[Phase plane (volume to volume-time function loop) display of the data from radionuclide ventriculography obtained by single cardiac probe system].

To assess the left ventricular (LV) performance more sensitively, a new display method of phase plane (PP), displaying volume and volume-time function (dV/dt) in a single image, was applied to radionuclide ventriculography obtained by a single cardiac probe system. In this PP loop, the width of the horizontal axis indicates relative LV volume, and the height of the vertical axis indicates dV/dt. The direction of the rotation of this loop is clockwise. We classified 160 patients with various heart diseases into seven groups, according to the configuration of the loop. And we proposed two new parameters, named peak S and peak D, from this PP display. We can easily detect the left atrial contribution (AC/SV) and its peak rate (peak AC), which are very sensitive parameters for detecting the left ventricular diastolic function abnormality. With these parameters, we can detect 105 patients (74.5%) with abnormal LV function out of 141 patients with various heart diseases. However, with conventional parameters (named EF, PER, PFR, 1/3 EF), we can detect only 80 patients (56.7%) with LV dysfunction. Therefore, we conclude that the single image PP display is a sensitive method for assessing the abnormality of the LV function, not only by evaluating the conventional parameters, but also by analyzing the configuration of the volume to volume-time function loop.