Hypovolemia explains the reduced stroke volume at altitude
نویسندگان
چکیده
منابع مشابه
Hypovolemia explains the reduced stroke volume at altitude
During acute altitude exposure tachycardia increases cardiac output (Q) thus preserving systemic O2 delivery. Within days of acclimatization, however, Q normalizes following an unexplained reduction in stroke volume (SV). To investigate whether the altitude-mediated reduction in plasma volume (PV) and hence central blood volume (CBV) is the underlying mechanism we increased/decreased CBV by mea...
متن کاملArterial pulse pressure and its association with reduced stroke volume during progressive central hypovolemia.
BACKGROUND The reduction of stroke volume (SV) during hemorrhage reflects the degree of blood loss, but accurate assessment of SV in bleeding patients in the field currently is not possible. In a previous pilot study, we reported that arterial pulse pressure and estimated sympathetic nerve activity (SNA) in trauma patients who died of hemorrhagic injuries was significantly lower than that obser...
متن کاملEvidence that reduced skeletal muscle recruitment explains the lactate paradox during exercise at high altitude.
THE STUDIES of Amann et al. (1, 2) provide the final evidence necessary to solve the “lactate paradox” that has haunted the exercise sciences since first described in 1936 (4) and which was the recent focus of a Point:Counterpoint debate (25, 26). In its simplest form the paradox describes the finding of lower than expected blood lactate concentrations during maximal exercise at altitude, espec...
متن کاملCommentaries on viewpoint: evidence that reduced skeletal muscle recruitment explains the lactate paradox during exercise at high altitude.
TO THE EDITOR: Noakes (5) and other authors have proposed that central motor command (CMC) and, consequently, exercise performance in hypoxia is determined by the following. 1) By simple negative feedback (1, 2) or complex feedback/ feedforward (4) subconscious homeostatic control systems that, based on afferent information from central and peripheral chemoreceptors, limit skeletal muscle recru...
متن کاملLast word on viewpoint: evidence that reduced skeletal muscle recruitment explains the lactate paradox during exercise at high altitude.
TO THE EDITOR: Surely the art of science is to see the complete picture. Some respondents focus on the findings that peak blood lactate concentrations and muscle activation are reduced in hypoxia and ignore the related phenomenon that exercise in hypoxia terminates at low cardiac outputs and blood lactate concentrations. I provided a unifying explanation for these phenomena. Dr. Marcora (see Re...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Physiological Reports
سال: 2013
ISSN: 2051-817X
DOI: 10.1002/phy2.94