The actual level of radioactivity is directly and linearly proportional to the volumes of blood within the heart chambers. The blue curve reflects the variation of the first differential of the volume time curve. The histogram is a frequency plot of the RR intervals. The ideal situation is where the plot is a vertical line. In this case only four beats fell outside a predetermined acceptable range of RR intervals.
More sophisticated software allows for 'binning' of data after the study is completed.
This volume time curve from another patient demonstrates peak and average ventricular ejection and filling rates. The effect of Adriamycin cardio-toxicity is reflected in the inability of the heart to contract rapidly and forcefully. Computer derived areas of interest for determining the edges of the left and right ventricles. An area of the ventricle that begins to contract later than another area will demonstrate a phase shift. The images are color coded to demonstrate the relative amplitudes and phase shifts.