[Systemic error during measurement of dp/dt using conventional heart catheters and their correction]

The influence of 4 different types of conventional cardiac catheter on the systemic error during measurements of dp/dt was investigated by testing the frequency response. This was done by coupling on end of the fluid-filled catheters to a newly developed sine wave pressure generator (0-100 Hz), and the other end ot a pressure transducer (Statham 23 Db). The obtained electrical signal was preamplified and differentiated by means of a differentiation amplifier (linear rise up to 20 Hz). Also investigated was to what extent the dp/dt registration (UV-Oscilloscope) could be improved by damping the signal by means of electrical low pass filters.