liu.seSearch for publications in DiVA
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • 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
Turbulent kinetic energy in the right ventricle: Potential MR marker for risk stratification of adults with repaired Tetralogy of Fallot
Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences.
Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Cardiology in Linköping.
Linköping University, Center for Medical Image Science and Visualization (CMIV). Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Heart and Medicine Center, Department of Clinical Physiology in Linköping.
Linköping University, Center for Medical Image Science and Visualization (CMIV). Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Region Östergötland, Heart and Medicine Center, Department of Clinical Physiology in Linköping. Linköping University, Faculty of Medicine and Health Sciences.
Show others and affiliations
2018 (English)In: Journal of Magnetic Resonance Imaging, ISSN 1053-1807, E-ISSN 1522-2586, Vol. 47, no 4, p. 1043-1053Article in journal (Refereed) Published
Abstract [en]

Purpose: To assess right ventricular (RV) turbulent kinetic energy (TKE) in patients with repaired Tetralogy of Fallot (rToF) and a spectrum of pulmonary regurgitation (PR), as well as to investigate the relationship between these 4D flow markers and RV remodeling.

Materials and Methods: Seventeen patients with rToF and 10 healthy controls were included in the study. Patients were divided into two groups based on PR fraction: one lower PR fraction group (11%) and one higher PR fraction group (>11%). Field strength/sequences: 3D cine phase contrast (4D flow), 2D cine phase contrast (2D flow), and balanced steady-state free precession (bSSFP) at 1.5T. Assessment: The RV volume was segmented in the morphologic short-axis images and TKE parameters were computed inside the segmented RV volume throughout diastole. Statistical tests: One-way analysis of variance with Bonferroni post-hoc test; unpaired t-test; Pearson correlation coefficients; simple and stepwise multiple regression models; intraclass correlation coefficient (ICC).

Results: The higher PR fraction group had more remodeled RVs (140 6 25 vs. 107 6 22 [lower PR fraction, P < 0.01] and 93 6 15 ml/m2[healthy, P < 0.001] for RV end-diastolic volume index [RVEDVI]) and higher TKE values (5.95 6 3.15 vs. 2.23 6 0.81 [lower PR fraction, P < 0.01] and 1.91 6 0.78 mJ [healthy, P < 0.001] for Peak Total RV TKE). Multiple regression analysis between RVEDVI and 4D/2D flow parameters showed that Peak Total RV TKE was the strongest predictor of RVEDVI (R25 0.47, P 5 0.002).

Conclusion: The 4D flow-specific TKE markers showed a slightly stronger association with RV remodeling than conventional 2D flow PR parameters. These results suggest novel hemodynamic aspects of PR in the development of late complications after ToF repair.

Place, publisher, year, edition, pages
Hoboken: John Wiley & Sons, 2018. Vol. 47, no 4, p. 1043-1053
Keywords [en]
4D flow, MRI, Turbulence, Tetralogy of Fallot, Turbulent kinetic energy
National Category
Radiology, Nuclear Medicine and Medical Imaging Cardiac and Cardiovascular Systems Medical Laboratory and Measurements Technologies Anesthesiology and Intensive Care Medical Image Processing
Identifiers
URN: urn:nbn:se:liu:diva-143780DOI: 10.1002/jmri.25830ISI: 000427125300016PubMedID: 28766919Scopus ID: 2-s2.0-85026745981OAI: oai:DiVA.org:liu-143780DiVA, id: diva2:1167286
Note

Funding agencies:  European Research Council [310612]; Swedish Heart and Lung Foundation [20140398]; County Council of Ostergotland; Medical Research Council of Southeast Sweden (FORSS); Swedish Research Council [2013-6077, 2014-6191]

Available from: 2017-12-18 Created: 2017-12-18 Last updated: 2019-01-07Bibliographically approved
In thesis
1. The right ventricle in volume or pressure overload: Insights from novel imaging techniques
Open this publication in new window or tab >>The right ventricle in volume or pressure overload: Insights from novel imaging techniques
2019 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This study is inspired by the gap in knowledge regarding the timing of cardiac surgery and interventions in adult patients with congenital heart disease. There are many parameters used assessing right ventricular function; however, most of them have pitfalls. Understanding the pathomechanisms by which the heart adapts to congenital defects is probably key to find the answer when it is time to intervene and start discussing treatment options. Heart defects are the most frequently occurring congenital disorders. Less than 50% of individuals with moderate to severe congenital heart defects, e.g. transposition of the great arteries (TGA) or tetralogy of Fallot (TOF), survive to adulthood without intervention. Advances in cardiac surgery and better identification of individuals at risk for sudden cardiac death have increased survival rates. Currently, more than 96% of patients with congenital heart disease survive to at least 16 years of age; most undergo corrective surgery but are not cured, and only a few have normal physiology and anatomy. In many cases, the heart must develop mechanisms of adaptation to the changed conditions after surgery. Consequently, correction of the defect creates residual disease with a risk of future complications.

To prevent clinical deterioration and to identify the development of complications, patients need lifelong, regular follow up. The choice of followup modalities depends on the cardiac malformation.

The right ventricle (RV) plays an important role, as it is often part of the defect or is influenced by the surgery. In the past, research was focused on assessment of left ventricular function (LV), and the RV was “the forgotten ventricle.” Observations and studies in the last few decades brought increased interest into the RV and revealed the importance of the RV in the prognosis of various cardiac diseases.

An understanding of RV morphology, pathophysiology and adaptive mechanisms is crucial for further studies of prognosis as well as for research linked to the use of particular diagnostic modalities.

When the RV is exposed to increased pressure load, e.g. in atrially corrected transposition of the great arteries (TGA), adaptation affects the cavity volume as well as the wall thickness. When the RV is volume overloaded, adaptation involves enhancement of the RV cavity volume while the wall thickness often remains unchanged under long time. RV ejection fraction (RVEF) gives some information about changes in RV function, but information on myocardial contractility and contractile reserve is also needed. New functional parameters such as strain—also known as myocardial deformation—provide some information about intrinsic myocardial function.

In Paper I, we studied functional parameters such as ejection fraction and strain (radial and longitudinal strain for both ventricles) in patients with Tetralogy of Fallot (TOF) and TGA. Longitudinal RV strain was depressed in both patient groups in comparison with that in healthy individuals, and there were additional differences between the two patient groups.

In Paper II, we validated three-dimensional echocardiography (3DEcho) against the cardiac magnetic resonance (CMR) gold standard. The study population was limited to patients with TOF. In general, 3DEcho underestimated RV volumes but was able to identify patients with RV dilatation on CMR with high sensitivity. RV longitudinal free wall strain measured by CMR with a cut-off set at -14% identified patients with depressed exercise capacity and low peak oxygen uptake.

In Paper III, we studied a new CMR method to quantify and visualise turbulent flow in the heart and vessels. Turbulent flow can be harmful to tissue, blood cells, and endothelium and can contribute to tissue remodeling. In patients with TOF, turbulent flow can be seen as variance in 2DEcho color Doppler. In CMR, increased turbulent kinetic energy (TKE) could be seen with four-dimensional flow. The RV TKE was increased in patients with TOF with pulmonary regurgitation compared with that in healthy controls.

In Paper IV, we validated “knowledge-based reconstruction” (KBR), a novel method to calculate RV volume, against CMR in patients with various types of congenital heart defects. Two-dimensional echocardiogram-based threedimensional RV reconstruction is a relatively uncomplicated method that creates a three-dimensional RV model based on a limited number of predefined points of interest (RV structures such as tricuspid annulus, RV free wall, or pulmonary valve).

KBR showed good agreement with CMR (intraclass correlation coefficient = 0.84 for RV end-diastolic volume and 0.89 for ejection fraction) but tended to underestimate RV volumes, which is in line with other methods based on ultrasound.

Conclusions: 3DEcho is an evolving modality that is able to identify patients with RV dilatation. It can be used clinically for the follow up of patients with congenital heart diseases, especially those with mildly to moderately dilated RVs. When an intervention seems likely, 3DEcho results should be verified by CMR. CMR-derived measurements of longitudinal and radial strain provide a new understanding of RV remodeling and ventricular interdependence in patients with TOF and TGA. Depressed longitudinal strain may indicate a risk of depressed exercise capacity and, in patients with TGA, clinical deterioration.

Further studies in larger populations of patients with congenital heart defects are needed, as the altered RV morphology in such patients makes quantitative assessment especially challenging.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2019. p. 82
Series
Linköping University Medical Dissertations, ISSN 0345-0082 ; 1653
National Category
Cardiac and Cardiovascular Systems
Identifiers
urn:nbn:se:liu:diva-153732 (URN)10.3384/diss.diva-153732 (DOI)9789176851678 (ISBN)
Public defence
2019-02-15, Hugo Theorell-salen, Campus US, Linköping, 13:00 (English)
Opponent
Supervisors
Available from: 2019-01-07 Created: 2019-01-07 Last updated: 2019-01-07Bibliographically approved

Open Access in DiVA

fulltext(379 kB)26 downloads
File information
File name FULLTEXT01.pdfFile size 379 kBChecksum SHA-512
43ded10dffb459c69f4d0164a16b1ba1d9eb27fd3c8885858d906d8655af3f2f80b7e6d51852f3168523ccd5bd828ab9d42f91868bb74d1ccc88930ac5994e4f
Type fulltextMimetype application/pdf

Other links

Publisher's full textPubMedScopus

Authority records BETA

Fredriksson, Alexandru GrigorescuTrzebiatowska-Krzynska, AleksandraDyverfeldt, PetterEngvall, JanEbbers, TinoCarlhäll, Carljohan

Search in DiVA

By author/editor
Fredriksson, Alexandru GrigorescuTrzebiatowska-Krzynska, AleksandraDyverfeldt, PetterEngvall, JanEbbers, TinoCarlhäll, Carljohan
By organisation
Division of Cardiovascular MedicineFaculty of Medicine and Health SciencesDepartment of Cardiology in LinköpingCenter for Medical Image Science and Visualization (CMIV)Department of Clinical Physiology in Linköping
In the same journal
Journal of Magnetic Resonance Imaging
Radiology, Nuclear Medicine and Medical ImagingCardiac and Cardiovascular SystemsMedical Laboratory and Measurements TechnologiesAnesthesiology and Intensive CareMedical Image Processing

Search outside of DiVA

GoogleGoogle Scholar
Total: 26 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

doi
pubmed
urn-nbn

Altmetric score

doi
pubmed
urn-nbn
Total: 94 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • 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