Major organ function under mechanical support: Comparative studies of pulsatile and nonpulsatile circulation

We examined a major organ function during 3 h biventricular assisted circul ation after acute myocardial infarction model in the pig. In left ventricul ar circulation, the outflow cannula was placed in the ascending aorta and a n inflow cannula through the mitral valve in the left ventricle. A pump (pu lsatile group, Zeon Medical, Inc., Tokyo, Japan and nonpulsatile group, Nik kiso HPM-15, Nikkiso, Inc., Tokyo, Japan) was connected to each cannula. In right ventricular circulation, the outflow cannula was placed in the pulmo nary artery and an inflow canula in the right ventricle. The right ventricu lar circulation was supported by a nonpulsatile pump (Nikkiso HPM-15). The items measured were the regional blood flows of the cortex and medulla in t he kidney, white matter and gray matter in brain, and liver; renal arterial flow; carotid arterial flow; portal vein flow; common hepatic arterial flo w; arterial ketone body ratio (AKBR); and lactate/pyrubic acid (L/P). In th e pulsatile group, the renal cortical blood flow increased, and the medulla blood flow decreased. On the other hand, in the nonpulsatile group, both r egional blood flows decreased. That means that in the pulsatile assisted gr oup intrarenal redistribution improved rather than in the nonpulsatile assi sted group. In addition the liver regional blood flow, AKBR, and L/P showed significant differences between the pulsatile and nonpulsatile groups. On the other hand, the white matter and gray matter regional blood flows and c arotid arterial now did not show significant differences between the groups . The results of our study indicated that pulsatile circulation produced su perior circulation in the kidney and liver, and microcirculation on the cel l level was superior as well in early treatment of acute heart failure.