| Relationship between double product break point, lactate threshold, and ventilatory threshold in cardiac patients. | |
| | |
MedLine Citation:
|
PMID: 14566565 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
A double product break point (DPBP) occurs simultaneously with both ventilatory threshold (VT) and lactate threshold (LT) in normal subjects. We sought to determine whether a DPBP also occurs in cardiac patients and to investigate correlations between DPBP, VT and LT (study 1). We also evaluated a non-invasive DPBP measurement system that determined blood pressure automatically by the cuff method (study 2). Study 1 comprised 15 patients [8 men and 7 women, mean (SD) age 47.7 (11.1) years] who performed cardiopulmonary exercise tests on a cycle ergometer. The double product was defined as the product of heart rate and direct systolic blood pressure. Arterial blood samples were obtained for measurement of lactate, pyruvate, pH, and norepinephrine levels. VT was determined by gas analysis, and LT was determined as the lactate/pyruvate ratio. DPBPs were detected in all 15 patients. Double product slopes above the DPBP were significantly greater than those below the DPBP (286.2 vs 98.5/W, P<0.001). The lactate/pyruvate ratio increased, arterial pH decreased, and plasma norepinephrine concentration increased above the DPBP. DPBP had strong positive correlations with VT ( r=0.93) and LT ( r=0.95). Study 2 comprised 65 cardiac patients. The DPBP was detected in 89.2% of patients and correlated closely with VT. We conclude that DPBP occurs near VT and LT in cardiac patients during incremental exercise, that the noninvasive DPBP measurement method is comparable to the invasive method, and that DPBP may be as useful an index of exercise intensity in patients with cardiac disease as VT or LT. |
| | |
Authors:
|
Kazuto Omiya; Haruki Itoh; Naomi Harada; Tomoko Maeda; Akihiko Tajima; Keiko Oikawa; Akira Koike; Tadanori Aizawa; Long-Tai Fu; Naohiko Osada |
Related Documents
:
|
11796675 - Effects of body posture and tidal volume on inter- and intraregional ventilation distri... 6881685 - Interactions among behavioral style, ventilatory drive, and load recognition. 6863095 - Changes in relaxation rate with diaphragmatic fatigue in humans. 2694765 - Effects of continuous positive- and negative-pressure breathing on the pattern of breat... 7078665 - Selective additive effect of phenylephrine to the inotropic action of isoproterenol on ... 22488185 - Lower extremity neuromuscular control immediately after fatiguing hip-abduction exercise. |
Publication Detail:
|
Type: Clinical Trial; Comparative Study; Journal Article; Validation Studies Date: 2003-10-18 |
Journal Detail:
|
Title: European journal of applied physiology Volume: 91 ISSN: 1439-6319 ISO Abbreviation: Eur. J. Appl. Physiol. Publication Date: 2004 Mar |
Date Detail:
|
Created Date: 2004-03-01 Completed Date: 2004-10-19 Revised Date: 2007-11-15 |
Medline Journal Info:
|
Nlm Unique ID: 100954790 Medline TA: Eur J Appl Physiol Country: Germany |
Other Details:
|
Languages: eng Pagination: 224-9 Citation Subset: IM |
Affiliation:
|
The Cardiovascular Institute, 7-3-10 Roppongi, Minato-ku, Tokyo 106-0032, Japan. omiya@marianna-u.ac.jp |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Adult Anaerobic Threshold* Blood Pressure* Cardiovascular Diseases / diagnosis*, physiopathology* Exercise Test / methods* Female Heart Rate* Humans Lactic Acid / blood* Male Middle Aged Reproducibility of Results Sensitivity and Specificity Statistics as Topic |
| Chemical | |
Reg. No./Substance:
|
50-21-5/Lactic Acid |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Modulation of H reflexes in the forearm during voluntary teeth clenching in humans.
Next Document: Limitation of muscle deoxygenation in the triceps during incremental arm cranking in women.