A pneumatic TCI LVAD was implanted prior to the experiment. The rate of the LVAD was controlled externally from a PC with a NI LabPC+ DA card, using custom made LabView VI. The femoral pressure was measured with a Millar pressure catether.
The rate was initially set to 80 beats/min and then decreased by 5 beats/min every 1 minute. The minimal rate was 46 beats/min.
The picture below shows a portion of pressure waveforms recorded.