Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1981-5-26
pubmed:abstractText
The purpose of this study was to determine whether mid-systolic closure and opening of the aortic valve in patients with hypertrophic obstructive cardiomyopathy (HOCM) may reflect dynamic changes of pressure induced by turbulent blood flow in the aorta and left ventricular outflow tract. Five patients with HOCM who had echocardiographic evidence of mid-systolic closure of the aortic valve and two patients with HOCM who did not have transient mid-systolic closure of the aortic valve were studied. In patients in whom mid-systolic closure was present, a transient mid-systolic drop of pressure was present in the left ventricular outflow tract, distal to the dynamic intraventricular obstruction, 17 +/- 3 mm Hg (mean +/- SEM) and in the root of the aorta, 16 +/- 4 mm Hg. In these patients the mid-systolic drop of pressure was consistently associated with a high-intensity intracardiac murmur indicative of turbulence. In the two patients in whom mid-systolic closure of the aortic valve was absent, the transient mid-systolic drop of pressure during systole was minimal (average, 3 mm Hg). The transient mid-systolic drop of pressure distal to the intraventricular obstruction can be explained on the basis of decreased pressure energy of the blood due to turbulence. Since total energy is conserved, increased kinetic energy due to turbulence occurs at the expense of a loss in pressure energy. The transient mid-systolic reduction of pressure in the turbulent zone during systole may cause a pressure differential across the open valvular leaflets resulting in a transient closure of the aortic valve.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:issn
0098-6569
pubmed:author
pubmed:issnType
Print
pubmed:volume
6
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
397-404
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1980
pubmed:articleTitle
Mid-systolic closure of the aortic valve in hypertrophic obstructive cardiomyopathy: a pressure-related phenomenon induced by turbulent blood flow.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't