Background

Echocardiography-derived rotational parameters of the left ventricle (LV), “twist” and “torsion”, provide information about the mechanical myocardial function. Conceptionally, these markers relate to action potential duration and mirror the mechano-energetic gradients across endo- and epicardial cells. 3D echo holds promise to overcome the methodological limitations of 2D speckle tracking echo and to validly measure LV rotational parameters. We investigated the determinants of 3D echocardiography-derived LV rotational parameters in a large population-based cohort.

Methods and Results

The prospective Characteristics and Course of Heart Failure Stages A-B and Determinants of Progression (STAAB) cohort study examines a representative sample of inhabitants of the City of Würzburg, aged 30- 79 years, without history of heart failure, stratified for age and sex.

Within the 4-year follow-up examination, 3D echocardiography images were recorded in n=2798 subjects (Vivid E95, GE, Horten, Norway). Valid image analysis including LV twist and torsion measurements (TomtecArena®, Tomtec Imaging Systems, Unterschleißheim, Germany) could be derived in n=1826 subjects (feasibility 65.3%, mean age 57 years, 49.2% women).

With advancing age we observed a linear increase in both LV twist (+0.046° per year, p<0.001) and LV torsion (+0.01°/cm per year, p<0.001). Both LV twist (+0.25° per %LVEF, p<0.001) and LV torsion (+ 0.03°/cm per %LVEF, p<0.001) increased with higher LVEF values. All these associations were independent of sex.

Further, LV twist increased with higher stroke volume (+0.07° per ml, p<0.001) and tricuspid annular plane systolic excursion (+0.198° per mm, p<0.001) in women, but not in men. Independent of sex, LV torsion was inversely associated with height, (-0.009°/cm per cm, p=0.003), body weight (-0.004 °/cm per kg, p=0.016), LV end-diastolic volume (-0.002°/cm per ml, p=0.048) and LV mass (-0.001 °/cm per g, p=0.027).  

Conclusion

In a well characterized and large population-based sample, we identified factors determining LV rotation. LV twist and LV torsion increased with age, yet decreased with higher body weight as well as with deviation from normal LV morphology. An increase in LV rotation might be a sex-independent decisive factor in maintaining LVEF in the face of progressive remodeling, which is known to negatively impact on longitudinal LV function.