Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1988-12-6
pubmed:abstractText
The cause of the fall in left ventricular (LV) stroke volume (SV) during a fall in pleural pressure (Pp1) has been in dispute for over a century. We have defined the changes in the temporal relationship between LV inflow (Qm) and outflow (Qa) in a canine preparation to test the mutually exclusive hypotheses that the fall in LVSV is caused only by changes during diastole (e.g., ventricular interdependence) or only by changes during systole (e.g., afterload). The ability of the experimental preparation to measure the results of acute changes in right heart volume or output and acute changes in LV afterload was validated in open-chest studies with and without pericardial constraint. In closed-chest studies, with a fall in Pp1 during a Mueller maneuver Qm reached both its inspiratory minimum and expiratory maximum before Qa in 80% of the Mueller maneuvers, invalidating both hypotheses, which each required that one flow lead the other in 100% of the Mueller maneuvers. Review of individual records suggested that if the rapid changes in Pp1 occurred during systole, Qa could vary in a manner independent of the preceding Qm. These studies suggest that both diastolic and systolic events may contribute to the fall in SV, while causing opposite changes in LV volumes.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
8750-7587
pubmed:author
pubmed:issnType
Print
pubmed:volume
65
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1662-75
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Effects of changes in left ventricular loading and pleural pressure on mitral flow.
pubmed:affiliation
Department of Anesthesiology and Critical Care Medicine, Johns Hopkins Hospital, Baltimore, Maryland 21205.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.