A method and apparatus for verifying a determined cardiac event in a medical device based on detected variation in hemodynamic status that includes a physiologic sensor sensing physiologic signals to generate a plurality of variation index samples corresponding to the sensed signals, and a microprocessor computing a variation index trend associated with a predetermined number of variation index samples of the plurality of variation index samples, determining whether deviations of the predetermined number of variation index samples over predetermined sampling windows are less than a deviation threshold, and determining, in response to the deviations being less than the deviation threshold, a corrected variation index trend in response to the changes in the variation index trend during the predetermined sampling windows.