Document Detail

Effect of β-blocker cessation on chronotropic incompetence and exercise tolerance in patients with advanced heart failure.
MedLine Citation:
PMID:  22855557     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: Chronotropic incompetence is defined as the inability to reach 80% of heart rate (HR) reserve or 80% of the maximally predicted HR during exercise. The presence of chronotropic incompetence is associated with reduced peak oxygen consumption, and rate-responsive pacing therapy is under investigation to improve exercise capacity in heart failure (HF). However, uncertainty exists about whether chronotropic incompetence and reduced exercise tolerance in HF are attributable to β-blockade.
METHODS AND RESULTS: Subjects with HF and receiving long-term β-blocker therapy underwent cardiopulmonary exercise tolerance testing under 2 conditions in random sequence: (1) after a 27-hour washout period (Off-BB) and (2) 3 hours after β-blocker ingestion (On-BB). Norepinephrine levels were drawn at rest and at peak exercise. β1-response to norepinephrine was assessed using the chronotropic responsiveness index: ΔHR/Δlog norepinephrine. Nineteen patients with systolic HF (left ventricular ejection fraction, 22.8±7.7%) were enrolled. Mean age was 49.4±12.3 years. Average carvedilol equivalent dose was 29.1±17.0 mg daily. Peak HR off/on β-blockers was 62.7±18.7% and 51.4±18.2% HR reserve (P<0.01) and 79.1±11.0% and 70.3±12.3% maximally predicted HR (P<0.01). For the Off-BB and On-BB conditions, the respiratory exchange ratios were 1.05±0.06 and 1.05±0.10 (P=0.77), respectively, confirming maximal and near identical effort in both conditions. The peak oxygen consumption was 16.6±3.34 and 15.9±3.31 mL/kg/min (P=0.03), and the chronotropic responsiveness index was 19.3±7.2 and 16.2±7.1 (P=0.18).
CONCLUSIONS: Acute β-blocker cessation does not normalize the chronotropic response to exercise in patients with advanced HF and chronotropic incompetence.
Benjamin J Hirsh; Andrea Mignatti; A Reshad Garan; Nir Uriel; Paolo Colombo; Daniel B Sims; Ulrich P Jorde
Related Documents :
9018497 - Delay time adjustments to minimize errors in breath-by-breath measurement of vo2 during...
15705537 - The independently fractal nature of respiration and heart rate during exercise under no...
3556377 - Ventilatory effects of inhaled capsaicin in man.
20630807 - Can slow breathing exercises improve seizure control in people with refractory epilepsy...
10827007 - Training does not protect against exhaustive exercise-induced lactate transport capacit...
11448707 - Feeling your body or feeling badly: evidence for the limited validity of the somatosens...
Publication Detail:
Type:  Journal Article; Randomized Controlled Trial; Research Support, N.I.H., Extramural     Date:  2012-08-01
Journal Detail:
Title:  Circulation. Heart failure     Volume:  5     ISSN:  1941-3297     ISO Abbreviation:  Circ Heart Fail     Publication Date:  2012 Sep 
Date Detail:
Created Date:  2012-09-19     Completed Date:  2012-12-03     Revised Date:  2013-05-28    
Medline Journal Info:
Nlm Unique ID:  101479941     Medline TA:  Circ Heart Fail     Country:  United States    
Other Details:
Languages:  eng     Pagination:  560-5     Citation Subset:  IM    
Cardiovascular Division, Columbia University Medical Center, New York, NY 10032, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Adrenergic beta-Antagonists / administration & dosage*
Analysis of Variance
Biological Markers / blood
Bisoprolol / administration & dosage
Carbazoles / administration & dosage
Drug Administration Schedule
Exercise Test
Exercise Tolerance / drug effects*
Heart Failure / blood,  diagnosis,  drug therapy*,  physiopathology
Heart Rate / drug effects*
Metoprolol / administration & dosage
Middle Aged
New York City
Norepinephrine / blood
Oxygen Consumption / drug effects
Propanolamines / administration & dosage
Prospective Studies
Respiration / drug effects
Time Factors
Grant Support
Reg. No./Substance:
0/Adrenergic beta-Antagonists; 0/Biological Markers; 0/Carbazoles; 0/Propanolamines; 0K47UL67F2/carvedilol; 37350-58-6/Metoprolol; 51-41-2/Norepinephrine; 66722-44-9/Bisoprolol

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

Previous Document:  In Vivo cMyBPC Gene Transfer Rescues Myofilament Contractile Dysfunction in cMyBPC Null Mice.
Next Document:  Meiotic DNA joint molecule resolution depends on Nse5-Nse6 of the Smc5-Smc6 holocomplex.