Document Detail

Vascular tone estimation in patients implanted with the AbioCor implantable replacement heart.
MedLine Citation:
PMID:  15153146     Owner:  NLM     Status:  MEDLINE    
The AbioCor implantable replacement heart provides continuous hydraulic pressure data that are used for control purposes. The magnitude of the end systolic pressure spikes are compared to a preset threshold and used for controlling motor speeds to maintain a full stroke on every beat. Portions of the diastolic pressures of the left and the right side are averaged and can be used for left-right balance control. The mean right diastolic pressure may be used for beat rate (cardiac output) control. The systolic and diastolic hydraulic pressures of the left and right side are correlatable to the respective afterload and preload pressures. More importantly, with known hydraulic pump pressure-flow characteristics, cardiac output is derived. The slopes of the hydraulic pressure traces as a function of time are not used for control or monitoring purposes. However, the magnitudes and shapes of these slopes can provide information on the tones of a patient's vasculature. The ratio of the slope of the systolic pressure to that of the stroke volume yields the vascular tone given in mm Hg/cc. Due to pre-existing pulmonary complications, some AbioCor patients have pulmonary vascular tones that are substantially higher than their respective aortic tones by as much as a factor of four. Pulmonary tones as high as 2 mm Hg/cc, or approximately ten times the normal tone, are recorded. The ratio of averages of the aortic to the pulmonary tone range between 2.2 and 0.25 in patients implanted with the AbioCor compared with a normal value of 5 in subjects without pre-existing pulmonary diseases. The AbioCor implantable replacement heart's hydraulic drive system is capable of providing valuable physiological information, including estimates of physiological pressures, cardiac outputs, and vascular tones.
Robert T V Kung; Hong Zhang
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Publication Detail:
Type:  Comparative Study; Journal Article    
Journal Detail:
Title:  Artificial organs     Volume:  28     ISSN:  0160-564X     ISO Abbreviation:  Artif Organs     Publication Date:  2004 Jun 
Date Detail:
Created Date:  2004-05-21     Completed Date:  2004-08-26     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  7802778     Medline TA:  Artif Organs     Country:  United States    
Other Details:
Languages:  eng     Pagination:  543-8     Citation Subset:  IM    
ABIOMED Inc., 22 Cherry Hill Drive, Danvers, MA 01923, U.S.A.
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MeSH Terms
Aorta / physiology
Blood Pressure
Cardiac Output / physiology*
Equipment Design
Equipment Safety
Follow-Up Studies
Heart, Artificial
Hemodynamics / physiology*
Models, Cardiovascular
Monitoring, Physiologic / methods
Postoperative Period
Pulmonary Artery / physiology
Risk Assessment
Sensitivity and Specificity
Vascular Patency / physiology*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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