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Friday, September 21, 2012

My Life at 9200 rpm's: Can you smell the elephants?

     As a kid in Chicago, I looked forward each Spring to the circus coming to town. Beginning a week beforehand, the newspapers heralded the arrival Ringling Brothers, Barnum and Bailey's "Greatest Show on Earth" big top circus.  

     It literally rolled into town on a special train, followed by a parade of the troupe and the animals and their keepers.  At the time, I lived with my family on the South Side of Chicago.  For me, the circus was always worth the wait.  I liked the clowns and animal acts best.

     Most years my dad took me and my brother to the circus. There was always too much to see, hear, and experience.

     Several times I watched the circus parade through the Loop but the most fascinating spectacle was watching the circus elephants help erect the Big Top. I watched it for three years at least ending in the early 1950s. 

     It was in 1952 or 1953 the circus decided not to set up on the city's lakefront south of Soldier Field. Since about 1919, the circus had occupied essentially the same place in the parking lots adjacent to the south end of Soldier Field. I don't know what happened but the Chicago Park District and the circus apparently couldn't reach financial terms.  

     After that, the circus moved indoors when it came to town, first to the Colliseum and then to the International Amphitheater at the Chicago Stock Yards and finally to the northwest suburbs. It was never the same without the wind blowing off Lake Michigan. The big top seemed to have its rightful home at water's edge.

     At any rate, the day the last big top went up in Chicago, we arrived in the afternoon at the lake front site.  We watched for the last time as  elephants with their keepers, and assorted workers assembled the tent and raised it from a huge segmented pile of canvas to about 70 feet at its peaks. 

     What seemed like chaos, produced a weather tight shelter and stage for three hours of wonderful show biz. I recall five rings but could be wrong. It was a weekday but I don't recall missing school to see the tent go up. 

     The elephants hauled canvas, ropes, and support poles. The loads were tremendous--hundreds and hundreds of pounds.  I  cannot recall exactly but there must have been three dozen elephants at work. 

     Their keepers, by turns, coached and prodded them to work cooperatively to hoist the canvas and erect the poles.  The elephants moved the heavy loads of canvas and held tremendous poles in place while workers drove stakes to tie down the poles holding up the canvas.

    The elephants seemed to work easily and relatively quickly because it seemed like the whole process only took a couple of hours.

     We stayed to see the first show.  I recall the ringmaster's standard spiel, in which he invited "ladies and gentlemen, boys and girls, and children of all ages...your attention please."  

     Then he would direct our attention to the center ring for whatever extravaganza was about to mesmerize a seven or eight year old and anyone else who cared to be transfixed by the colors, action, sounds, music and the smell of the elephants.  When I think about it, I can still smell the elephants.

Thursday, September 13, 2012

My LVAD life at 9200rpms: LVAD support group situation report (SITREP)

    Since September, 2010, I have been attending monthly gatherings in Fargo of those who have LVADs and some who have had heart transplants.  For those seeking an LVAD, know that if the implant is successful and you get to go home, the sailing will not necessarily be smooth.  

     For some of us, it takes months to feel relatively normal.  Regular exercise and healthy diet help.  Attitude is key.

     Fortunately for me, my LVAD and body are compatible or as one of the Mayo Clinic cardiologists said, "you tolerate the pump well."  Heck of an endorsement, right?  I've talked about this before but strokes and drive line infections kill LVAD owners more than any other complication.

     The LVAD support band brothers and sisters at Sanford is a mixed group by education, age, and work history.  What we all have in common is an appreciation of life, what we've overcome, and a sense of gratefulness of each day.   

     In early 2010, the FDA approved Thoratec's HeartMate II for both destination therapy and transitional or bridge to transplant therapy for end stage (read ready to die) congestive heart failure patients. No other LVAD maker can make that claim. 

     Even though I've had mine since April 2, 2010, I am under no illusions about their capabilities.  Heart pumps are not fool proof. While no maintenance is required,  they are machines and can fail. 

     An LVADs meds need to be monitored closely.  The meds generally are to control blood pressure, and heart rate, and to try to ensure that an LVADs blood supply has a slower clotting rate than normal.  The pump cuts up red blood cells, technically called hemolysis, which can lead to anemia.

     Strokes and dizzy spells were discussed at the most recent meeting.  As I understand it, blood pressure for LVADs is maintained lower than it is for healthy hearted people to ease the ability of the heart pump to do its work.  When a person's blood pressure is kept low, standing suddenly can cause dizziness or fainting.

     Several of the dozen LVADs have experienced dizziness and fainting.  One participant who has had a heart transplant approaching eight years, said simply that he has purposely made himself get up more slowly.  Makes sense.  Who remembers to rise slowly every time.  Events happen.

    Another group member has experienced his second stroke as an LVAD.  It hospitalized him for some time.  He reported that his doctors at the University of Minnesota attributed the stroke to hi LVAD breaking down or cutting up red blood cells.  The cells collect and cause a clotting effect.  I'm not a physician or an engineer, but the explanation seems valid.  

     So the question becomes How does an LVAD owner guard against a stroke?  There is no simple answer, I'm told.  Pump speed can be reduced.  Mine is set at 9200 rpm's as the top end based on Mayo Clinic's experience that higher pump speeds cut up more red blood cells. Conversely too low a pump speed can lead to clotting and other serious even fatal incidents.  But without the pump, I and other LVADs would be only a memory to our families.

    Drinking fluids,  staying hydrated, is also critical. The Camelbak company that supplies water reservoirs you carry with you had a slogan that is more true for LVADs than thirsty hikers:  Hydrate or Die.

    Maintaining an INR (International Normalized Ratio) within the range prescribed for LVADS is another factor.  A normal person's INR is about 1.0.  My INR range is 2.0 to 2.5. My friend's must be maintained above 3.0. These elevated INR levels help keep our pumps from having fatal clots.  

    I have a home monitoring kit with which I test my INR once a week and report the results to the Sanford Anti-Coagulation Clinic and the kit's manufacturer.

    In many ways, LVADs are pioneers.  We are the few in daily experimental mode.  Over 10,000 HeartMate II pumps have been implanted world wide.  I don't think about being a pioneer.  It's enough to be here in 2012.  If my LVAD gets me to the point where I get the gift of a heart, that will be a good thing.  Meanwhile, I'm good.  Never quit.

Monday, September 10, 2012

My Life at 9200 rpms: Last gasp of a drowning man?

     Sunday dawned with no wind on the lake.  Son Kevin launched the small boat, a 12 foot Porta Bote, with newly minted six horse outboard attached.  

     I've been in the boat for jaunts (slow) up and down the lake shore, fly casting for bass.  But we never opened her up.  

     There were finally 10 hours on the engine and its break in time was up:  full speed ahead.  This was a first.  He was alone.  The "all stop" emergency cord dangled in the stern.  

     The "all stop" plastic clip has to be in place  for the engine to run.  The object of the clip, which is attached to a short tether and snaps onto the driver's pants or vest, is to stop the engine if the driver goes into the drink because he's yanked the clip from the engine.

     For this run, Kevin tightened a screw in the throttle handle that disabled another safety feature.  This feature automatically engages a spring that returns the throttle to low idle speed when the handle is released just like a motorcycle throttle.

     As he sped along at top speed--15 to 18 m.p.h.--he changed course slightly. The swerve was minimal but that was enough to cause the boat, which has a dry weight without engine or seats of 65 pounds.  

     He was thrown unceremoniously and unexpectedly from the boat into 15 feet of water. In the condition he left it, the unmanned Porta Bote, like most motor boats, travels in circles.  He recovered enough in the water to see the boat bearing down on him head on.  

     As it was passing, he was able to grab hold and haul himself back into the boat and shut down the engine.  Without adrenaline and mental quickness, he could have been run down and likely  raked by the propeller.  Hence the working title of this post. 

     We have some new, (read "standard") rules now:

     1.  Any one driving the motor boat must wear a life jacket.

     2.  The emergency stop clip must be attached to the driver or his life jacket.

     3.  The driver must be aware that slight changes in course at high speed in this water craft can have big consequences.

                                      *     *     *     *

     LVADs can go boating and fishing but must take good care.  Disaster lurks because we are not waterproof.  If the electric power is interrupted, it might be our last gasp.  Tight lines, fly fishers.

         


Monday, September 3, 2012

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.