Assessment of cardiac rotation by means of gyroscopic sensors

During the cardiac cycle, contraction of the helically oriented myocardial fibers results in torsion, a wringing motion as the cardiac apex rotates with respect to the base about the Left Ventricle (LV) long axis. We evaluated in animals the use of gyroscopic sensors to quantify cardiac rotation, which was demonstrated to be a sensitive index of cardiac function. Three gyroscopes were epicardially glued at different levels along the LV long axis (apex, middle, base) to assess LV twist dynamics: Angular Velocity (Ang V) and Angle of cardiac rotation (Angle) were measured and evaluated against hemodynamic measurements of LV pressure (LVP, LVdP/dt), at baseline and after acute ischemia induced by coronary ligation. Results demonstrated the feasibility of assessing cardiac rotation and LV twist alterations by means of gyroscopic sensors, especially at apical level: compared with baseline, acute ischemia caused a significant decrease of both Angle and the maximum value of Ang V (mean variation of −37±6% and −21±4%, respectively); a concomitant reduction of LVdP/dt <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">MAX</inf> (−43±4%) was observed.