Method and apparatus for monitoring a plurality of physiological factors contributing to physiological conditions of a heart, that determines a first impedance, corresponding to the plurality of physiological factors, across a plurality of vectors, and a second impedance, corresponding to the plurality of physiological factors, across the plurality of vectors subsequent to determining the first impedance. A relative change in impedance corresponding to the plurality of vectors is determined in response to the first impedance and the second impedance, first minimally contributing physiological factors of the plurality of physiological factors associated with a first physiological factor of the plurality of physiological factors are determined, and relative change in tissue resistivity corresponding to the first physiological factor in response to physiological factors of the plurality of physiological factors other than the first minimal contributing physiological factors and the relative change in impedance are determined.