Linked Life Data

7769156

Source:http://linkedlifedata.com/resource/pubmed/id/7769156

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1995-6-30
pubmed:abstractText
The aim of this study was to evaluate the sympatho-vagal interaction modulating cardiovascular function and the possible impairment of baroreceptor sensitivity in patients affected by Pure Autonomic Failure (PAF). We studied 4 patients affected by PAF and 7 controls at rest and during different levels (45 degrees, 60 degrees, 90 degrees) of head-up tilt. On a different day all subjects underwent i.v. administration of phenylephrine at dosages adequate to enhance systolic blood pressure by about 20 mmHg both at rest and during 45 degrees head-up tilt. Finally, 1.5 mg atropine was infused intravenously only in the patients. Spectral analysis of RR interval and systolic arterial pressure (SAP) variabilities provided markers of sympathetic (low-frequency oscillations, about 0.1 Hz, LFRR) and vagal (high-frequency oscillations, about 0.25 Hz, HFRR) modulations of heart period and of sympathetic vasomotor activity (low-frequency oscillations of SAP variability, LFSAP). Baroreceptor mechanisms were quantified by means of the index alpha (calculated from the square root of the ratio between the powers of HF components of RR interval and SAP variabilities) and of the phenylephrine RR-SAP slope. Patients affected by PAF were characterized by a drastic decrease in total power of RR variability and by the absence of LFRR and LFSAP components. Moreover, HFRR, although largely predominant in its relative value, was also markedly reduced in its absolute value. Finally, the baroreceptive mechanisms appeared to be heavily impaired. In conclusion, PAF patients seem to be characterized by a complex alteration of neural mechanisms, which in addition to the signs of a sympathetic denervation include an impairment, at least functional, of the vagal modulation of heart rate.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0165-1838
pubmed:author
pubmed:issnType
Print
pubmed:day
2
pubmed:volume
51
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
223-35
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Pure Autonomic Failure: complex abnormalities in the neural mechanisms regulating the cardiovascular system.
pubmed:affiliation
Centro Ricerche Cardiovascolari, CNR, Milano, Italy.
pubmed:publicationType
Journal Article, Clinical Trial