Document Detail


Impact of Tachycardia and Sympathetic Stimulation by Cold Pressor Test on Cardiac Diastology and Arterial Function in Elderly Females.
MedLine Citation:
PMID:  23355342     Owner:  NLM     Status:  Publisher    
Abstract/OtherAbstract:
Abnormal vascular-ventricular coupling has been suggested to contribute to heart failure with preserved ejection fraction in elderly females. Failure to increase stroke volume (SV) during exercise occurs in parallel with dynamic changes in arterial physiology leading to increased afterload. Such adverse vascular reactivity during stress may reflect either sympatho-excitation or be due to tachycardia. We hypothesized that afterload elevation induces SV failure by transiently attenuating left ventricular (LV) relaxation, a phenomenon described in animal research. The respective roles of tachycardia and sympatho-excitation were investigated in n = 28 elderly females (70±4 years) carrying permanent pacemakers. At rest, during atrial tachycardia pacing (ATP; 100 • min(-1)) and during cold pressor test (CPT; hand immersed in iced water), we performed Doppler echocardiography (UR(MAX): maximal untwist rate analyzed by speckle tracking imaging of rotational mechanics) and arterial tonometry (arterial stiffness estimated as augmentation index: AI(X)). Estimation of arterial compliance was based on an exponential relationship between arterial pressure and volume. We found that ATP produced central hypovolemia and a reduction in SV which was larger in patients with stiffer arteries (higher AI(X)). There was an associated adverse response of arterial compliance and vascular resistance during ATP and CPT, causing an overall increase in afterload, but nonetheless enhanced UR(MAX) and no evidence of afterload-dependent failure of relaxation. In conclusion, tachycardia and cold provocation in elderly females produces greater vascular reactivity and SV failure in the presence of arterial stiffening, but SV failure does not arise secondary to afterload-dependent attenuation of relaxation.
Authors:
Jonas Johnson; Felicia Håkansson; Kambiz Shahgaldi; Aristomenis Manouras; Mikael Norman; Anders Sahlén
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2013-1-25
Journal Detail:
Title:  American journal of physiology. Heart and circulatory physiology     Volume:  -     ISSN:  1522-1539     ISO Abbreviation:  Am. J. Physiol. Heart Circ. Physiol.     Publication Date:  2013 Jan 
Date Detail:
Created Date:  2013-1-28     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100901228     Medline TA:  Am J Physiol Heart Circ Physiol     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Affiliation:
1Royal Institute of Technology.
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