Estimation of the changes of the beat-to-beat 3D orientation of the heart from the orthogonal ECG

Starting from the hypothesis that the QRS and T loops of the orthogonal ECG are almost planar and tied to the heart anatomy, the authors have developed a method based on the measurement of the changes of the three-dimensional orientation of the spatio-temporal loops to estimate the changes of the beat-to-beat orientation of any anatomic axis of the heart. The methodology the authors developed is based on the CAVIAR approach. This guarantees a precise measurement of the changes of the orientation of the QRS and T loops inertia axes by overcoming any spatio-temporal changes ascribable to desynchronizations or physiology. The anatomic orientations of the left ventricle long axis (LVLA) were determined by MRI for different body positions and compared to the estimated values. Preliminary results indicate that the authors´ method is suitable for the estimation of the changes of the beat-to-beat spatial orientation of the LVLA