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Query: UMLS:C0848237 (acute stress)
 4,619 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hemodynamic responses to acute stress exposure were studied in normotensive control (C) and chronically sympathectomized (S) rats. Male Sprague-Dawley rats received daily sc injections of either saline (C) or guanethidine (S) from 1 to 13 weeks of age. Doppler flow probes were then implanted for the measurement of blood velocity in the sub-diaphragmatic aorta, superior mesenteric artery and distal aorta (hindquarters). After 10 days of recovery and 24 hours before the study, the caudal artery was cannulated. In the conscious freely moving rats, mean arterial pressure (MAP), heart rate (HR) and indices of regional blood flows and vascular conductances (G as blood flow/MAP ratio) were recorded beat to beat, before and during emotional stress (jet of air for 2 min). In basal conditions, mean values of MAP and HR were similar in C (107 +/- 2 mmHg; 399 +/- 8 bpm, n = 9) and S (106 +/- 3 mmHg; 384 +/- 12 bpm, n = 7) rats. The effects of stress on MAP, HR, aortic (AoG), mesenteric (MeG) and hindquarters (HqG) vascular conductances are expressed as percentage changes from baseline (delta): [table: see text] These results highlight the role of vascular sympathetic nerves in pressor responses and systemic and mesenteric vasoconstrictions induced by stress in the rat. They also indicate that vasodilatation in the hindquarters vascular bed is not secondary to withdrawal of sympathetic vasoconstrictor tone but rather to active phenomena which do not involve the stimulation of vascular beta 2-adrenoceptors by neuronal catecholamines nor the release of vasodilator cotransmitters from the sympathetic nerve endings.
Arch Mal Coeur Vaiss 1992 Aug
PMID:[Role of sympathetic nerve fibers in hemodynamic responses to stress in rats]. 148 48

The implantable automatic defibrillator has completely changed the prognosis of potentially fatal ventricular arrhythmias by the delivery of an electric shock in the event of ventricular tachycardia or fibrillation. This vital device is sometimes poorly accepted from the psychological point of view by patients having been traumatised by experiences of sudden death from which they have been rescuscitated. Anxiety and depression are common and they have an important effect on the quality of life. The unpredictable occurrence of painful, multiple and uncontrollable electrical shocks may induce a state of acute stress with stunning, the resemblance of which to the model of learned helplessness described experimentally in the animal by Seligman, is discussed. The authors report the case of a 20 year old man whose automatic defibrillator was activated twenty times in one night. His state of stress and impotence was such that he lay prostate in his bed. Suicide seemed to be the only possible way of escaping from the electrical shocks of the device which was perceived as being dangerous. The management of this condition is not standardised but it requires the collaboration of the cardiac rhythmological and psychiatric teams. Medication with antidepressant drugs alone is not sufficient. The regulation of the sensitivity of the defibrillator gives the patient a feeling of mastering the situation: submission is not total! Research along this line should improve the patients' acceptation of the device and their quality of life.
Arch Mal Coeur Vaiss 2003 Dec
PMID:[Psychiatric complication of an implanted automatic defibrillator]. 1524 53