Document Detail


Coronary flow reserve in severe aortic valve stenosis: a positron emission tomography study.
MedLine Citation:
PMID:  18695425     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVES: The purpose was to test whether, in patients with severe aortic stenosis, impaired myocardial blood flow reserve is dependent on myocardial hypertrophy and may improve after valve replacement. METHODS: Fifteen patients with severe aortic stenosis, normal coronary arteries and normal left ventricular systolic function (ejection fraction>50%) underwent a resting/dipyridamole (0.56 mg/kg over 4 min) N-NH3 flow positron emission tomography study and a resting 2D echocardiogram before and 12 months after (eight patients) surgery. Myocardial blood flow reserve was defined as dipyridamole/resting mean myocardial blood flow ratio. RESULTS: Before surgery, the transvalvular maximal pressure gradient was 86+/-19 mmHg, valve area 0.82+/-0.24 cm and left ventricular mass index 185+/-37 g/m. As compared with a positron emission tomography population of normal subjects, patients had a normal resting myocardial blood flow (1.02+/-0.34 vs. 1.04+/-0.22, not significant), a depressed dipyridamole myocardial blood flow (1.58+/-0.69 vs. 3.67+/-0.86, P<0.001) and myocardial blood flow reserve (1.54+/-0.39 vs. 3.63+/-0.97, P<0.001). After surgery, left ventricular mass index decreased (172+/-47 to 118+/-40, P<0.01) but no change was found in resting myocardial blood flow, dipyridamole myocardial blood flow and myocardial blood flow reserve. There was no correlation between flow values and pressure gradient or left ventricular mass index, before or after valve replacement and in pooled data from the two studies. CONCLUSION: In severe aortic stenosis, myocardial blood flow reserve is depressed independent of myocardial hypertrophy and transvalvular pressure gradient. Removal of pressure overload by valve replacement is not able to improve myocardial perfusion.
Authors:
Clara Carpeggiani; Danilo Neglia; Umberto Paradossi; Lorenza Pratali; Mattia Glauber; Antonio L'Abbate
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Journal of cardiovascular medicine (Hagerstown, Md.)     Volume:  9     ISSN:  1558-2027     ISO Abbreviation:  J Cardiovasc Med (Hagerstown)     Publication Date:  2008 Sep 
Date Detail:
Created Date:  2008-08-12     Completed Date:  2008-11-04     Revised Date:  2009-05-28    
Medline Journal Info:
Nlm Unique ID:  101259752     Medline TA:  J Cardiovasc Med (Hagerstown)     Country:  United States    
Other Details:
Languages:  eng     Pagination:  893-8     Citation Subset:  IM    
Affiliation:
Cardiology Department, CNR Institute of Clinical Physiology, Pisa, Italy. clara@ifc.cnr.it
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MeSH Terms
Descriptor/Qualifier:
Aged
Aortic Valve / surgery*
Aortic Valve Stenosis / physiopathology,  radionuclide imaging,  surgery*,  ultrasonography
Coronary Circulation* / drug effects
Dipyridamole / pharmacology
Echocardiography, Doppler
Female
Heart Valve Prosthesis Implantation*
Humans
Male
Middle Aged
Positron-Emission Tomography*
Vasodilator Agents / pharmacology
Chemical
Reg. No./Substance:
0/Vasodilator Agents; 58-32-2/Dipyridamole
Comments/Corrections
Comment In:
J Cardiovasc Med (Hagerstown). 2008 Sep;9(9):869-71   [PMID:  18695421 ]

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