Is post-systolic shortening a reliable indicator of myocardial viability? An MR tagging and late-enhancement study.

Détails

ID Serval
serval:BIB_CD3A74539975
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Is post-systolic shortening a reliable indicator of myocardial viability? An MR tagging and late-enhancement study.
Périodique
Journal of Cardiovascular Magnetic Resonance
Auteur(s)
Ryf S., Rutz A.K., Boesiger P., Schwitter J.
ISSN
1097-6647 (Print)
ISSN-L
1097-6647
Statut éditorial
Publié
Date de publication
2006
Volume
8
Numéro
3
Pages
445-451
Langue
anglais
Notes
Publication types: Journal Article
Publication Status: ppublish
Résumé
PURPOSE: In ischemic myocardium systolic strain is reduced and followed by a deformation after systole, the so-called post-systolic shortening. The presence of post systolic shortening is therefore considered a marker of viability even though its mechanism remains unclear. The hypothesis was tested whether post-systolic shortening might be a passive recoil phenomenon and therefore not uniquely associated with viability.
METHODS: Five patients with a history of myocardial infarctions and fully transmural scars in late enhancement imaging and five age-matched healthy volunteers underwent a tagging study to analyze systolic and post-systolic deformation in transmurally infarcted and contra-lateral non-infarcted myocardium. From CSPAMM myocardial tagging data, mid-wall circumferential fiber shortening, radial displacement, and rotation parameters were semi-automatically extracted by harmonic phase (HARP).
RESULTS: In transmurally infarcted myocardium, a post systolic shortening of 6.2 +/- 1.8% was present occurring in early diastole (time to maximum circumferential fiber shortening increased versus both, contralateral myocardium and corresponding sectors in healthy volunteers, p < 0.01). Maximum radial displacement was decreased in scar tissue (p < 0.001 versus contra-lateral), but time to maximum radial displacement did not differ. Rotation did not discriminate between infarcted and non-infarcted myocardium.
CONCLUSIONS: The pure finding of post-systolic shortening is not sufficient for the diagnosis of residual myocardial viability. Post-systolic shortening may be explained in part by passive recoil, which releases energy stored in the scar tissue during systolic intra-ventricular unloading. Circumferential fiber shortening appears best suited for characterization of regional deformation, whereas radial displacement and rotation are more dependent on tethering effects, and thus, are more likely to reflect global chamber mechanics.
Mots-clé
Analysis of Variance, Case-Control Studies, Contrast Media, Gadolinium DTPA/diagnostic use, Humans, Magnetic Resonance Imaging/methods, Male, Middle Aged, Myocardial Contraction/physiology, Myocardial Infarction/physiopathology, Systole/physiology
Pubmed
Web of science
Création de la notice
07/09/2011 18:12
Dernière modification de la notice
20/08/2019 16:47
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