Linked Life Data

1936024

Source:http://linkedlifedata.com/resource/pubmed/id/1936024

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1991-12-26
pubmed:abstractText
It is generally believed that mitral regurgitation (MR) creates a systolic 'unloading' effect by providing a low-resistance ejection into the left atrium; this is thought to increase the left ventricular ejection fraction (EF), and thus to mask a reduced contractile state. Similarly, mitral valve replacement (MVR), by removing the low-resistance regurgitant leak, has been thought to increase left ventricular afterload (systolic wall stress) and thereby cause the decrease in EF that is often seen postoperatively. These concepts have never been confirmed in patients with chronic MR. Accordingly, we evaluated systolic wall stress before and after MVR and assessed stress-shortening relations in two groups of patients with chronic MR (those with compensated and those with decompensated MR). Calculated values for circumferential and meridional wall stress were found to be normal or high in patients with chronic MR. This indicates that chronic MR is not associated with an unloading effect. In decompensated MR, systolic wall stress tends to increase after MVR; this can contribute to a postoperative decline in myocardial fibre shortening and a lower EF. By contrast, patients with compensated MR exhibit a decline in systolic wall stress after MVR; despite this postoperative decline in afterload, fibre shortening falls. This indicates that the fall in fibre shortening after MVR is not the result of increased systolic loading. In such patients, the valve replacement (with loss of integrity of papillary muscles and chordae, and a tethering of posterobasal wall motion by the prosthesis) is most likely responsible for the postoperative decline in fibre shortening and EF.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0195-668X
pubmed:author
pubmed:issnType
Print
pubmed:volume
12 Suppl B
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
48-51
pubmed:dateRevised
2005-11-16
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Left ventricular function after surgical correction of chronic mitral regurgitation.
pubmed:affiliation
Department of Medicine, Medical Center of Central Massachusetts, Worcester.
pubmed:publicationType
Journal Article, Review