Document Detail

Coronary flow reserve in the newborn lamb: an intracoronary Doppler guide wire study.
MedLine Citation:
PMID:  14630989     Owner:  NLM     Status:  MEDLINE    
Recent studies indicate a severely reduced coronary flow reserve (CFR) in neonates with congenital heart disease. The significance of these studies remains debatable, as the ability of the anatomically normal neonatal heart to increase coronary flow is currently unknown. This study was designed to establish normal values for CFR in newborns after administration of adenosine [pharmacologic CFR (pCFR)] and as induced by acute hypoxemia (reactive CFR). Thirteen mechanically ventilated newborn lambs were studied. Coronary flow velocities were measured in the proximal left anterior descending coronary artery before and after adenosine injection (140 and 280 microg/kg i.v.) using an intracoronary 0.014-in Doppler flow-wire. Measurements were made at normal oxygen saturation (SaO(2)) and during progressive hypoxemia induced by lowering the fraction of inspired oxygen. CFR was defined as the ratio of hyperemic to basal average peak flow velocity. In a hemodynamically stable situation with normal SaO(2), pCFR was 3.0 +/- 0.5. pCFR decreased with increasing hypoxemia. Regression analysis showed a linear relation between SaO(2) and pCFR (R = 0.86, p < 0.0001). Reactive CFR obtained at severe hypoxemia (Sao(2) <30%) was 4.2 +/- 0.8, and no significant further increase in coronary flow velocity occurred by administration of adenosine. Newborn lambs have a similar capacity to increase coronary flow in response to both pharmacologic and reactive stimuli as older subjects. Administration of adenosine does not reveal the full capacity of the newborn coronary circulation to increase flow, however, as the flow increase caused by severe hypoxemia is significantly more pronounced.
Gylfi Oskarsson; Erkki Pesonen; Saemunder Gudmundsson; Jónas Ingimarsson; Staffan Sandström; Olof Werner
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2003-11-19
Journal Detail:
Title:  Pediatric research     Volume:  55     ISSN:  0031-3998     ISO Abbreviation:  Pediatr. Res.     Publication Date:  2004 Feb 
Date Detail:
Created Date:  2004-01-22     Completed Date:  2004-09-03     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  0100714     Medline TA:  Pediatr Res     Country:  United States    
Other Details:
Languages:  eng     Pagination:  205-10     Citation Subset:  IM    
Department of Pediatrics, Divison of Pediatric Cardiology, Lund University Hospital, S-221 85 Lund, Sweden.
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MeSH Terms
Acute Disease
Adenosine / pharmacology
Animals, Newborn
Anoxia / drug therapy,  physiopathology*,  ultrasonography*
Carbon Dioxide / blood
Coronary Circulation / drug effects,  physiology*
Disease Models, Animal
Oxygen / blood
Ultrasonography, Doppler*
Ultrasonography, Interventional*
Vasodilator Agents / pharmacology
Reg. No./Substance:
0/Vasodilator Agents; 124-38-9/Carbon Dioxide; 58-61-7/Adenosine; 7782-44-7/Oxygen

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

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