Document Detail


Evidence supportive of impaired myocardial blood flow reserve at high altitude in subjects developing high-altitude pulmonary edema.
MedLine Citation:
PMID:  18310524     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
An exaggerated increase in pulmonary arterial pressure is the hallmark of high-altitude pulmonary edema (HAPE) and is associated with endothelial dysfunction of the pulmonary vasculature. Whether the myocardial circulation is affected as well is not known. The aim of this study was, therefore, to investigate whether myocardial blood flow reserve (MBFr) is altered in mountaineers developing HAPE. Healthy mountaineers taking part in a trial of prophylactic treatment of HAPE were examined at low (490 m) and high altitude (4,559 m). MBFr was derived from low mechanical index contrast echocardiography, performed at rest and during submaximal exercise. Among 24 subjects evaluated for MBFr, 9 were HAPE-susceptible individuals on prophylactic treatment with dexamethasone or tadalafil, 6 were HAPE-susceptible individuals on placebo, and 9 persons without HAPE susceptibility served as controls. At low altitude, MBFr did not differ between groups. At high altitude, MBFr increased significantly in HAPE-susceptible individuals on treatment (from 2.2 +/- 0.8 at low to 2.9 +/- 1.0 at high altitude, P = 0.04) and in control persons (from 1.9 +/- 0.8 to 2.8 +/- 1.0, P = 0.02), but not in HAPE-susceptible individuals on placebo (2.5 +/- 0.3 and 2.0 +/- 1.3 at low and high altitude, respectively, P > 0.1). The response to high altitude was significantly different between the two groups (P = 0.01). There was a significant inverse relation between the increase in the pressure gradient across the tricuspid valve and the change in myocardial blood flow reserve. HAPE-susceptible individuals not taking prophylactic treatment exhibit a reduced MBFr compared with either treated HAPE-susceptible individuals or healthy controls at high altitude.
Authors:
B A Kaufmann; A M Bernheim; S Kiencke; M Fischler; J Sklenar; H Mairbäurl; M Maggiorini; H P Brunner-La Rocca
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Publication Detail:
Type:  Controlled Clinical Trial; Journal Article     Date:  2008-02-29
Journal Detail:
Title:  American journal of physiology. Heart and circulatory physiology     Volume:  294     ISSN:  0363-6135     ISO Abbreviation:  Am. J. Physiol. Heart Circ. Physiol.     Publication Date:  2008 Apr 
Date Detail:
Created Date:  2008-04-02     Completed Date:  2008-05-29     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:  H1651-7     Citation Subset:  IM    
Affiliation:
Dept. of Cardiology, University Hospital Basel, Petersgraben 4, 4031 Basel, Switzerland.
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MeSH Terms
Descriptor/Qualifier:
Acclimatization
Adult
Altitude
Altitude Sickness / physiopathology,  prevention & control*,  ultrasonography
Carbolines / therapeutic use*
Dexamethasone / therapeutic use*
Double-Blind Method
Exercise
Female
Fractional Flow Reserve, Myocardial / drug effects*
Glucocorticoids / therapeutic use*
Hemodynamics / drug effects*
Humans
Male
Middle Aged
Mountaineering
Phosphodiesterase Inhibitors / therapeutic use*
Pulmonary Edema / physiopathology,  prevention & control*,  ultrasonography
Time Factors
Vasodilation / drug effects
Chemical
Reg. No./Substance:
0/Carbolines; 0/Glucocorticoids; 0/Phosphodiesterase Inhibitors; 0/tadalafil; 50-02-2/Dexamethasone

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