Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1989-11-7
pubmed:abstractText
The birth process is associated with dramatic alterations of left ventricular (LV) volume loading, pressure loading, and contractile state. The preterm LV has considerable volume loading reserve. We have assessed neuroendocrine and related hemodynamic responses of the preterm lamb LV at 0.8 gestation during acute pressure loading within the first 2-4 h after birth. We measured plasma catecholamines and hemodynamic and cineangiocardiographic parameters of LV pump performance and contractility at basal levels and during rapid LV pressure loading by partial balloon obstruction of the ascending aorta before and after propranolol. A relatively high level of propranolol (3 mg/kg) was required to produce beta-adrenoceptor blockade associated with reduction of heart rate and blood pressure, but after atrial pacing there was no detectable difference of basal LV pump performance or contractility at comparable heart rate, preload, and afterload. The LV pump performance was maintained and plasma catecholamines and LV contractility were increased when aortic systolic pressure was augmented 60% over baseline. The increased contractile state at greater afterload was minimally blunted by propranolol. Thus the preterm LV is relatively hypercontractile soon after birth and is capable of an integrated augmentation of pump performance and contractile state during pressure loading. These findings are relevant to the maintenance of adequate LV performance and successful adaptation to the acute alterations of afterload associated with the transitional circulation at birth.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0031-3998
pubmed:author
pubmed:issnType
Print
pubmed:volume
26
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
336-42
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Hemodynamic and neuroendocrine adaptations of the preterm lamb left ventricle to acutely increased afterload.
pubmed:affiliation
Department of Pediatrics, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey 17033.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't