Experimental study of sympathetic nerve activity in animal with total artificial heart

Abstract

In order to determine the effect of total artificial heart on autonomic nervous system, renal sympathetic nerve activity (RSNA) were analysed by the use of power spectrum and coherence function. Two pneumatically actuated sac type ventricular assist devices were implanted as biventricular bypass (BVB) in animal experiments. After the BVB pumping, natural heart was electrically fibrillated to constitute a BVB type of TAH model. After the left frank was opened bipolar electrode was attached to the left renal sympathetic nerve via retroperitoneal approach to detect the RSNA. Values of the squared coherence between the arterial pressure waveform and RSNA were measured at the same frequency level of cardiac rhythm and VAD pumping rhythm. With the TAH pumping, coherence spectra at the cardiac rhythm frequency was decreased, and the coherence at the pumping rhythm frequency was increased. These results indicate that arterial pulse wave which was made by TAR contributed to the postganglionic sympathetic activity.