the ratio of impedance just before t-wave to that just after r-wave ( [ zt ] / [ zr ] ) of an in situ heart was increased when the ventricle contracted isovolumetrically by means of mineral oil : the ratio was far less than 1.0 in control ventricle , while it was more than 1.0 in oil-filled one ( 2/3 cases ) .
C0018787
heart
C0018827
ventricle