Hu, Sharon X H and Keogh, Anne M and Macdonald, Peter S and Kotlyar, Eugene and Robson, Desiree and Harkess, Michelle and Granger, Emily and Dhital, Kumud and Jansz, Paul and Spratt, Phillip and Hayward, Christopher S (2013) Interaction between physical activity and continuous-flow left ventricular assist device function in outpatients. Journal of cardiac failure, 19 (3). pp.169-75. ISSN 1532-8414 (Not OA)
Full text not available from this repository.Abstract
OBJECTIVE
Studies have shown that pump output by continuous-flow left ventricular assist devices (LVADs) increases with graded exercise testing. However, data on pump behavior during activities of daily living and sleep, where cardiac output requirements vary markedly, are lacking. We sought to determine pump parameters and activity levels in stable patients receiving outpatient LVAD therapy.
METHODS AND RESULTS
Eleven outpatients (mean age 51 ± 14 years, 9 male) with centrifugal continuous-flow LVADs underwent monitoring of LVAD flow, heart rate (HR), energy expenditure, and physical activity over 1 week in an outpatient setting. Physical activity was recorded with the use of a combined pedometer, accelerometer, and calorimeter Sensewear armband. Pump, HR, and physical activity parameters were time matched for correlation analysis. Outpatients had an average pump flow of 5.67 ± 1.27 L/min and engaged predominately in low levels of physical activity (mean daily step count 3,249/day). Across the entire cohort, pump flow exhibited strong univariate relationships with patients' energy expenditure (r = 0.73), step count (r = 0.69), HR (r = 0.73), sleep (r = -0.89), and skin temperature (r = -0.85; P < .0001 for all). Multivariate analysis suggested that pump output was predominantly affected by recumbent position, energy expenditure and skin temperature (r(2) = 0.84; P < .0001). Pump flow and power consumption were significantly lower during sleep than during wake periods (5.48 ± 1.31 L/min vs 5.80 ± 1.26 L/min; P < .001).
CONCLUSIONS
Pump output from continuous-flow LVADs is adaptive to changes in activities of daily living. Circadian variation in pump flow is mostly explained by recumbency and activity levels. Despite adequate pump flow, many LVAD patients continue to live sedentary lifestyles.
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| Item Type: | Article |
|---|---|
| Subjects: | R Medicine > R Medicine (General) |
| Depositing User: | Repository Administrator |
| Date Deposited: | 06 Jan 2016 23:06 |
| Last Modified: | 11 Mar 2016 04:57 |
| URI: | https://eprints.victorchang.edu.au/id/eprint/122 |
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