Ventricular assist devices were first designed 30 years ago, at a time when open heart surgery posed a real challenge and the early postoperative mortality was near 10%. The designs of the pulsatile devices have not changed very much, being basically membrane pumps available in the form of a sac (Portner) or a moving diaphragm (Pierce, Unger, Frazier, Whalen) (Table 1). The driving source is either pneumatic or electromechanical via a tube through the skin. In the electromechanical driving mode, the incorporated devices need a compliance chamber. Furthermore, nonpulsatile blood pumps are also available.
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