A new left ventricular assist device: clinical experience in two patients.

A permanent parallel aortic pump (PAP), essentially a permanent intra-aortic balloon pump or modified dynamic aortic patch, has been designed to support failing left ventricles The PAP is a counterpulsation system in which an external energy source delivers a pulsatile wave into the central circulation during cardiac diastole and relaxes during cardiac systole. Clinical improvement occurred in two patients after PAP implantation. The initial regimen of continuous pumping evolved to intermittent left ventricular assistance, and the patients were able to be periodically disconnected from the pump and ambulated. The patients expired 39 and 34 days after implantation due to gastrointestinal bleeding and complications of chronic emphysema and tracheostomy. Autopsy revealed that surgery for both devices had entirely healed.