Cardiac Mechanics and Helical Structure.
The sequential and continuous contraction of the different muscle segments and, thanks to the global three-dimensional orientation as a non-orientable triple torsion geometric surface, explain the mechanical phenomena that occur during the cardiac cycle, as we will review below. Therefore, the traditional concept of electromechanical apex-base activation18 contradicts what has been shown by experimental studies17,19,20 as well as data from echocardiography strain and strain rate quantify an initial movement of the base before shortening ventricular21,22 MRI analyses also support the evidence of contradirectional base-apex rotations in the different phases of the cardiac cycle23, 24.