Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
New ultrasonographic approaches to monitoring cardiac and vascular function
KTH, School of Technology and Health (STH), Medical Engineering. (Medicinsk teknik)
2009 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Atherosclerotic cardiovascular disease is the leading cause of death worldwide. To decrease mortality and morbidity in cardiovascular disease, the development of accurate, non-invasive methods for early diagnosis of atherosclerotic cardiac and vascular engagement is of considerable clinical interest. Cardiovascular ultrasound imaging is today the cornerstone in the routine evaluation of cardiovascular function and recent development has resulted in two new techniques, tissue velocity imaging (TVI) and speckle tracking, which allow objective quantification of cardiovascular function. TVI and speckle tracking are the basis for three new approaches to cardiac and vascular monitoring presented in this thesis: wave intensity wall analysis (WIWA), two-dimensional strain imaging in the common carotid artery, and the state diagram of the heart.

 

WIWA uses longitudinal and radial strain rate as input for calculations of wave intensity in the arterial wall. In this thesis, WIWA was validated against a commercially available wave intensity system, showing that speckle tracking-derived strain variables can be useful in wave intensity analysis. WIWA was further tested in patients with end stage renal disease and documented high mortality in cardiovascular disease. The latter study evaluated the effects of a single session of hemodialysis using WIWA and TVI variables and showed improved systolic function after hemodialysis. The results also indicated that preload-adjusted early systolic wave intensity obtained by the WIWA system may contribute in the assessment of left ventricular contractility in this patient category. Two-dimensional strain imaging in the common carotid artery is a new approach showing great potential to detect age-dependent differences in mechanical properties of the common carotid artery. Among the measured strain variables, global circumferential strain had the best discriminating performance and appeared to be superior to conventional measures of arterial stiffness such as elastic modulus and β stiffness index. The state diagram is a visualisation tool that provides a quantitative overview of the temporal interrelationship of mechanical events in the left and right ventricles. Case examples and a small clinical study showed that state diagrams clearly visualize cardiac function and can be useful in the detection of non ST-elevation myocardial infarction (NSTEMI).

 

Even though WIWA, two-dimensional strain imaging in the common carotid artery and the state diagram show potential to be useful in the evaluation of cardiovascular function, there still remains a considerable amount of work to be done before they can be used in the daily clinical practice.

Place, publisher, year, edition, pages
Stockholm: KTH , 2009. , xiv, 47 p.
Series
Trita-STH : report, ISSN 1653-3836 ; 2009:7
National Category
Biomedical Laboratory Science/Technology
Identifiers
URN: urn:nbn:se:kth:diva-11760ISBN: 978-91-7415-525-9 (print)OAI: oai:DiVA.org:kth-11760DiVA: diva2:280837
Public defence
2010-01-22, 3-221, Alfred nobels alle 10, Huddinge, 13:00 (Swedish)
Opponent
Supervisors
Note
QC 20100705Available from: 2009-12-14 Created: 2009-12-11 Last updated: 2010-07-05Bibliographically approved
List of papers
1. Wave intensity wall analysis: a novel noninvasive method to measure wave inntensity
Open this publication in new window or tab >>Wave intensity wall analysis: a novel noninvasive method to measure wave inntensity
Show others...
2009 (English)In: Heart and Vessels, ISSN 0910-8327, E-ISSN 1615-2573, Vol. 24, 357-365 p.Article in journal (Refereed) Published
Abstract [en]

Wave intensity analysis is a concept providing information about the interaction of the heart and the vascular system. Originally, the technique was invasive. Since then new noninvasive methods have been developed. A recently developed ultrasound technique to estimate tissue motion and deformation is speckle-tracking echocardiography. Speckle tracking-based techniques allow for accurate measurement of movement and deformation variables in the arterial wall in both the radial and the longitudinal direction. The aim of this study was to test if speckle tracking-derived deformation data could be used as input for wave intensity calculations. The new concept was to approximate changes of flow and pressure by deformation changes of the arterial wall in longitudinal and radial directions. Flow changes (dU/dt) were approximated by strain rate (sr, 1/s) of the arterial wall in the longitudinal direction, whereas pressure changes (dP/dt) were approximated by sign reversed strain rate (1/s) in the arterial wall in the radial direction. To validate the new concept, a comparison between the newly developed Wave Intensity Wall Analysis (WIWA) algorithm and a commonly used and validated wave intensity system (SSD-5500, Aloka, Tokyo, Japan) was performed. The studied population consisted of ten healthy individuals (three women, seven men) and ten patients (all men) with coronary artery disease. The present validation study indicates that the mechanical properties of the arterial wall, as measured by a speckle tracking-based technique are a possible input for wave intensity calculations. The study demonstrates good visual agreement between the two systems and the time interval between the two positive peaks (W1-W2) measured by the Aloka system and the WIWA system correlated for the total group (r = 0.595, P < 0.001). The correlation for the diseased subgroup was r = 0.797, P < 0.001 and for the healthy subgroup no significant correlation was found (P > 0.05). The results of the study indicate that the mechanical properties of the arterial wall could be used as input for wave intensity calculations. The WIWA concept is a promising new method that potentially provides several advantages over earlier wave intensity methods, but it still has limitations and needs further refinement and larger studies to find the optimal clinical use.

Keyword
Wave intensity; Ultrasound; Speckle tracking; Arterial stiffness
National Category
Production Engineering, Human Work Science and Ergonomics
Identifiers
urn:nbn:se:kth:diva-11743 (URN)10.1007/s00380-008-1112-3 (DOI)000270225400007 ()19784819 (PubMedID)2-s2.0-70349641505 (Scopus ID)
Note

QC 20100624

Available from: 2009-12-14 Created: 2009-12-11 Last updated: 2017-12-12Bibliographically approved
2. Effects of hemodialysis on the cardiovascular system: Quantitative analysis using wave intensity wall analysis and tissue velocity imaging
Open this publication in new window or tab >>Effects of hemodialysis on the cardiovascular system: Quantitative analysis using wave intensity wall analysis and tissue velocity imaging
Show others...
2010 (English)In: Heart and Vessels, ISSN 0910-8327, E-ISSN 1615-2573Article in journal (Refereed) Published
Abstract [en]

Cardiovascular disease is the leading cause of death in patients with end stage renal disease (ESRD). The aim of this study was to investigate the changes in cardiovascular function induced by a single session of hemodialysis (HD) by the analysis of cardiovascular dynamics using wave intensity wall analysis (WIWA) and of systolic and diastolic myocardial function using tissue velocity imaging (TVI). Grey-scale cine loops of the left common carotid artery, conventional echocardiography and TVI images of the left ventricle were acquired before and after HD in 45 patients (17 women, mean age 54) with ESRD. The WIWA indexes, W1 preload-adjusted W1, W2 and preload-adjusted W2, and the TVI variables, isovolumic contraction velocity (IVCV), isovolumic contraction time (IVCT), peak systolic velocity (PSV), displacement, isovolumic relaxation velocity (IVRV), isovolumic relaxation time (IVRT), peak early diastolic velocity (E’) and peak late diastolic velocity (A’), were compared before and after HD. The WIWA measurements showed significant increases in W1 (p < 0.05) and preload-adjusted W1 (p < 0.01) after HD. W2 was significantly decreased (p < 0.05) after HD, whereas the change in preload-adjusted W2 was not significant. Systolic velocities, IVCV (p < 0.001) and PSV (p < 0.01), were increased after HD, whereas the AV-plane displacement were decreased (p < 0.01). For the measured diastolic variables, E’ was significantly decreased (p < 0.01) and IVRT was significantly prolonged (p < 0.05), after HD. A few correlations were found between WIWA and TVI variables. The WIWA and TVI measurements indicate that a single session of HD improves systolic function. The load dependency of the diastolic variables seems to be more pronounced than for the systolic variables. Preload-adjusted wave intensity indexes may contribute in the assessment of true LV contractility and relaxation.

National Category
Medical Laboratory and Measurements Technologies
Identifiers
urn:nbn:se:kth:diva-11755 (URN)10.1007/s00380-010-0050-z (DOI)000290540600008 ()21063879 (PubMedID)2-s2.0-79959734650 (Scopus ID)
Note
Uppdaterad från Manuskript till Artikel (2011208) QC 20100705Available from: 2009-12-11 Created: 2009-12-11 Last updated: 2017-12-12Bibliographically approved
3. Ultrasonographic strain imaging is superior to conventional non-invasive measures of vascular stiffness in the detection of age-dependent differences in the mechanical properties of the common carotid artery
Open this publication in new window or tab >>Ultrasonographic strain imaging is superior to conventional non-invasive measures of vascular stiffness in the detection of age-dependent differences in the mechanical properties of the common carotid artery
Show others...
2010 (English)In: European Journal of Echocardiography, ISSN 1525-2167, E-ISSN 1532-2114, Vol. 11, no 7, 630-636 p.Article in journal (Refereed) Published
Abstract [en]

Aims: Elastic properties of large arteries have been shown to deteriorate with age and in the presence of atherosclerotic vascular disease. In this study, the performance of ultrasonographic strain measurements was compared to conventional measures of vascular stiffness in the detection of age-dependent differences in the elastic properties of the common carotid artery.

Methods and results: In 10 younger (25-28 years, 4 women) and 10 older (50-59 years, 4 women) healthy individuals, global and regional circumferential and radial strain variables were measured in the short-axis view of the right common carotid artery using ultrasonographic two-dimensional (2D) strain imaging with recently introduced speckle tracking technique. Conventional elasticity variables, elastic modulus (Ep) and β stiffness index, were calculated using M-mode sonography and non-invasive blood pressure measurements. Global and regional circumferential systolic strain and strain rate values were significantly higher (p < 0.001, p < 0.01 for regional late systolic strain rate) in the younger individuals, whereas the values of conventional elasticity variables in the same group were lower (p < 0.05). Among all strain and conventional elasticity variables, principal component analysis and its regression extension identified only circumferential systolic strain variables as contributing significantly to the observed discrimination between the younger and older age groups.

Conclusion: Ultrasonographic 2D-strain imaging is a sensitive method for the assessment of elastic properties in the common carotid artery, being in this respect superior to conventional measures of vascular elasticity. The method has potential to become a valuable non-invasive tool in the detection of early atherosclerotic vascular changes.

National Category
Medical Laboratory and Measurements Technologies
Identifiers
urn:nbn:se:kth:diva-11757 (URN)10.1093/ejechocard/jeq033 (DOI)000280704100016 ()2-s2.0-77955443516 (Scopus ID)
Note

QC 20101208

Available from: 2009-12-11 Created: 2009-12-11 Last updated: 2017-12-12Bibliographically approved
4.
The record could not be found. The reason may be that the record is no longer available or you may have typed in a wrong id in the address field.

Open Access in DiVA

fulltext(3683 kB)1651 downloads
File information
File name FULLTEXT01.pdfFile size 3683 kBChecksum SHA-512
726a4aee9035350bd16fe32fa3766d09a3d337096d13cfac32b9a49da488fe1f7f6ddf064abfb7a27175691ba6ab15ade62f73490fa68915889689d41e6ab0a5
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Bjällmark, Anna
By organisation
Medical Engineering
Biomedical Laboratory Science/Technology

Search outside of DiVA

GoogleGoogle Scholar
Total: 1651 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 403 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf