscle sympathetic neural discharge without affecting mean heart rate. We tested the hypothesis that a reflex change of the autonomic modulation of heartbeat might arise during low intensity LBNP without changes of mean heart rate. Methods and Results-Ten healthy volunteers underwent plasma catecholamine evaluation and a continuous recording of ECG, finger blood pressure, respiratory activity, and central venous pressure (CVP) during increasing levels of LBNP up to Ϫ40 mm Hg. Spectrum and cross-spectrum analyses assessed the changes in the spontaneous variability of R-R interval, respiration, systolic arterial pressure (SAP), and CVP and in the gain (␣ LF ) of arterial baroreflex control of heart rate. Baroreceptor sensitivity was also evaluated by the SAP/R-R spontaneous sequences technique. LBNP began decreasing significantly: CVP at Ϫ10, R-R interval at Ϫ20, SAP at Ϫ40, and the indexes ␣ LF and baroreceptor sensitivity at Ϫ30 and Ϫ20 mm Hg, compared with baseline conditions. Plasma norepinephrine increased significantly at Ϫ20 mm Hg. The normalized low-frequency component of R-R variability (LF R-R ) progressively increased and was significantly higher than in the control condition at Ϫ15 mm Hg. Conclusions-Nonhypotensive LBNP elicits a reflex increase of cardiac sympathetic modulation, as evaluated by LF R-R , which precedes the changes in the hemodynamics and in the indexes of arterial baroreflex control. (Circulation. 2001;