The development of mechanical assistance to the failing human heart.

Mechanical systems designed to support the failing heart temporarily or permanently are briefly described. Of these systems, most are still in the experimental laboratory, but several devices have had limited trial in patients. One for temporary use, the intra-aortic balloon pump, is now routinely used as adjunctive support for selected patients undergoing open-heart surgery. The development of these systems followed experimental demonstration that by manipulating arterial pressure and flow, it would be possible to increase coronary blood flow and diminish left ventricular work.