Tuesday, May 15, 2007

Tuesday May 15, 2007
What is Implantable left ventricular assist device (LVAD)


A ventricular assist device (VAD) is a mechanical pump that helps failed heart pump blood throughout the body. It was destined to used as a "bridge-to-transplant" but it is also a destined therapy for many patients who are not eligible for transplant. Actually, recently it has been reported that LVAD may reverse the heart failure by prolonged unloading of the myocardium causing myocardial recovery ! 1 There are many commercially type pumps available in market but basic idea is the same to help weak ventricle in pumping blood. There are 2 basic kinds available though - Pusatile and continuous (or debakey which is totally implanted inside the body). Parts consist of

1. A pump unit, implanted in the abdomen (very thin patients becomes ineligible)


2. An inflow tube (or conduit), attached to the bottom of the apex of left ventricle

3. An outflow tube, attached to the aorta Internal valves that allow for one-way blood flow through the system

4. Power leads, that pass from the internal device through the skin.

5. External controller and power base unit or battery pack that attaches to the power leads/cables.



The controller is programmed to maintain a specific pump spread. It displays the status of the system and sounds alarms if any. The controller and batteries can be worn in a belted waist pack or a holster under the arm. Or, it may be connected to a power base unit and plugged into a wall outlet.





References: click to get article / abstract

1. Left Ventricular Assist Device and Drug Therapy for the Reversal of Heart Failure - NEJM, Volume 355:1873-1884, November 2, 2006