Document Detail


CRT improves the exercise capacity and functional reserve of the failing heart through enhancing the cardiac flow- and pressure-generating capacity.
MedLine Citation:
PMID:  16377239     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: While information on how cardiac resynchronisation therapy (CRT) affects cardiac performance at rest is readily available, the mechanisms whereby CRT alters cardiac function during maximal exercise are unclear.
AIMS: We examined the medium-term effects of CRT on cardiac and physical functional reserve of patients with severe heart failure (CHF) and prolonged QRS duration.
METHODS: Seventeen consecutive patients with severe CHF (NYHA III-IV) and widened QRS underwent maximal cardiopulmonary exercise testing with non-invasive central haemodynamic measurements before and 6-8 weeks after CRT pacemaker implantation.
RESULTS: After CRT there were significant increases in exercise cardiac output by 19.3% (P=0.0048) from 9.5+/-3.4 l min(-1), peak mean arterial blood pressure by 14.1% (P=0.0001) from 91.3+/-13.6 mm Hg, and peak cardiac power output by 37.2% (P=0.0008) from 1.92+/-0.74 W. There were no significant changes in these variables at rest. Exercise duration (+42.3%, P=0.0002), NYHA functional class (P=0.0001) and SF-36 symptom score (P=0.0006) were also significantly improved. Powerful surrogate indicators of prognosis were also significantly improved with CRT: peak O(2) consumption (+20.9%, P=0.0007), VE/VCO(2) slope (-20.0%, P=0.005) and circulatory power (+42.0%, P=0.0012).
CONCLUSION: In this cohort of patients, post-implant CRT significantly improved the flow-, pressure- and power-generating capacity of the failing hearts. This may be causally related to the improvements observed in exercise capacity, functional class and symptom scores.
Authors:
D Schlosshan; D Barker; C Pepper; G Williams; C Morley; L-B Tan
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Publication Detail:
Type:  Journal Article     Date:  2005-12-27
Journal Detail:
Title:  European journal of heart failure     Volume:  8     ISSN:  1388-9842     ISO Abbreviation:  Eur. J. Heart Fail.     Publication Date:  2006 Aug 
Date Detail:
Created Date:  2006-08-18     Completed Date:  2006-12-12     Revised Date:  2011-06-08    
Medline Journal Info:
Nlm Unique ID:  100887595     Medline TA:  Eur J Heart Fail     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  515-21     Citation Subset:  IM    
Affiliation:
Molecular Cardiovascular Medicine, University of Leeds, Leeds General Infirmary, Great George Street, Leeds LS1 3EX, UK.
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MeSH Terms
Descriptor/Qualifier:
Aged
Cardiac Output
Cardiac Pacing, Artificial*
Exercise Test
Exercise Tolerance*
Female
Follow-Up Studies
Health Status Indicators
Heart Failure / physiopathology*,  therapy*
Heart Rate
Humans
Male
Middle Aged
Oxygen Consumption
Pacemaker, Artificial
Prospective Studies
Quality of Life
Vascular Resistance

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


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