Linked Life Data

3171169

Source:http://linkedlifedata.com/resource/pubmed/id/3171169

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
1988-11-3
pubmed:abstractText
In 62 untreated patients with essential hypertension, arterial baroreflex sensitivity (BRS) for heart rate, i.e. the change in pulse interval in response to a phenylephrine-induced increase in blood pressure, was compared with (1) haemodynamic changes during mental arithmetic, a reaction time test, isometric and bicycle exercise; (2) plasma noradrenaline (PNA) concentrations at rest, and during bicycle exercise and; (3) the variability of ambulatory intra-arterial blood pressure. Subjects with diminished BRS showed the following responses: (1) higher mean arterial blood pressure (MAP) during all four stimuli; (2) a greater pressor response to cycling; (3) tended to have higher PNA concentrations during bicycle exercise and; (4) greater variation in ambulatory blood pressure. Furthermore, an increased pressor response to the reaction time test and increased ambulatory blood pressure variability was seen in younger subjects with reduced BRS. When subjects were subgrouped according to their WHO stage of hypertension, there were significant inverse relationships between BRS and the pressor responses to mental arithmetic, the reaction time test and cycling, and with ambulatory blood pressure variability only in those subjects without ECG or radiographic evidence of left ventricular enlargement (WHO stage I hypertension; n = 42). None of these correlations were present in subjects with one or both of these clinical findings (WHO stage II; n = 20). Pressor responses to the four laboratory stimuli and ambulatory blood pressure variability were similar in both groups, despite significantly higher arterial pressure and significantly lower BRS in WHO stage II subjects. These results suggest that differing mechanisms may be responsible for the regulation of blood pressure variation in these two groups. The arterial baroreflex can buffer acute changes in blood pressure in subjects with WHO stage I hypertension, but this ability is attenuated with progressive reduction of BRS. With the development of clinically evident cardiac adaptation to hypertension (WHO stage II), the contribution of the arterial baroreflex to the regulation of blood pressure is no longer detectable and the influence of cardiac and somatic afferents to reflex circulatory adjustments to activity may predominate.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0263-6352
pubmed:author
pubmed:issnType
Print
pubmed:volume
6
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
525-35
pubmed:dateRevised
2009-9-29
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Consequences of impaired arterial baroreflexes in essential hypertension: effects on pressor responses, plasma noradrenaline and blood pressure variability.
pubmed:affiliation
Department of Cardiovascular Medicine, University of Oxford, John Radcliffe Hospital, Headington, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't