Frequency response of fluid-filled catheter-micromanometer systems used for measurement of left ventricular pressure.

The resonant frequencies of five commonly used fluid-filled catheters connected to a solidstate microdisplacement pressure gauge were 18 to 33 per cent higher than those obtained with a conventional manometer. Four catheters had a flat amplitude response to 26 Hz. or more at the 20 per cent amplitude distortion level. The dynamic response characteristic of certain fluid-filled catheters used with microdisplacement pressure gauges allows one to record high fidelity left ventricular pressure curves.