Analysis of the arterial blood pressure waveform using fast fourier transform technique during left ventricular nonpulsatile assistance: In vitro study

The arterial blood pressure waveform is variable during left ventricular as sistance. The aim of this study is to examine the correlation between the l eft ventricular assist device (LVAD) condition and the arterial blood press ure waveform in a fixed cardiac output condition using a mock circuit. This mock circulation loop was composed of an aortic compliance chamber, a left atrial compliance chamber, a pneumatic pulsatile pump as a native heart, a nd a rotary blood pump representing the LVAD with left atrial drainage. The Fast Fourier Transform technique was utilized to analyze the arterial bloo d pressure waveform and calculate the pulsatility index (PI) and the pulse power index (PPI). The PI and PPI decreased with the increase of the LVAD r otational speed, exponentially. There was a significant negative correlatio n between the PI, PPI, and the LVAD rotational speed, flow rate, and assist ratio. The best correlation was observed between the PPI and the assist ra tio (r = 0.986). From this viewpoint, an ideal LVAD condition may be estima ted from the pulsatility change of the arterial blood pressure waveform.