Patent ID: 7283873

Claim:
In an implantable cardiac stimulation device, a method comprising: collecting a plurality of right ventricle (RV) contraction parameters during at least one cardiac cycle; collecting a plurality of left ventricle (LV) contraction parameters during said at least one cardiac cycle, without using a LV pressure sensor, wherein said plurality of LV contraction parameters includes a plurality of LV impedance values and collecting said plurality of LV contraction parameters includes measuring said plurality of LV impedance values using a first electrode having at least one electrical contact within the right ventricle, and a second electrode associated with said left ventricle, said second electrode having at least one electrical contact with cardiac tissue of said left ventricle, said first and second electrodes operatively arranged to pass an electrical signal on a path that includes blood within a chamber of the left ventricle; and processing said RV contraction parameters as a function of said LV contraction parameters to produce data corresponding to an RV-LV contraction loop.