Six-Minute Walk Test Distance Predicts Peak VO2 in Patients Supported with Left Ventricular Assist Devices

2.50
Hdl Handle:
http://hdl.handle.net/10755/303944
Category:
Abstract
Type:
Presentation
Title:
Six-Minute Walk Test Distance Predicts Peak VO2 in Patients Supported with Left Ventricular Assist Devices
Author(s):
Prichard, Roslyn A.; Hayward, Christopher S.; Walker, Robyn M.; Juul, Marcus; Davidson, Patricia Mary
Lead Author STTI Affiliation:
Non-member
Author Details:
Roslyn A. Prichard, RN, BA, Grad Dip CCU/ICU, rprichard@stvincents.com.au; Christopher S. Hayward, BMedSc, MBBS, MD, FRACP, FCANZ, MD; Robyn M. Walker, MN, RN, CTcert, DipApSci, BHSci; Marcus Juul, BSc; Patricia Mary Davidson, RN, BA, MEd, PhD, FRCNA;
Abstract:

Session presented on: Friday, July 26, 2013

Purpose: To examine the correlation between six minute walk test distance (6MWTD) and peak VO2 results in patients supported with Left Ventricular Assist Devices.  Two algorithms from the literature which predict VO2 max from 6MWTD in heart failure, are tested for validity in this group. 

Methods: We studied eight  patients supported with VentrAssist LVAD pumps. Each patient underwent 3 days of testing that included a 6MWT and cardiopulmonary test at Normal, High or Low speed. Data sets included,

  1. The distance achieved at each visit and pump speed, paired with the corresponding VO2 max result.
  2. The VO2 Max predicted from 6MWT using  the Cahalin et al algorithm.
  3. The VO2 max predicted from 6MWT using the Maldono-Martin et al algorithm.
  4. Resting left ventricular end diastolic dimensions (LVEDD)
  5. Resting serum Pro BNP levels.

24 data pairs were examined for  correlation between 6MWD and VO2 Max using linear regression. Student T Tests were used to examine the significance of differences in  Left Ventricular end diastolic dimensions and Pro BNP amongst patients who demonstrated response to increasing pump speed and non-responders.  Bland Altman plots established how well the equations of Cahalin and Maldonado-Martin predicted our VO2 max results.

Results:  There was a significant relationship between VO2 max and 6MWT distance (r2=0.32, p=0.004). However In subjects who showed a concomitant increase or decrease in VO2 Max with changing pump speed, there was no relationship found between VO2 and 6MWD.

Conclusion: 6MWD correlates significantly with VO2 Max in LVAD supported patients. Correlation increases when subjects with higher resting Pro BNP levels and larger LVEDDs are excluded. The Cahalin regression equations derived from, transplant wait listed patients, tended to overestimate VO2 Max in  LVAD patients. While the Maldonado-Martin equation overestimated VO2 Max in LVAD subjects with a lower VO2 Max.

Keywords:
TYPE NEW KEYWORD HERE; Left Ventricular assist device; TYPE NEW KEYWORD HERE
Repository Posting Date:
22-Oct-2013
Date of Publication:
22-Oct-2013
Conference Date:
2013
Conference Name:
24th International Nursing Research Congress
Conference Host:
Sigma Theta Tau International, the Honor Society of Nursing
Conference Location:
Prague, Czech Republic
Description:
24th International Nursing Research Congress Theme: Bridge the Gap Between Research and Practice Through Collaboration. Held at the Hilton Prague Hotel.
Note:
This is an abstract-only submission. If the author has submitted a full-text item based on this abstract, you may find it by browsing the Virginia Henderson Global Nursing e-Repository by author. If author contact information is available in this abstract, please feel free to contact him or her with your queries regarding this submission.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_GB
dc.type.categoryAbstracten_GB
dc.typePresentationen_GB
dc.titleSix-Minute Walk Test Distance Predicts Peak VO2 in Patients Supported with Left Ventricular Assist Devicesen_GB
dc.contributor.authorPrichard, Roslyn A.en_GB
dc.contributor.authorHayward, Christopher S.en_GB
dc.contributor.authorWalker, Robyn M.en_GB
dc.contributor.authorJuul, Marcusen_GB
dc.contributor.authorDavidson, Patricia Maryen_GB
dc.contributor.departmentNon-memberen_GB
dc.author.detailsRoslyn A. Prichard, RN, BA, Grad Dip CCU/ICU, rprichard@stvincents.com.au; Christopher S. Hayward, BMedSc, MBBS, MD, FRACP, FCANZ, MD; Robyn M. Walker, MN, RN, CTcert, DipApSci, BHSci; Marcus Juul, BSc; Patricia Mary Davidson, RN, BA, MEd, PhD, FRCNA;en_GB
dc.identifier.urihttp://hdl.handle.net/10755/303944-
dc.description.abstract<p>Session presented on: Friday, July 26, 2013</p><b>Purpose: </b> To examine the correlation between six minute walk test distance (6MWTD) and peak VO2 results in patients supported with Left Ventricular Assist Devices.  Two algorithms from the literature which predict VO2 max from 6MWTD in heart failure, are tested for validity in this group.  <p><b>Methods: </b> We studied eight  patients supported with VentrAssist LVAD pumps. Each patient underwent 3 days of testing that included a 6MWT and cardiopulmonary test at Normal, High or Low speed. Data sets included, <ol> <li>The distance achieved at each visit and pump speed, paired with the corresponding VO2 max result.</li> <li>The VO2 Max predicted from 6MWT using  the Cahalin et al algorithm.</li> <li>The VO2 max predicted from 6MWT using the Maldono-Martin et al algorithm.</li> <li>Resting left ventricular end diastolic dimensions (LVEDD)</li> <li>Resting serum Pro BNP levels.</li> </ol><p><span lang="EN-US">24 data pairs were examined for  correlation between 6MWD and VO2 Max using linear regression. Student T Tests were used to examine the significance of differences in  Left Ventricular end diastolic dimensions and Pro BNP amongst patients who demonstrated response to increasing pump speed and non-responders.  </span>Bland Altman plots established how well the equations of Cahalin and Maldonado-Martin predicted our VO2 max results. <p><b>Results: </b><b> </b>There was a significant relationship between VO2 max and 6MWT distance (r<sup>2</sup>=0.32, p=0.004). However In subjects who showed a concomitant increase or decrease in VO2 Max with changing pump speed, there was no relationship found between VO2 and 6MWD. <p><b>Conclusion: </b> 6MWD correlates significantly with VO2 Max in LVAD supported patients. Correlation increases when subjects with higher resting Pro BNP levels and larger LVEDDs are excluded. The Cahalin regression equations derived from, transplant wait listed patients, tended to overestimate VO2 Max in  LVAD patients. While the Maldonado-Martin equation overestimated VO2 Max in LVAD subjects with a lower VO2 Max.en_GB
dc.subjectTYPE NEW KEYWORD HEREen_GB
dc.subjectLeft Ventricular assist deviceen_GB
dc.subjectTYPE NEW KEYWORD HEREen_GB
dc.date.available2013-10-22T20:26:21Z-
dc.date.issued2013-10-22-
dc.date.accessioned2013-10-22T20:26:21Z-
dc.conference.date2013en_GB
dc.conference.name24th International Nursing Research Congressen_GB
dc.conference.hostSigma Theta Tau International, the Honor Society of Nursingen_GB
dc.conference.locationPrague, Czech Republicen_GB
dc.description24th International Nursing Research Congress Theme: Bridge the Gap Between Research and Practice Through Collaboration. Held at the Hilton Prague Hotel.en_GB
dc.description.noteThis is an abstract-only submission. If the author has submitted a full-text item based on this abstract, you may find it by browsing the Virginia Henderson Global Nursing e-Repository by author. If author contact information is available in this abstract, please feel free to contact him or her with your queries regarding this submission.en_GB
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