In:
Circulation, Ovid Technologies (Wolters Kluwer Health), Vol. 107, No. 6 ( 2003-02-18), p. 883-888
Abstract:
Background— In a correlative functional/histopathologic study, we investigated the regional deformation characteristics of both chronic nontransmural and transmural infarctions before and after a dobutamine challenge. Methods and Results— After stenosing copper-coated stent implantation to produce circumflex artery endothelial proliferation, 18 pigs were followed up for 5 weeks. Posteuthanasia histology showed 10 to have a nontransmural and 8 a transmural infarction. Eight nonstented animals served as controls. Regional radial function was monitored by measuring ultrasound-derived peak systolic strain rates (SR SYS ) and systolic strains (ε SYS ) (1) before stent implantation and (2) at 5 weeks, at baseline (bs) and during an incremental dobutamine infusion. In controls, dobutamine induced a linear increase in SR SYS (dobutamine: bs, 4.8±0.4 s −1 ; 20 μg · kg −1 · min −1 , 9.9±0.7 s −1 ; P 〈 0.0001) and an initial increase of ε SYS at low dose (bs, 58±5%; at 5 μg · kg −1 · min −1 , 78±6%; P 〈 0.05) but a subsequent decrease during higher infusion rates. In the nontransmural group, bs SR SYS and ε SYS were significantly lower than prestent values (SR SYS , 2.9±0.5 s −1 and ε SYS , 32±6%, P 〈 0.05 versus prestent). During dobutamine infusion, SR SYS increased slightly at 5 μg · kg −1 · min −1 (4.7±0.6 s −1 , P 〈 0.05) but fell during higher infusion rates, whereas ε SYS showed no change. For nontransmural infarctions, transmural scar extension correlated closely with ε SYS at bs ( r =0.88). For transmural infarctions, SR SYS at bs was significantly reduced and ε SYS was almost not measurable (SR SYS , 1.8±0.3 s −1 ; ε SYS , 3±4%). Both deformation parameters showed no further change during the incremental dobutamine infusion. Conclusions— Ultrasonic deformation values could clearly differentiate chronic nontransmural from transmural myocardial infarction. The transmural extension of the scar could be defined by the regional deformation response.
Type of Medium:
Online Resource
ISSN:
0009-7322
,
1524-4539
DOI:
10.1161/01.CIR.0000050146.66577.4B
Language:
English
Publisher:
Ovid Technologies (Wolters Kluwer Health)
Publication Date:
2003
detail.hit.zdb_id:
1466401-X
Permalink