Assessment of distribution and evolution of Mechanical dyssynchrony in a porcine model of myocardial infarction by cardiovascular magnetic resonance

Journal of Cardiovascular Magnetic Resonance

Research

Khaled Z Abd-Elmoniem¹  Sahar Soleimanifard²  Harsh Agarwal²  Jerry L Prince²  Veronica L Dimaano³  Theodore P Abraham³  Amr Youssef³  Hugh Calkins³  Evert-Jan P Vonken³  Tetsuo Sasano³  M Roselle Abraham³  Miguel Santaularia Tomas⁴  Matthias Stuber⁵ 

[1] Biomedical and Metabolic Imaging Branch, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD, USA;Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD, USA;Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, MD, USA;Department of Medicine, Division of Cardiology, Johns Hopkins University, Baltimore, MD, USA;Department of Medicine, Division of Cardiology, Hospital Español de Mexico, Distrito Federal, Mexico;Department of Radiology, Division of Magnetic Resonance Research, Johns Hopkins University, Baltimore, MD, USA;

关键词: Cardiovascular Magnetic Resonance;    Cardiac Resynchronization Therapy;    Late Gadolinium Enhancement;    Post Myocardial Infarction;    Mechanical Dyssynchrony;   

DOI  :  10.1186/1532-429X-14-1

 received in 2011-08-23, accepted in 2012-01-06,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundWe sought to investigate the relationship between infarct and dyssynchrony post- myocardial infarct (MI), in a porcine model. Mechanical dyssynchrony post-MI is associated with left ventricular (LV) remodeling and increased mortality.MethodsCine, gadolinium-contrast, and tagged cardiovascular magnetic resonance (CMR) were performed pre-MI, 9 ± 2 days (early post-MI), and 33 ± 10 days (late post-MI) post-MI in 6 pigs to characterize cardiac morphology, location and extent of MI, and regional mechanics. LV mechanics were assessed by circumferential strain (eC). Electro-anatomic mapping (EAM) was performed within 24 hrs of CMR and prior to sacrifice.ResultsMean infarct size was 21 ± 4% of LV volume with evidence of post-MI remodeling. Global eC significantly decreased post MI (-27 ± 1.6% vs. -18 ± 2.5% (early) and -17 ± 2.7% (late), p < 0.0001) with no significant change in peri-MI and MI segments between early and late time-points. Time to peak strain (TTP) was significantly longer in MI, compared to normal and peri-MI segments, both early (440 ± 40 ms vs. 329 ± 40 ms and 332 ± 36 ms, respectively; p = 0.0002) and late post-MI (442 ± 63 ms vs. 321 ± 40 ms and 355 ± 61 ms, respectively; p = 0.012). The standard deviation of TTP in 16 segments (SD16) significantly increased post-MI: 28 ± 7 ms to 50 ± 10 ms (early, p = 0.012) to 54 ± 19 ms (late, p = 0.004), with no change between early and late post-MI time-points (p = 0.56). TTP was not related to reduction of segmental contractility. EAM revealed late electrical activation and greatly diminished conduction velocity in the infarct (5.7 ± 2.4 cm/s), when compared to peri-infarct (18.7 ± 10.3 cm/s) and remote myocardium (39 ± 20.5 cm/s).ConclusionsMechanical dyssynchrony occurs early after MI and is the result of delayed electrical and mechanical activation in the infarct.

【 授权许可】

Unknown   
© Abd-Elmoniem et al; licensee BioMed Central Ltd. 2012. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.