Functional heart replacement with the spindle pump: first results. The spindle pump is a nonpulsatile blood pump with a double function, i.e., it works centrifugally and represses simultaneously. The first experiences with this type of pump used as a biventricular assist device in four short-term animal experiments (up to 13 hours) are described. It can be demonstrated that in cases of a normally beating heart, this BVAD decompresses both ventricles by 60-70%, while the aortic pressure is slightly increased; on the other hand, in case of ventricular fibrillation, the BVAD with two spindle pumps maintained the entire circulation, at an arterial pressure between 80 and 90 mmHg with a flow volume between 3.5 and 4 L/min. 