Document Detail


Increased diastolic time fraction as beneficial adjunct of alpha1-adrenergic receptor blockade after percutaneous coronary intervention.
MedLine Citation:
PMID:  18790830     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The effect of alpha1-receptor blockade with urapidil on coronary blood flow and left ventricular function has been attributed to relief of diffuse coronary vasoconstriction following percutaneous coronary intervention (PCI). We hypothesized that an increase in diastolic time fraction (DTF) contributes to the beneficial action of urapidil. In eleven patients with a 63% (SD 13) diameter stenosis, ECG, aortic pressure (Pa) and distal intracoronary pressure (Pd), and blood flow velocity were recorded at baseline and throughout adenosine-induced hyperemia. Measurements were obtained before and after PCI and after subsequent alpha1-receptor blockade with urapidil (10 mg ic). DTF was determined from the ECG and the Pa waveform. Functional parameters such as coronary flow velocity reserve, fractional flow reserve, and an index of hyperemic microvascular resistance (HMR) were assessed. Urapidil administration after PCI induced an upward shift in the DTF-heart rate relationship, resulting in a 3.1% (SD 2.7) increase in hyperemic DTF at a constant heart rate (P < 0.005) due to a shorter duration of systole. Hyperemic Pa and Pd decreased, respectively, by 6.1% (SD 6.6; P < 0.05) and 5.7% (SD 5.8; P < 0.01) after alpha1-blockade. Although epicardially measured functional parameters were on average not altered by alpha1-blockade due to concurrent changes in pressure and heart rate, HMR decreased by urapidil in those patients where coronary pressure remained constant. In conclusion, alpha1-receptor blockade after PCI produced a modest but significant prolongation of DTF at a given heart rate, thereby providing an adjunctive beneficial mechanism for improving subendocardial perfusion, which critically depends on DTF.
Authors:
Christina Kolyva; Bart-Jan Verhoeff; Jos A E Spaan; Jan J Piek; Maria Siebes
Publication Detail:
Type:  Clinical Trial; Journal Article; Research Support, Non-U.S. Gov't     Date:  2008-09-12
Journal Detail:
Title:  American journal of physiology. Heart and circulatory physiology     Volume:  295     ISSN:  0363-6135     ISO Abbreviation:  Am. J. Physiol. Heart Circ. Physiol.     Publication Date:  2008 Nov 
Date Detail:
Created Date:  2008-11-10     Completed Date:  2008-12-22     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100901228     Medline TA:  Am J Physiol Heart Circ Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  H2054-60     Citation Subset:  IM    
Affiliation:
Department of Biomedical Engineering & Physics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
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MeSH Terms
Descriptor/Qualifier:
Adrenergic alpha-Antagonists / therapeutic use*
Aged
Angioplasty, Transluminal, Percutaneous Coronary*
Blood Pressure / drug effects
Combined Modality Therapy
Coronary Circulation / drug effects*
Coronary Stenosis / metabolism,  physiopathology,  therapy*
Diastole / drug effects
Female
Heart Rate / drug effects
Hemodynamics / drug effects*
Humans
Male
Middle Aged
Piperazines / therapeutic use*
Receptors, Adrenergic, alpha-1 / antagonists & inhibitors*,  metabolism
Time Factors
Treatment Outcome
Vascular Resistance / drug effects
Vasodilation / drug effects
Chemical
Reg. No./Substance:
0/Adrenergic alpha-Antagonists; 0/Piperazines; 0/Receptors, Adrenergic, alpha-1; 34661-75-1/urapidil

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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