PMID- 12740509
OWN - NLM
STAT- MEDLINE
DCOM- 20030903
LR  - 20171101
IS  - 0025-7931 (Print)
IS  - 0025-7931 (Linking)
VI  - 70
IP  - 2
DP  - 2003 Mar-Apr
TI  - Airflow limitation and breathing strategy in congestive heart failure patients 
      during exercise.
PG  - 137-42
AB  - BACKGROUND: Congestive heart failure (CHF) patients experience dyspnea on 
      exertion and therefore have decreased exercise tolerance. OBJECTIVE: This study 
      explores the hypothesis that stable New York Heart Association (NYHA) class III 
      CHF patients without a history of pulmonary disease exhibit airflow limitation 
      with increasing exercise. METHODS: We characterized flow limitations and 
      breathing reserves at baseline, during exercise before anaerobic threshold 
      (pre-AT), and after anaerobic threshold (post-AT) in CHF patients and normal 
      subjects. Data were collected in the form of maximal flow volume loops and 
      subsequent tidal flow volume loops at baseline and during exercise. Expiratory 
      flow limitation was expressed as percent of tidal volume that corresponded with 
      overlap of the tidal flow volume loops and maximal flow volume loops during 
      expiration. The area directly between the maximum flow volume loops and the tidal 
      flow volume loops during the expiratory phase is expressed as expiratory flow 
      volume reserve (EFVR). RESULTS: CHF patients experienced expiratory flow 
      limitation during exercise (pre-AT and post-AT) that was significantly increased 
      compared to baseline and to normal subjects at similar exercise levels (CHF, 
      baseline 8.5 +/- 7, pre-AT 37 +/- 10, post-AT 38 +/- 8%, n = 9, p < 0.05). Both 
      CHF patients and normal subjects increased EFVR during exercise, but only the 
      normal subjects increased EFVR to a significantly different value at post-AT 
      exercise levels (normal subjects, 9.5 +/- 2, 11 +/- 2, 32 +/- 4%, n = 7, p < 
      0.05). Both CHF patients and normal subjects increased end inspiratory lung 
      volume (EILV) during exercise, but only the normal subjects significantly 
      increased EILV at post-AT exercise levels (normal subjects, 49 +/- 4, 55 +/- 5, 
      76 +/- 4%, p < 0.05). Inspiratory capacity (IC)/forced vital capacity (FVC) 
      ratios were increased in CHF patients compared to normal subjects. However, 
      IC/FVC values did not change during exercise in either group. CONCLUSIONS: CHF 
      patients cannot utilize their full respiratory capacity during exercise secondary 
      to expiratory flow limitation and an inability to increase EILV and EFVR.
CI  - Copyright 2003 S. Karger AG, Basel
FAU - Schroeder, C Andrew
AU  - Schroeder CA
AD  - Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California 
      90048, USA. schroederc@cshs.org
FAU - Balfe, David L
AU  - Balfe DL
FAU - Khan, Steven S
AU  - Khan SS
FAU - Mohsenifar, Zab
AU  - Mohsenifar Z
LA  - eng
PT  - Journal Article
PL  - Switzerland
TA  - Respiration
JT  - Respiration; international review of thoracic diseases
JID - 0137356
SB  - IM
CIN - Respiration. 2003 Mar-Apr;70(2):133-4. PMID: 12740507
MH  - Exercise/*physiology
MH  - Exercise Tolerance/physiology
MH  - Female
MH  - Forced Expiratory Flow Rates
MH  - Forced Expiratory Volume
MH  - Heart Failure/*physiopathology
MH  - Humans
MH  - Male
MH  - Middle Aged
MH  - *Respiratory Mechanics
EDAT- 2003/05/13 05:00
MHDA- 2003/09/04 05:00
CRDT- 2003/05/13 05:00
PHST- 2001/10/23 00:00 [received]
PHST- 2002/08/05 00:00 [accepted]
PHST- 2003/05/13 05:00 [pubmed]
PHST- 2003/09/04 05:00 [medline]
PHST- 2003/05/13 05:00 [entrez]
AID - 70059 [pii]
AID - 10.1159/000070059 [doi]
PST - ppublish
SO  - Respiration. 2003 Mar-Apr;70(2):137-42. doi: 10.1159/000070059.