Real-time pressure-volume diagrams for the evaluation of ventricular function

Using three intraventricular diameter signals obtained from ultrasonic distance gauges and applying the general ellipsoid model to the left ventricle, it was possible to obtain the left ventricular volume signal. Implanting a miniature transducer in the left ventricle the pressure signal was attained. With these two signals the pressure-volume diagrams were constructed on line, and ventricular function during load manoeuvres could be studied from them. Because the whole process was done on line, using a microcomputer, the performance of the left ventricle to load manoeuvres in different conditions could be seen instantly.