Journal article
Effect of exercise and pump speed modulation on invasive hemodynamics in patients with centrifugal continuous-flow left ventricular assist devices
The Journal of Heart and Lung Transplantation, Vol.34(4), pp.522-529
2015
PMID: 25662859
Abstract
Background: Continuous-flow left ventricular assist devices (CF-LVADs) improve functional capacity in patients with end-stage heart failure. Pump output can be increased by increased pump speed as well as changes in loading conditions.
Methods: The effect of exercise on invasive hemodynamics was studied in two study protocols. The first examined exercise at fixed pump speed (n = 8) and the second with progressive pump speed increase (n = 11). Patients underwent simultaneous right-heart catheterization, mixed venous saturation, echocardiography and mean arterial pressure monitoring. Before exercise, a ramp speed study was performed in all patients. Patients then undertook symptom-limited supine bicycle exercise.
Results: Upward titration of pump speed at rest (by 11.6 ± 8.6% from baseline) increased pump flow from 5.3 ± 1.0 to 6.3 ± 1.0 liters/min (18.9% increase, p < 0.001) and decreased pulmonary capillary wedge pressure (PCWP; 13.6 ± 5.4 to 8.9 ± 4.1 mm Hg, p < 0.001). Exercise increased pump flow to a similar extent as pump speed change alone (to 6.2 ± 1.0 liters/min, p < 0.001), but resulted in increased right- and left-heart filling pressures (right atrial pressure [RAP]: 16.6 ± 7.5 mm Hg, p < 0.001; PCWP 24.8 ± 6.7 mm Hg, p < 0.001). Concomitant pump speed increase with exercise enhanced the pump flow increase (to 7.0 ± 1.4 liters/min, p < 0.001) in Protocol 2, but did not alleviate the increase in pre-load (RAP: 20.5 ± 8.0 mm Hg, p = 0.07; PCWP: 26.8 ± 12.7 mm Hg; p = 0.47). Serum lactate and NT-proBNP levels increased significantly with exercise.
Conclusions: Pump flow increases with up-titration of pump speed and with exercise. Although increased pump speed decreases filling pressures at rest, the benefit is not seen with exercise despite concurrent up-titration of pump speed.
Details
- Title
- Effect of exercise and pump speed modulation on invasive hemodynamics in patients with centrifugal continuous-flow left ventricular assist devices
- Authors
- Kavitha Muthiah (Author) - UNSW AustraliaDesiree Robson (Author) - St Vincent's Hospital SydneyRoslyn Prichard (Author) - St Vincent's Hospital SydneyRobyn Walker (Author) - St Vincent's Hospital SydneySunil Gupta (Author) - UNSW AustraliaAnne M Keogh (Author) - St Vincent's Hospital SydneyPeter S Macdonald (Author) - St Vincent's Hospital SydneyJohn Woodard (Author) - Ventracor LimitedEugene Kotlyar (Author) - St Vincent's Hospital SydneyKumud Dhital (Author) - St Vincent's Hospital SydneyEmily Granger (Author) - St Vincent's Hospital SydneyPaul Jansz (Author) - St Vincent's Hospital SydneyPhillip Spratt (Author) - St Vincent's Hospital SydneyChristopher S Hayward (Author) - St Vincent's Hospital Sydney
- Publication details
- The Journal of Heart and Lung Transplantation, Vol.34(4), pp.522-529
- Publisher
- Elsevier Inc
- DOI
- 10.1016/j.healun.2014.11.004
- ISSN
- 1557-3117
- PMID
- 25662859
- Organisation Unit
- University of the Sunshine Coast, Queensland; School of Nursing, Midwifery and Paramedicine - Legacy; School of Health - Nursing
- Language
- English
- Record Identifier
- 99512707902621
- Output Type
- Journal article
Metrics
15 Record Views
InCites Highlights
These are selected metrics from InCites Benchmarking & Analytics tool, related to this output
- Collaboration types
- Domestic collaboration
- Web Of Science research areas
- Cardiac & Cardiovascular Systems
- Respiratory System
- Surgery
- Transplantation
UN Sustainable Development Goals (SDGs)
This output has contributed to the advancement of the following goals:
Source: InCites