how similar are the mice to men between-species comparison of left ventricular mechanics using strain imaging是男人的老鼠多么相似物种之间的比较左心室力学使用应变成像.pdfVIP

How Similar Are the Mice to Men? Between-Species Comparison of Left Ventricular Mechanics Using Strain Imaging 1 1 2 2 1 Kenya Kusunose , Marc S. Penn , Youhua Zhang , Yuanna Cheng , James D. Thomas , 1 ´ 1 Thomas H. Marwick , Zoran B. Popovic * 1 Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, Ohio, United States of America, 2 Department of Molecular Cardiology, Cleveland Clinic, Cleveland, Ohio, United States of America Abstract Background: While mammalian heart size maintains constant proportion to whole body size, scaling of left ventricular (LV) function parameters shows a more complex scaling pattern. We used 2-D speckle tracking strain imaging to determine whether LV myocardial strains and strain rates scale to heart size. Methods: We studied 18 mice, 15 rats, 6 rabbits, 12 dogs and 20 human volunteers by 2-D echocardiography. Relationship between longitudinal or circumferential strains/strain rates (SLong/SRLong, SCirc/SRCirc), and LV end-diastolic volume (EDV) or mass were assessed by the allometric (power-law) equation Y = kMb. Results: Mean LV mass in individual species varied from 0.038 to 134 g, LV EDV varied from 0.015 to 102 ml, while RR interval varied from 81 to 1090 ms. While SLong increased with increasing LV EDV or mass (b values 0.047 60.006 and 0.051 60.005, p,0.0001 vs. 0 for both) SCirc was unchanged (p = NS for both LV EDV or mass). Systolic and diastolic SRLong and SRCirc showed inverse correlations to LV EDV or mass (p,0.0001 vs. 0 for all comparisons). The ratio between SLong and SCirc increased with increasing values of LV EDV or mass (b values 0.039 60.010 and 0.040 60.011, p.0.0003 for bot