Influence of Ventricular Wringing on the Preservation of Left Ventricular Ejection Fraction in Cardiac Amyloidosis

J Am Soc Echocardiogr. 2021 Jul;34(7):767-774. doi: 10.1016/j.echo.2021.02.016. Epub 2021 Mar 18.

Abstract

Background: The purpose of this work was to determine the influence of myocardial wringing on ventricular function in patients with cardiac amyloidosis (CA).

Methods: Fifteen healthy volunteers (group 1) and 34 patients with CA (17 with left ventricular ejection fractions [LVEFs] ≥ 53% [group 2] and 17 with LVEFs < 53% [group 3]) were evaluated using two-dimensional speckle-tracking echocardiography. A control group of mass-matched patients (n = 20) with left ventricular (LV) hypertrophy and LVEFs ≥ 53% was also included. Longitudinal strain (LS), circumferential strain, and LV twist and torsion were calculated. Deformation index (DefI), a new parameter of wringing, calculated as twist/LS, that takes into account actions that occur simultaneously during LV systole (i.e., longitudinal shortening and twist), was evaluated. Torsional and wringing parameters were calculated according to LVEF.

Results: Lower global values of LS and circumferential strain were observed among patients with CA (LS: group 1, -20.6 ± 2.5%; group 2, -11.6 ± 4.1%; group 3, -9.0 ± 3.1%; circumferential strain: group 1, -22.7 ± 4.9%; group 2, -14.4 ± 8.0%; group 3, -13.6 ± 3.8%; P < .001 for both). Torsion did not vary between group 2 and group 1 (2.5 ± 1.1°/cm vs 2.7 ± 0.8°/cm, P = NS). In contrast, DefI was greater in group 2 than in group 1 (-1.8 ± 0.8°/% vs -1.0 ± 0.3°/%, P < .01). Torsion and DefI were lower in group 3 (1.2 ± 0.7°/cm and -1.1 ± 0.6°/%, respectively, P < .001 for both) than in group 2. DefI was similar in patients with LV hypertrophy (-1.7 ± 0.6°/%, P = NS) and group 2.

Conclusions: In patients with CA, preservation of LVEF depends on greater ventricular wringing. DefI, a parameter that integrates the twist and the simultaneous longitudinal shortening of the left ventricle, is a more accurate indicator of the efficacy of this mechanism.

Keywords: Cardiac amyloidosis; Myocardial strain; Myocardial wringing; Ventricular function; Ventricular torsion.

MeSH terms

  • Amyloidosis* / complications
  • Amyloidosis* / diagnosis
  • Echocardiography
  • Heart Ventricles / diagnostic imaging
  • Humans
  • Stroke Volume
  • Ventricular Dysfunction, Left* / diagnostic imaging
  • Ventricular Function, Left