Initial experience with a thin single segment pressure and conductance catheter for measurement of left ventricular volume

A thin and soft multifunctional catheter was evaluated for the simultaneous real time monitoring of left ventricular volume and pressure with special consideration to side effects such as interference with normal cardiac electrophysiology. In four pigs, pressure and volume were simultaneously recorded by using the thin single segment pressure and conductance catheter. Measurements were done under varied cardiac conditions: at baseline, during preload reduction and afterload increase. Volumes were calibrated with intracardiac ultrasound measurements. During preload reduction the pressure and volume decreased as expected. A cautious afterload increase resulted in a corresponding pressure and volume increase, the maximum of the pressure curve changed from early to late. Both SV and EDV increased. The very few arrhythmias were mainly caused by surgical interference. The present study demonstrates that our thin single segment conductance catheter for the simultaneous measurement of LV volume and pressure has a performance that warrants further development with the goal of making the method available for human use. In particular, the catheter did not cause any arrhythmias.