liu.seSök publikationer i DiVA
Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Spatial and Temporal Inhomogeneity of Left Ventricular Myocardial Transmural Strains During Diastole
Linköpings universitet, Institutionen för medicinsk teknik, Biomedicinsk modellering och simulering. Linköpings universitet, Tekniska högskolan.
Visa övriga samt affilieringar
(Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
Abstract [en]

Rapid early filling requires a rapid shift to a very compliant left ventricle immediately after systole, allowing filling at low driving pressures. This compliance shift is manifested as changes in transmural strains: however its mechanistic basis is incompletely understood. Seven adult Dorsett hybrid sheep were anesthetized and radiopaque markers were surgically implanted to silhouette the LV chamber. Three transmural columns of four beads each were implanted into the lateral equatorial LV wall. Eight weeks after surgery, biplane videofluoroscopic images of all radiopaque markers were acquired at 60 Hz horn dosed-chest anesthetized animals. After data acquisition, hearts were arrested at the end-diastolic pressure aud quantitative hist.ology was used to determine fiber and sheet angles. Lagrangian strains in cardiac and liber-sheet coordinates were computed at end of early filling and end diastole with filling onset as reference at three transmural depths. Rapid early filling was dominated by subepicardial circumferential stretching (ECC=0.08±0.02) and fiber lengthening (Eƒƒ=0.03±0.01), midwall circumferential stretching (ECC=0.07±0.02), and subendocardial wall thinning (ERR=-0.05±0.01). Subepicardial strains achieved their ED values during early diastole, while mid wall and subendocardial straius reset during late diastole. Sheet-normal shear strain was a dominant contributor to wall thinning during diastole.

Nyckelord [en]
cardiac strains, fiber-sheet strains, sheep, LV filling
Nationell ämneskategori
Teknik och teknologier
Identifikatorer
URN: urn:nbn:se:liu:diva-100800OAI: oai:DiVA.org:liu-100800DiVA, id: diva2:663733
Tillgänglig från: 2013-11-12 Skapad: 2013-11-12 Senast uppdaterad: 2013-11-12
Ingår i avhandling
1. Modelling of strain tensors in cardiac kinematics
Öppna denna publikation i ny flik eller fönster >>Modelling of strain tensors in cardiac kinematics
2006 (Engelska)Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

The heart wall consists of three distinct layers: the inner endocardium, the middle myocardium and the outer epicardium. The myocardium is the functional tissue that endows the heart with its ability to pump blood, and consists primarily of locally parallel muscle fibers. The orientation of these muscle fibers change with position in the wall. The myofibers have been shown to be arranged parallel in sheets that are rotated around the fiber direction relative to the radial direction of the left ventricle. During a cardiac beat there are local shortenings and lengthenings in the myocardium, both within and between myolaminar sheets. The mechanism by which the local shortening or lengthening is translated into the large and complex motions of the ventricle has to be studied on a local level, by studying deformation. A parameter that describes deformation is strain. The scope of the current project is to perform detailed studies of cardiac strain, particularly during diastole. There exist several definitions of strain tensors and the focus in this project is on the Lagrangian strain tensor.

The myocardial bead array gives kinematic measures of the myocardium toestimate strain in the left ventricular wall of the pumping heart. During surgery, radiopaque beads are inserted into the myocardium along three transmural columns, with typically four to six beads in each column. The 4D coordinates of the beads are acquired with high resolution using time-resolved biplane cineradiography.

This thesis presents a method for strain estimation from myocardial coordinate data. This strain estimation method is tailored for the transmural bead array and fits a polynomial to the bead coordinates. A benefit with the polynomial method is its ability to avoid loss of accuracy for the case of a missing bead, e.g. due to problems sometimes encountered during surgery or during the recovery period. The polynomial strain estimation method is applied to coordinate data from a transmural bead array to quantify diastolic myocardial strain in the ovine heart. This reveals transmural strain inhomogeneities during diastole in the ovine heart.

Ort, förlag, år, upplaga, sidor
Linköping: Linköpings universitet, 2006. s. 36
Serie
Linköping Studies in Science and Technology. Thesis, ISSN 0280-7971 ; 1269
Serie
LIU-TEK-LIC ; 50
Nationell ämneskategori
Medicin och hälsovetenskap
Identifikatorer
urn:nbn:se:liu:diva-35139 (URN)25032 (Lokalt ID)91-85643-89-0 (ISBN)25032 (Arkivnummer)25032 (OAI)
Tillgänglig från: 2009-10-10 Skapad: 2009-10-10 Senast uppdaterad: 2023-02-15

Open Access i DiVA

Fulltext saknas i DiVA

Person

Kindberg, Katarina

Sök vidare i DiVA

Av författaren/redaktören
Kindberg, Katarina
Av organisationen
Biomedicinsk modellering och simuleringTekniska högskolan
Teknik och teknologier

Sök vidare utanför DiVA

GoogleGoogle Scholar

urn-nbn

Altmetricpoäng

urn-nbn
Totalt: 134 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf