It’s been a pretty tough day.

You’ll recall from yesterday that today was the second day of my cardio stress test.  The treadmill day.  I was a little apprehensive, as I really do not like the device, and stay as far away from them at the Alaska Club (the fitness gym Heather and I belong to) as I can.

The day started innocently enough.

Rich, the nuclear med tech, started out the day as yesterday, with a gamma ray emitter injection.  A short wait then it was off to the treadmill.

The object of this day of a cardio stress test, in case you’ve never had one, is to crank your heart rate, measured in beats per minute (BPM), most of the way up to the max exertion you are supposed to be able to tolerate, then watch EKG readings for any abnormalities.  The max BPM is calculated according to as follows:

Now, a doctor will tell you that this formula is just a guide.  For a young athlete it may be adjusted upwards.  For an old geezer like me, it will almost certainly be lower.  Per the formula, though, my max BPM is 220-63 (my age, unfortunately), which is 157.  So the test was likely shooting for a BPM of 130-135 or so to take measurements at.

The short story is that I made it to 130 or so and was doing great.  My EKG waves started and had stayed picture perfect.

My GP doc, Natalie Beyeler, was there, encouraging me along.  When they cranked up the treadmill to the next level, though- steep grade and I was almost running at this point- my BPM went to 135 and then my oxygen saturation levels suddenly crashed, sending the heart readings haywire.  The O-sat level hit 85 and Dr. Beyeler stopped the test, although I was able to continue to walk all the way through about a two minute “cool-down” phase at a slow speed and on a level grade.

The bottom line is that, while my heart appears to be doing great, my lungs just aren’t (right now at least) doing their bit.  I will probably do just fine on the flat or up mild inclines on the road, but it is clear that my ability to climb real hills and then mountains is in question at this point.

So my doc has scheduled a few more tests next week.  On Wednesday, the 12th, I’ll have a pulse-oximetry test, an echocardiogram, and a pulmonary function test scheduled one after the other.  On Friday we’ll have the results and Doctor Beyeler and I will confer further.  We’ve known all along I’ve had asthma in the background and my O-sat level usually sits around 93 or 94, which is a tad lower than it should be at my age.  I’ve never smoked, worked in a coal mine, played with asbestos, or done other stuff knowingly that would damage my lungs.  I did have severe childhood asthma, though, and have carried around a rescue inhaler (which expire before they are ever used) for years.

So I won’t go into options or courses of action at this point, I’m pretty raw still over this happening, and it is no time to make significant decisions, especially since I’ll have much more information by the end of next week.  I did go out tonight and bought, at Wal-Mart of all places, a middling good oximeter- the device that they clip on your finger at the start of a doctor’s appointment- to measure O-sats during rides and workouts.

The device, which measures continuously, was just a little less than $36.  Over the course of a 45 minute ride on the exercise bike at moderate resistance at a ten mile/16 kilometer per hour speed, it never went below 92 and hit 95 a couple of times right before the end of the workout.  I was more focused on breathing deeply than I had been, but this just confirms my sense that the long almost flat weeks of The Long Warm-Up section of my planned route (The Atlantic Coast to Little Rock, Arkansas) is my friend.

Any thoughts?

David Edgren