Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In order to analyze the respiratory, cardiovascular, and ECG responses to acute hypoxic hypoxia, three experimental series were carried out in a randomized manner on 11 healthy, unacclimatized volunteers at rest during standardized stepwise exposure to 6000 m (PAO2 35.2 +/- 2.9 mmHg/4.7 +/- 0.4 kPa) in a low-pressure chamber a) without (control), b) with propranolol, and c) with atropine combined with propranolol. The results show that hypoxic hyperventilation and alveolar gases are not affected by activation of the sympatho-adrenal axis or by parasympathetic withdrawal. Sympathetic activity, however, increases heart rate, stroke volume (pulse pressure), estimated cardiac output and systolic blood pressure, whereas decreased parasympathetic activity increases heart rate and estimated cardiac output, but lowers stroke volume. The fall in peripheral resistance, observed during progressive hypoxia in all three groups, is thought to be due to hypoxia-induced depression of the vasomotor center. At altitude catecholamine secretion and vagal withdrawal synergistically account in the ECG for the R-R shortening, the relative Q-T lengthening, the elevation of the P wave and the ST-T flattening. Probable direct hypoxic effects on the heart are the increase in P-Q duration and the minor but still significant depression of the T wave. It is concluded that at altitude increased sympatho-adrenal and decreased parasympathetic activity is without effect on hypoxic hyperventilation, but accounts for most of the cardiovascular and ECG changes. Diminution of sympathetic activity and imminent vagotonia arising after acute ascent to 6000 m probably reflect hypoxia of the central nervous system.
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PMID:Effects of atropine and propranolol on the respiratory, circulatory, and ECG responses to high altitude in man. 334 81

Results showed that autonomic nervous system (ANS) and blood circulation system (BCS) dysfunction in 3rd trimester pregnant women with gestosis are more pronounced, than in healthy pregnant women, despite the prescribed treatment. The most significant disturbances were vagotonia and hypokinetic haemodynamics type (often iatrogenic). Spinal anaesthesia (SA) during Cesarean section in pregnant women is accompanied by blood pressure decrease to the level demanding on vasopressors use. Considering normal indicators of SI, CI, oxygen transportation and electrocardiogram vasopressor was not introduced Apgar score assessment of newborns was within normal. However, vagotonia and hypokinetic haemodynamics type during anaesthesia that certifies autoregulation reserves insufficiency. Atropine introduction in pregnant women with vagotonia and hypokinetic haemodynamics type (often iatrogenic, owing to irrational therapy) before SA beginning of promoted neurovegetative inhibition optimization and haemodynamics stabilization in eukinetic range. Vagus blockade (elimination of ANS dysfunction) was accompanied by more physiologic sympathicotonia development with smaller decrease of blood pressure (without stroke index reduction!), absence of bradycardia and vomiting. Research showed that the blood pressure cannot be the only objective criterion of vasopressors use.
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PMID:[Neuro-autonomic inhibition and haemodynamics management optimization during cesarean section under spinal anaesthesia in pregnant women with gestosis]. 2366 21