ECHONOMY Tools for Echocardiographic Calculations Muhamed Saric, MD, PhD New York University

Rotation (degrees or radians) should refer to the rotation of short-axis sections of the left ventricle as viewed from the apical end and deﬁned as the angle (in degrees or radians) between radial lines connecting the center of mass of that speciﬁc cross-sectional plane to a speciﬁc point in the myocardial wall at end-diastole and at any other time during systole.

Twist (degrees or radians) is the absolute apex-to-base difference in LV rotation (also in degrees or radians) is stated as the net LV twist angle or the net LV torsion angle.

Torsion (degrees/cm or radians/m) should be used for deﬁning the base-to-apex gradient in the rotation angle along the longitudinal axis of the left ventricle, expressed in degrees per centimeter or radians per meter.