The geometry of the left ventricle in the isovolumic period

Studying the wall movements of the left ventricle in the anterior (p.a.), RAO and in the left lateral projections produces nothing but incorrect results. Only the comparison of movements in the various blood-flow tracts (in LAO-projection) enables us to state that a real increase in the transverse diameter of the cavity takes place during the isovolumic period. This phenomenon occurs in the inflow tract on the side opposite to the interventricular wall (Margo obtusus). Roentgenological study in combination with other techniques for examining the heart movements during the isovolumic period shows that their character and type are mainly determined by the position of the body and the phase of the respiratory cycle. The best conditions for the analysis of changes in the geometry of the left ventricle are with the subject in the vertical position and in the LAO projection during deep inspiration.