A computer system for the analysis of left ventricular pressure and volume

The authors have developed a computer system for the analysis of left-ventricular (LV) pressure-volume (PV) data obtained during catheterization. Global and segmental volumes are measured by conductance catheter and recorded together with LV pressure and ECG signals. The system has 14 modules and runs on a PDP11/73 computer under the RSX operating system. Interactive signal processing is done with a TeK4010 graphical terminal. Graphical output is on a laser printer. From the raw data, episodes of beats are created. Sets of beats can be composed from one or more episodes. With the aid of this system PV data are processed during a load manipulation in order to assess intrinsic LV pump performance. As an example, a recording pertaining to a study of the effect of an ACE inhibitor on the systolic LV pump performance is presented. A beat set out of an episode of preload manipulation by release of balloon occlusion of the vena cava inferior is displayed. LV systolic pressure and stroke volume are increasing gradually during the contractions. Some characteristics of each beat are shown