Life at 9200 rpm's: 29 months and counting

     I am fortunate to report that I am 29 months into my life at 9200 rpm's, the set maximum speed of my LVAD.   The pump's speed causes more than five liters of blood to circulate through me every minute.  The pump powers life itself.

      The illustration below, the one in blue tones, depicts the typical setup of an implanted left ventricular assist device.  Some of the equipment may not be obvious to those who have never seen it.  In the upper left quadrant is a representative heart with grey and white tubing attached to a small device below the reddish heart.  

     The small device is a HeartMate II.  The line stemming from the lower part of the pump is a percutaneous electrical lead that traverses the abdominal cavity and exits on the left side of the abdominal wall.  The percutaneous lead attaches to the HeartMate II system controller.  

     The controller is depicted as the oval-shaped device at about belt level with three electrical leads attached: the percutaneous lead, and a lead from each of two batteries.  The batteries are depicted in holster like devices suspended from the shoulders of the fictional patient.

 The illustration appears on the Thoratec Inc. website.

These illustrations show the system in operation and label significant parts. The various parts are not shown to scale and in the illustration showing the external battery pack, only a single battery is shown.  But the overall notion of how it works is accurate.  The orange arrows show the direction of blood flow. Stanford University's website displays the illustrations.

     In the right hand illustration, the internal mechanism of the LVAD is shown.  The rotor is the only moving part.  There are ruby bearings at each end of the rotor.  The  rotor works is an Archimedes screw.  The rotor fits snugly inside the pump housing.  The rotor has external threads that cause blood to flow as the rotor turns.

     The point of this discussion is to underscore the engineering marvel of this miniaturized system.  Early versions were larger and had more moving parts.  More failures occurred.  One friend who had an earlier LVAD .model could be heard coming down the hallway.  Now the pump is silent. 

      The HeartMate II, I'm told, has never failed.  That is not to say that LVAD owners don't develop complications like strokes and "events" that cause significant medical problems.  The point is that the pump works well.  As of mid-April, 2012, 10,000 HeartMate II LVADs have been implanted worldwide.

      As I wait on the University of Minnesota's heart transplant waiting list, I am confident in my HeartMate II, No. 8358, established April 2, 2010.