In nine healthy subjects, cold stimuli were administered to the forehead and hand, to the oral and nasal cavities via ice cubes and to the bronchial system via inhalation of cold air (−25 • C). Blood pressure, heart rate and muscle sympathetic nerve activity (MSNA) from the peroneal nerve were recorded. MSNA expressed as total activity increased during cold air inhalation, cooling of the forehead (P < 0.001, ANOVA), hand and mouth (P ≤ 0.05), paralleled by a rise in blood pressure during cold air inhalation and cooling of the forehead and hand (P < 0.01). Cooling of the forehead provoked a faster increase of MSNA expressed as total activity (P < 0.05) and higher levels of diastolic blood pressure (P = 0.05) compared with cooling of the hand. Bradycardia was observed only during cooling of the nasal cavity (P < 0.001) and the forehead (P < 0.05). It is concluded that cooling of the skin and mucous membranes of the tracheobronchial tract elicits sympathetically mediated hemodynamic adaptations, probably via stimulation of cold-sensitive afferents.

Severe acute cardiogenic pulmonary edema (ACPE) can successfully be treated with noninvasive pressure support ventilation (NIPSV) in a clinical setting. Whether prehospital NIPSV starting early at patients' home and being continued until hospital arrival is feasible and improves ACPE emergency care is examined in this study. End points of the study were oxygen saturation at hospital admission and clinical outcome. Twenty-three patients suffering from severe cardiac pulmonary edema with severe dyspnea, an oxygen saturation of less than 90% and basal rales were included in this controlled prospective randomized trial. All patients received standard medical treatment and 10 patients were additionally treated with NIPSV (pressure support level, 12 cmH2O; positive endexpiratory pressure, 5 cmH2O; FiO2, 0.6) whereas the other patients received oxygen (8 l/min) via Venturi face mask. Improvement in oxygen saturation was significantly faster in the NIPSV group and oxygen saturation was higher at the time of the hospital admission (NIPSV=97.3+/-0.8%; standard=89.5+/-2.7%, P=0.002). A trend toward higher troponin T levels was seen in the standard treatment group. The need for intensive care treatment did not differ, and one patient of each treatment group died in hospital. No complications were noted during the treatment with NIPSV. Prehospital NIPSV is feasible and able to improve emergency management of ACPE.

Objectives. The aim of the study was to investigate the resting levels of novel cardiovascular biomarkers in common types of noncardiac syncope.Design and setting. An observational study was conducted including 255 patients (mean age 60 years, range 15-93; 45% men) with unexplained syncopal attacks. Subjects underwent an expanded head-up tilt test including carotid sinus massage, and nitroglycerin provocation if indicated. Using logistic regression, we explored the associations between specific diagnoses of syncope and resting levels of circulating biomarkers: C-terminal pro-arginine vasopressin (CT-proAVP), C-terminal endothelin-1 precursor fragment (CT-proET-1), midregional fragments of pro-atrial natriuretic peptide (MRproANP) and pro-adrenomedullin (MR-proADM).Results. A total of 142 (56%) patients were diagnosed with vasovagal syncope (VVS), 85 (33%) with orthostatic hypotension (OH) and 47 (18%) with carotid sinus hypersensitivity (CSH); in addition, 74 (29%) patients had more than one diagnosis. Thirty-five patients (14%) demonstrated a cardioinhibitory reflex. The probability of VVS was highest in the first quartile of MR-proANP [Q1 vs. Q4: odds ratio (OR) 5.57, 95% confidence interval (CI) 1.86-16.74; P < 0.001] and CT-proET-1 (OR 7.17, 95% CI 2.43-21.13; P < 0.001). By contrast, the probability of OH was highest in the fourth quartile of CT-proET-1 (Q4 vs. Q1: OR 8.66, 95% CI 2.49-30.17; P < 0.001). Furthermore, CSH was most frequently observed in the first quartile of MRproANP (Q1 vs. Q4: OR 6.57, 95% CI 1.62-26.62; P = 0.008) among those over 60 years of age, whereas the cardioinhibitory reflex was strongly associated with low CT-proET-1 levels (Q1 vs. Q4: OR 69.7, 95% CI 6.97-696.6; P < 0.001). Moreover, in patients with VVS, a high concentration of CT-proET-1 was predictive of OH (OR per 1 SD 2.4, 95% CI 1.15-5.02; P = 0.02), whereas low CTproET-1 suggested involvement of the cardioinhibitory reflex (OR per 1SD 0.42, 95% CI 0.25-0.70; P = 0.001).Conclusions. The levels of MR-proANP and CT-proET-1 are markedly changed in common forms of syncope, suggesting the involvement of novel neurohormonal mechanisms in syncopal attacks.

Selective ANG II receptor blockade not only decreases blood pressure, but also shifts the baroreflex set-point for the initiation of counter-regulatory reflex responses of heart rate and blood pressure towards normal blood pressure levels. Thus, data suggest that ANG II plays a pathogenetic role in the elevation of the baroreflex set point in primary hypertensive subjects.

Abstract-That sleep is accompanied by a blood pressure decrease is well known; however, the underlying physiology deserves further investigation. The present study examines in healthy subjects 2 main questions: is this dipping actively evoked? and what are the consequences of nondipping for daytime blood pressure? Nocturnal blood pressure was extrinsically elevated in 12 sleeping subjects to mean daytime values by continuously infused phenylephrine. This nondipping significantly lowered morning blood pressure during rest and 3 hours after resuming physical activity compared with a control condition (isotonic saline). Neither muscle sympathetic nerve activity nor sensitivity of ␣-adrenoceptors was reduced. However, the set point for initiation of regulatory responses through the baroreflex was clearly shifted toward lower blood pressure levels. Our results support the hypothesis of an actively regulated central mechanism for blood pressure resetting and set point consolidation of the baroreflex during nighttime sleep. This is suggested by the fact that extrinsically induced nondipping induces sustained decrease in blood pressure during the following morning through an actively lowered baroreflex set point. (Hypertension.

Subjects born too small for their gestational age show a significantly lower sympathetic nerve activity under baseline conditions. Given the different baseline values, the sympathetic response to haemodynamic alteration is not affected in LBW subjects, and maximal activation during non-haemodynamic sympatho-excitatory manoeuvres is preserved.

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