Myocardial work index better reflects contractility than longitudinal strain in rat models of pressure- and volume overload-induced heart failure

Abstract Funding Acknowledgements Type of funding sources: None. Speckle-tracking echocardiography (STE)-derived global longitudinal strain (GLS) is considered to be a sensitive marker left ventricular (LV) function in wide variety cardiovascular diseases. Still, evidence suggests that GLS significantly influenced by loading conditions. Myocardial work index (MWI) evaluates myocardial deformation the context afterload through interpretation relation instantaneous LV pressure. MWI may potentially overcome limitations mere calculation, and better reflect cardiac contractility hemodynamic overload states. Accordingly, our aim was examine relationship with load-independent markers rat models pressure- volume overload-induced heart failure. Male Wistar rats underwent transverse aortic constriction (TAC; n = 12) generate pressure overload, or aortocaval fistula (ACF; established induce severe overload. In case control groups, sham procedures were performed (n 12/12). Echocardiography loops obtained determine STE-derived MWI. Pressure-volume analysis transient occlusion inferior vena cava carried out calculate preload recruitable stroke (PRSW), as „gold-standard" parameter contractility. mildly reduced ACF group (-13.2 ± 2.4 vs. -15.4 2.0%, p < 0.05), while it lower TAC compared controls (-7.0 2.8 -14.5 2.5%; 0.001). contrast these findings, PRSW also (58 14 111 40 mmHg; 1328 411 1934 308 mmHg%, both 0.01), however, they comparable between corresponding (110 26 116 68 1687 275 Hgmm% 1537 662 Hgmm%; NS). pooled population, did not show (r=-0.23; 0.12), showed significant correlation (r 0.70; conditions, therefore, reliable model induced failure, maintained despite decreased GLS, reflects states, more suitable systolic function. Figure. Pressure-strain groups