Document Detail


Calculation of mean arterial pressure during exercise as a function of heart rate.
MedLine Citation:
PMID:  8591100     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Mean arterial blood pressure (MAP) is a common characteristic of the cardiac cycle. Usually it is evaluated by assuming that the left ventricular ejection time (systole) constitutes a constant proportion of the cardiac cycle (i.e. 1/3), regardless of the heart rate (HR). However, elevation of HR during exercise results in a reduction of the duration of the ejection period and even a greater reduction of the ventricular filling period. Therefore, a constant diastole/systole proportion at various heart rates may be misleading. The purpose of this study was therefore to evaluate the accurate proportion of the systolic period from the cardiac cycle at different metabolic rates and calculate MAP accordingly. Twenty healthy subjects (age: 20-50 yr.) exercised at different work intensities on a cycle ergometer to elicit HR in the range of 55-180 bpm. During the ride the mitral and aortic flow velocity wave form were recorded by Doppler echocardiography; the mitral flow from the apical view and the aortic flow from the apical long axis view. Blood pressure was measured using a sphygmomanometer. The fraction of systole (St) from the heart cycle was related to HR and was described in mathematical terms as: St = 0.01exp(4.14-40.74/HR) MAP was then calculated from the diastolic blood pressure (dBP) and the pulse pressure (PP) adjusted for St as follows: MAP = dBP+St.PP; (mmHg) The use of the suggested model reduces errors in the evaluation of various cardiac parameters which are related to arterial pressure, such as peripheral resistance, especially under exercise-heat stress.
Authors:
D Moran; Y Epstein; G Keren; A Laor; J Sherez; Y Shapiro
Publication Detail:
Type:  Clinical Trial; Journal Article    
Journal Detail:
Title:  Applied human science : journal of physiological anthropology     Volume:  14     ISSN:  1341-3473     ISO Abbreviation:  Appl Human Sci     Publication Date:  1995 Nov 
Date Detail:
Created Date:  1996-04-01     Completed Date:  1996-04-01     Revised Date:  2004-11-17    
Medline Journal Info:
Nlm Unique ID:  9506216     Medline TA:  Appl Human Sci     Country:  JAPAN    
Other Details:
Languages:  eng     Pagination:  293-5     Citation Subset:  IM; S    
Affiliation:
Heller Institute of Medical Research, Sheba Medical Center, Tel Hashomer.
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MeSH Terms
Descriptor/Qualifier:
Adult
Blood Pressure*
Exercise / physiology*
Female
Heart Rate*
Humans
Mathematics
Middle Aged
Models, Cardiovascular

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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