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- Myers, T. M., et al.
(author)
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Hemodynamic Evaluation of the Jarvik 2000 Heart During Heart Failure
- 2001
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In: ASAIO journal (1992). - : Wolters Kluwer. - 1058-2916 .- 1538-943X. ; 46:2, s. 167-
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Journal article (peer-reviewed)abstract
- The Jarvik 2000 Heart is an axial flow left ventricular assist system designed for long-term circulatory support. Purpose: To assess the level of hemodynamic support provided by the Jarvik 2000 in an animal model, with acute, severe heart failure. Methods: Heart failure (HF) was induced in 5 calves by progressively ligating the LAD coronary artery. A continuous infusion of esmolol hydrochloride was given to maintain the stability of HF. Compared to normal baseline values, during heart failure CI decreased by 33% (p < 0.02), LAP increased by 16% (p < 0.03), and BP decreased by 28% (p < 0.13). Once stable HF was established, the pump was turned on, and hemodynamic measurements were obtained at pump speed settings that ranged from 8,000 to 12,000 rpm. Results: Selected, mean hemodynamic values are presented in the table, CI, LAP, and BP improved significantly (p < 0.05) at pump speeds >9000 rpm. Pulse pressure (PP) narrowed by 64% (p < 0.009), and the PAP remained unchanged.Image ToolsBlood flow in the femoral artery increased but was not statistically significant. Other hemodynamic parameters such as HR, SVR, PVR, and CVP did not change significantly. Conclusions: The Jarvik 2000 Heart can provide a level of cardiac output support that normalizes the CI and LAP, while maintaining some arterial pressure pulsatility during HF. Systemic perfusion is increased while the left heart is unloaded.
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| 4. |
- Reitan, Öyvind, et al.
(author)
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Initial tests with a new cardiac assist device
- 1999
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In: ASAIO Journal. - 1538-943X. ; 45:4, s. 317-321
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Journal article (peer-reviewed)abstract
- Before, during, and after cardiac intervention, there is occasionally a need for circulatory support because of hemodynamic deterioration. For this purpose, a new minimally invasive cardiac assist device has been developed, and an early prototype has been studied in a bench test and in three pigs. The pump is a catheter system with a distal motor driven propeller (0-15,000 rpm) surrounded by a cage. The catheter was first tested in a tube in a water bath, where efficiency with respect to pressure generation and flow properties was measured. In the pig experiments, the pump was placed in the descending part of the aorta via a graft, and hemodynamic effects were recorded with three different propellers. The bench tests showed a velocity dependent pressure generation in the tube to the second power of the rpm, and 30 cm of water (> 22 mm Hg) could easily be achieved with all propellers. A pressure dependent flow in the tube was observed, with maximum flows of 20 L at 12,000 rpm and 27 L at 15,000 rpm. In the animal experiments, there was a velocity dependent mean pressure difference across the propeller, with up to 48 mm of mercury for the biggest propeller. An increase in cardiac output in all of the pigs was observed as well as a drop in pressure in the proximal part of the aorta. This study demonstrates the efficiency of this new device in vitro and in vivo. Hemodynamic changes are pronounced and are related to the speed and size of the propeller.
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