Hayward, Christopher S and Salamonsen, Robert and Keogh, Anne M and Woodard, John and Ayre, Peter and Prichard, Roslyn and Kotlyar, Eugene and Macdonald, Peter S and Jansz, Paul and Spratt, Phillip (2015) Impact of left ventricular assist device speed adjustment on exercise tolerance and markers of wall stress. International Journal of Artificial Organs, 38 (9). pp.501-7. ISSN 1724-6040 (N/A)
Full text not available from this repository.Abstract
INTRODUCTION
Left ventricular assist devices are crucial in rehabilitation of patients with end-stage heart failure. Whether cardiopulmonary function is enhanced with higher pump output is unknown.
METHODS
10 patients (aged 39±16 years, mean±SD) underwent monitored adjustment of pump speed to determine minimum safe low speed and maximum safe high speed at rest. Patients were then randomized to these speed settings and underwent three 6-minute walk tests (6MWT) and symptom-limited cardiopulmonary stress tests (CPX) on separate days.
RESULTS
Pump speed settings (low, normal and high) resulted in significantly different resting pump flows of 4.43±0.6, 5.03±0.94, and 5.72±1.2 l/min (P<.001). There was a significant enhancement of pump flows (greater at higher speed settings) with exercise (P<0.05). Increased pump speed was associated with a trend to increased 6MWT distance (P=.10); and CPX exercise time (p=.27). Maximum workload achieved and peak oxygen consumption were significantly different comparing low to high pump speed settings only (P<.05). N-terminal-pro-B-type natriuretic peptide release was significantly reduced at higher pump speed with exercise (P<.01).
CONCLUSIONS
We have found that alteration of pump speed setting resulted in significant variation in estimated pump flow. The high-speed setting was associated with lower natriuretic hormone release consistent with lower myocardial wall stress. This did not, however, improve exercise tolerance.
| Item Type: | Article |
|---|---|
| Subjects: | R Medicine > R Medicine (General) |
| Depositing User: | Repository Administrator |
| Date Deposited: | 03 Feb 2016 22:29 |
| Last Modified: | 16 Mar 2018 04:12 |
| URI: | https://eprints.victorchang.edu.au/id/eprint/291 |
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