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The Mysterious Human Heart The Mysterious Human Heart border=
A Series by David Grubin


The Replacement Heart
VentrAssist Diagram and Rotor
(Left) A diagram of the essential parts (Right) A 3-D image of the VentrAssist's rotor


Photo of the VentrAssist left ventricular assistance device
The VentrAssist left ventricular assistance device.
Images courtesy of Ventracor, Inc.
In 2004, clinical trials began in the UK for the VentrAssist device, designed by the Australian company VentraCore. The VentrAssist is part of a group of heart devices known as LVADs (left ventricular assistance devices), which do not replace the heart but, instead, are implanted underneath the rib cage, alongside the heart, to augment the pumping action of the left ventricle.

Most LVADs use a pulsing motion to circulate the blood, mimicking the motion of the heart. The complicated designs necessary to emulate the heart's function make the devices prone to failure and can cause blood to pool and clot, leading to strokes. LVADs are often used as a last resort.

The VentrAssist has only one moving part, a hydrodynamically suspended centrifugal rotor, that drives a continuous stream of blood and is six times smaller than the standard LVAD. Magnetic fields created by copper coils cause magnets to push the blood through the pump. Blood comes through a tube from the left ventricle and back out to the aorta. The continuous flow of blood reduces the risk of clotting by preventing the blood from stagnating. It also has a side effect: patients with the VentrAssist have no pulse.

The VentrAssist is currently in trials with the FDA for approved use in the United States.


Funding is provided by Medtronic, AstraZeneca, and Mars, Incorporated - makers of CocoaVia. Additional funding is provided by the Fannie E. Rippel Foundation. A co-production of David Grubin Productions, Thirteen/WNET New York and WETA Washington, D.C.
Medtronic AsrtaZeneca MARS Thirteen/WNET NEW YORK