Document Detail

Sympathetic stimulations by exercise-stress testing and by dobutamine infusion induce similar changes in heart rate variability in patients with chronic heart failure.
MedLine Citation:
PMID:  7554756     Owner:  NLM     Status:  MEDLINE    
1. Heart rate variability can be used to evaluate autonomic balance, but it is unclear how inotropic therapy may affect the findings. The aim of the study was to assess whether heart rate variability can differentiate between sympathetic stimulation induced by inotrope infusion or by physical exercise. 2. Ten patients with chronic heart failure (64.3 +/- 5.4 years of age) underwent four dobutamine infusions (8-min steps of 5 micrograms min-1 kg-1) and four supine bicycle exercise tests (5-min steps of 25 W). Plasma noradrenaline was evaluated, as well as the SD of R-R intervals, together with low-frequency (0.03-0.14 Hz) and high-frequency (0.15-0.4 Hz) components of heart rate variability using autoregressive spectral analysis. 3. Exercise and inotrope infusion produced similar changes in heart rate variability. An exercise load of 50 W and a dobutamine infusion of 15 micrograms min-1 kg-1 gave the following results respectively: heart rate, 120.3 +/- 3.0 beats/min versus 110.2 +/- 3.0 beats/min; SD, 16.0 +/- 1.1 ms versus 16.3 +/- 2.5 ms; low-frequency component, 4.3 +/- 0.3 ln-ms2 versus 4.4 +/- 0.3 ln-ms2 and high-frequency component, 2.6 +/- 0.3 ln-ms2 versus 2.2 +/- 0.3 ln-ms2. All comparisons were nonsignificant. The variables of heart rate variability showed high reproducibility in the same subject during different conditions. Noradrenaline was elevated by exercise from 326.0 +/- 35.2 pg/ml to 860.1 +/- 180.4 pg/ml (P < 0.05), but was unchanged by dobutamine infusion. 4. Heart rate variability changes cannot differentiate between dobutamine infusions and physical exercise, indicating that we should be cautious in evaluating patients undergoing inotropic therapy. The degree of receptor stimulations, rather than the level of sympathetic drive, would appear to determine the changes in heart rate variability.
M Piepoli; S Adamopoulos; L Bernardi; P Sleight; A J Coats
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Publication Detail:
Type:  Clinical Trial; Controlled Clinical Trial; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Clinical science (London, England : 1979)     Volume:  89     ISSN:  0143-5221     ISO Abbreviation:  Clin. Sci.     Publication Date:  1995 Aug 
Date Detail:
Created Date:  1995-11-03     Completed Date:  1995-11-03     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  7905731     Medline TA:  Clin Sci (Lond)     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  155-64     Citation Subset:  IM    
Department of Cardiovascular Medicine, John Radcliffe Hospital, Oxford, U.K.
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MeSH Terms
Blood Pressure / physiology
Chronic Disease
Cross-Over Studies
Dobutamine / pharmacology*
Exercise / physiology
Exercise Test
Heart Failure / physiopathology*
Heart Rate / drug effects,  physiology*
Middle Aged
Reproducibility of Results
Sympathetic Nervous System / physiopathology*
Reg. No./Substance:

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