Abstract 421: Left Ventricular Torsional Mechanics Worsen With Left Ventricular Remodeling in Heart Failure
Background: Two-dimensional speckle tracking imaging (STI) enables the measurement of LV torsion, a key element in LV systolic mechanics. We addressed the relationship between LV torsion and LV remodeling in patients with LV systolic dysfunction.
Methods: We examined data from 50 consecutive patients with LV systolic dysfunction who underwent dyssynchrony studies. From those, LV torsion could be analyzed in 28 patients. LV torsion was defined as the net-difference of LV rotation (LVrot) between apical and basal short-axis planes obtained from STI analysis. Other variables measured were: LV mass by area-length method, LV sphericity as the ratio of the end-diastolic minor axis to the major axis length of the LV, and LV volumes and ejection fraction (EF) by Simpson’s method.
Results: Most patients were male (71%), had coronary artery disease (54%), and presented with class III or IV symptoms (64%). All patients had LV EF under 50%. Basal LVrot, apical LVrot and LV torsion were −3.7±3.2°, 2.4±4.0°, and 6.1±3.9°, respectively. Basal LVrot was clockwise in 24 patients and apical LVrot was counterclockwise in 21 patients. LV torsion correlated (p<0.01) negatively to LV end-diastolic (r = −0.56) and end-systolic (r = −0.56) volumes, LV sphericity index (r = −0.52), and LV mass (r = −0.52; Figure 1⇓). The correlation between LV torsion and EF was marginal (r = 0.32; p = 0.09). LV torsion correlated negatively to the QRS duration (r = −0.41; p = 0.02).
Conclusions: LV torsion decreases proportionally to LV remodeling as the LV dilates and assumes a more spherical shape. LV torsion may become an important LV performance parameter while providing insights into mechanisms of LV remodeling in heart failure.