Wednesday, September 11, 2013

Normally abnormal.

Athlete's Heart vs. Cardiomyopathy, from http://impruvism.com/athletes-heart-1/


The image above is about my heart, ARVC and the results of a recent round of testing, including an MRI. But let's skip to the part where I get an MRI with metal hardware in my chest that basically controls my destiny. This has got to be lowest-common-denominator interesting because MRI techies would have you believe that any metal you happen to absent-minded meander with into an MRI tube  is going to be ripped off - if not through - your body in some cinematic manner. Apparently this is not the case.

"It's not really about the MRI pulling things around in your body" the electrophysiology fellow who was prepping me for my test told me..."its more about the heat."

This was not the answer I was expecting, nor was it reassuring.

"We try to keep the ICD from heating up inside of you."

So, the magnetic field of the MRI heats metal. Those of you with an ICD know that the unit functions with "leads" - metal wires that are embedded in the heart that detect heart rhythm and deliver pacing, and eventually the shock, should it be needed. One can imagine an unpleasant scenario the medical journals refer to as"radiofrequency-related myocardial thermal damage ".

This did not happen to me. The MRI went according to the book. The tube was claustrophobic, I was nervous, but it all worked out. I prefer to keep my eyes shut once the donut has swallowed me. Knowing I have no ability to move is not such a big deal when I can't see the closeness of the machine. 

After the first half-hour or so I started to enjoy myself. There is a hell of a lot of breath-holding with a cardiac MRI. Apparently this is key to getting good images. I was an easy patient and my case was almost boring, as evidenced by the EP fellow playing Angry Birds as I was wheeled through the control room when it was over.

The results, I would learn later, were pretty encouraging. As a reminder, the MRI was performed to determine if my bout with mycarditis a few months earlier had any lasting effects on my heart. It was also done to see if there had been any degradation to my heart, 5 years after my previous ablations and ICD implant. ARVC is a "progressive" disease that is thought to be negatively affected by exercise. By my estimation I've ridden my bike around 30,000 miles since recovering from my ablations in 2008. In 2009, determined to see if I could get back to a prior level of fitness, I did several bike races on my long-disused "Category 2" USAC license. Since then I've been riding as much as I wish as fast as I wish. Which is not particularly much or fast - but still mostly in the 75 to 95% of max heart-rate zones.
All highly ill-advised by the ARVC specialists.

My MRI showed that my heart was unchanged since my first MRI in 2008. In fact, one particular metric had improved - my Right Ventricle End Diastolic Volume had reduced slightly. This is important because right ventricle enlargement is a major symptom of ARVC, though it was by no means showing that my condition was reversing, either.

The end result was that I am exactly where I was in 2008, heart health and fitness-wise. My heart is a bit more enlarged than a typical athlete's heart, but no more so than before. If ARVC is a progressive disease, I am not progressing. More about what this may or may not mean in a future post...