How similar are the mice to men? Between-species comparison of left ventricular mechanics using strain imaging

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 = kMβ. Results: Mean LV mass in individual species varied from 0.038 to 134 g, LV EDV va..