Fluctuations of the hemodynamic derivatives during left ventricular assistance using oscillated blood flow

To analyze the autonomic nervous system during left heart bypass with a vibrating flow pump (VFP), fluctuations in hemodynamic derivatives were evaluated by the spectral analysis method using fast fourier transform methodology. After the left pleural cavity was opened through the fourth intercostal space under general anesthesia, a VFP was implanted as the left heart bypass device in chronic animal experiments using 3 healthy adult goats. Hemodynamic parameters with and without VFP assistance were recorded on magnetic tape in awake animals and were analyzed by computer through an analog to digital convertor. Power spectral analysis was performed on a beat-to-beat basis for the evaluation of the fluctuations. During left heart bypass with the VFP, Mayer wave fluctuations were decreased significantly although respiratory waves were not changed significantly. These results suggest that sympathetic nervous system modulation was changed under the influences of the left heart bypass with VFP. By using this analysis methodology, truly physiologic ventricular assistance may be achieved.