Robert’s Heart

It’s a new year and there’s no better way to start it off than with a few more arrhythmias.  I’ve had palpitations regularly over the last couple of months.  That seems pretty normal and I’m getting used to having the SVTs every few weeks.  Mostly they are pretty minor but seem to be worse when I’m stressed like when I’m entertaining over the holidays.  Usually they get worse the week after a stressful time.  This week I’ve been having them pretty regularly and got a chance to record one today.  For today’s SVT you can view the Start (CLICK HERE FOR ECG) and End (CLICK HERE FOR ECG).  Both of these are the Lead II view.  This SVT ran about 220 beats per minute and lasted about a minute and a half.

On another note… earlier this week I spilled a bit of freshly brewed hot coffee on my hand.  It hurt, but more interesting was that my body reacted within a second or two by having an immediate and strong SVT.  After dealing with the coffee spill I took a moment to perform a vagal maneuver to convert the SVT back to sinus.  I tend to hold my breath with preasure and slowly let it out concentrating on the beats pounding in my head.  This almost always works for me to convert the SVT.

I’m an electronic engineer by trade and a software engineer by training.  My cardiologist is not so different.  Our jobs are that of problem solvers.  To solve a problem:  1) Gather evidence,  2) Make an intelligent, educated guess,  3) Apply your educated guess.  The more empirical the evidence is the more accurate the guess is.  Don’t confuse engineering (the application of science) with science (the fact of knowing something).  In the cardiologists case it is obviously important to base your decisions on the best information possible.

In my last post, It’s My Heart I left off with my doctor having diagnosed me with vasovagal syncope.  Knowing this is wrong, I awoke at 4am and couldn’t sleep trying to figure out how to get a correct diagnosis.  I need to prove with empirical evidence to another engineer that my problem is rhythm related and not a reflex problem.  It comes down to being able to capture my issue on an ECG strip.  I either need to purchase or build an ECG machine.  My search revealed no consumer grade ECG machines which produce anything usable for less than $500.00, at least not that I could find.  I then searched for plans to build an ECG machine and I immediately came across this Scientific American Article.  It described a unit which amplifies the heart’s signal while not amplifying noise.  The output is a 1 volt peak-to-peak signal.  I then needed a way to capture this signal.  It didn’t take me long to remember that sound cards capture audio in a range that is compatible with a 1 volt peak-to-peak signal.

I spent some time on the internet and at the local electronics shop to purchase all of the parts needed.  I also needed some stick-on ECG electrodes to connect the leads to the skin.  Fortunately there are many sources for these on the internet.  For about $15.00 I purchased a pack of 50.

After building the ECG electronics and doing some limited testing I connected it up to my PC sound card and began to capture the data with the open source audio software Audacity.  This software is awesome software for novice and professional recording artists alike.  But the fact Audacity is free and graphs the audio signal were the overriding factors for me :-).  I hooked it all up and there is was.  An ECG:

Audacity ECG

At the time, I hadn’t realized how important using Audacity to capture the signal was.  It turns out that the filters available in Audacity are very important and allow me to cleanup any remaining noise in the signal.  Additionally I can capture hours of data then select only the sections that are important for review.

When I finally captured an SVT on the machine (4 months later) I needed to present this to the doctor.  My mom, a cardiac nurse, reviewed the data with me.  She found it difficult to review the data in Audacity because she had been trained as a cardiac nurse to read them on strips which have a graph paper background with specific timing.  Without this it is difficult to determine all of the important timing parameters of the ECG.  To present this data to my doctor I needed to convert it to strips he understands.

To convert from the raw audio data to a graphic strip I wrote a Perl script.  It converts 6 or 30 second audio captures into GIF files which are easy to print.  The script maps the audio timing onto the graph paper background that provide a reference for medical professionals.  All of the ECGs you see on this site were converted with this script.  Click Here For an Example

In the end the cardiologist acknowleged the SVT and we were back on track.  Still the diagnosis is “benign” SVTs.  While the word “benign” is great news they still don’t feel benign.  After time and time again being told they are benign I’m learning to live with them.  We are also trying to control them with meds.  More on the meds later.

It’s my heart and my health.  My way of handling medical issues which I think are scary or threatening to my lifestyle is to learn a lot about the subject, and to ask intelligent questions of my doctor.  Then to question everything that doesn’t make sense.

After my first salvo of SVTs I saw my cardiologist for the first time (July 3rd, 2007).  He is specifically a rhythm specialist (or cardio electrophysiologist).  At his suggestion I started wearing a heart monitor for the next month.  Unfortunately the issue did not come back during the month.  He suggested the possibility of vasovagal syncope.  That is, passing out (or nearly in my case) due to a sudden drop in blood preasure after standing up (or other like event).  I tried to explain to my doctor that this didn’t sound like my problem and that I had never had any problem like this.  However I didn’t mind eliminating a variable.  So, we agreed to do a tilt table test.

Tilt Table Test - The tilt table test is an outpatient procedure.  I showed up at the hospital and was prepared by changing into one of those flattering hospital gowns.  After a few minutes I was transferred to the room where the test would take place.  It is exactly what you expect.  After laying down and being hooked up to a 12 lead ECG the table is tilted up, but not so you are standing.  Instead it’s tilted to about 80 degrees so your weight is distributed between the table and your feet.  This sounds easier than it is.  When standing you normally tense your legs which counteracts the blood pooling in your legs.  When on the tilt table your blood still flows down, but your legs aren’t tensed up enough to counteract the pooling.  So, your blood pressure drops.  If after 15 minutes you haven’t passed out then they give you a dose of glyceryl trinitrate (A.K.A. nitroglycerin).  This causes your heart to race and exacerbates vasovagal syncope.  If you pass out during the test then you probably have it.

After 15 minutes I did not pass out (I was really tired of standing though and my feet hurt).  So they gave me a spray of the nitroglycerin.  I immediately felt the rush and my heart raced.  Another 5 minutes went by and I decided to rest my eyes and relax.  At that very moment my doctor exclaimed “Ahah!”  I opened my eyes and said “what.. what did you see?”   He quickly calmed down and said “no… just thought I saw something on the monitor.”  So I went to rest my eyes again and exactly the same sequence occurred.  At that time I realized I’d have to keep my eyes open or face the false positive diagnosis.  Instead… I made it through the 30 minutes and my doctor, despite my protests, declared this a false negative and made the diagnosis vasovagal syncope.  In fact he quoted the statistic of 14% false negative with this test.  DOH!

That seemed rather anti-climatic and somewhat disturbing.  On the one hand I didn’t pass out.  On the other I am still no closer to a correct diagnosis than before and my doctor has given up on trying.

At 4am I awoke from my sleep and could not return.  On my mind was the clear problem of how I could acquire a correct diagnosis.  Without an ECG of this phenomenon I would not be able to prove it.

And so on the internet I searched…  To Be Continued

It’s been 2 weeks since my last post when I was waiting for my cardiologist to call with MRI results.  He actually called about 2 hours after the last post but my vacation got in the way of this update.  Anyway it turns out that all of the “abnormalities” are not an issue.  The aneurysm is very small and because the muscle wall thickness is normal it doesn’t pose any danger.  The akinesis is for a small area and doesn’t pose an issue.  The 40% ejection factor is still within the normal range for this MRI.

So the final word is “All Good.”  We will continue to monitor these issues by echo cardiogram every couple of years to make sure they aren’t getting worse.

Now that my cardiologist has had his word…  I’ll likely get a second opinion.  I really don’t expect to get any different answer, but it still helps to have correlation.

Last week my cardiologist was on vacation and I was curious about my MRI results. So, I called the imaging center and asked them to fax me a copy of the report. They can’t do that without my doctor’s OK. Hmm… I’m pretty certain I have a right to my medical records, but I’d rather get them than fight about it. So I asked if they could fax them to an alternate doctor and the answer was absolutely yes. So, I had them fax it to my aunt who is an M.D. Not much to my surprise, the records showed up on my fax within a few minutes.

I read the report and I was surprised to find that there were some abnormalities observed. I truly expected that, after all the other tests, there would be nothing of interest on the MRI. A few of the terms are downright concerning (at least from my perspective).

“Aneurysm,” “borderline systolic,” “akinesis” were all used to describe parts of my right ventricle. The report also indicated a 40% ejection fraction for the right ventricle which is marginal at best.  I should add that the “aneurysm” was qualified by a normal cardiac wall thickness (the thickness of the muscle) which indicates the aneurysm is likely an artery.  From my “google understanding” coronary artery aneurysms rarely burst because they are supported by the pericardium (the sack which surrounds the heart).  That makes me feel a lot better… really.

After discussing with my aunt we agreed that there was probably no reason for immediate concern. However I should contact the cardiologist’s office and make sure that the covering cardiologist has reviewed the results.

Their office had not reviewed the results and I had to specifically indicate that I knew something was abnormal and that they should probably review it to make sure it wasn’t an emergency issue. The covering cardiologist did review the report and indicated it could wait for my cardiologist to return.

So now I wait

As of today, Tuesday August 19th, I haven’t yet heard from the cardiologist. I’ll give his office a call today to see if I can get some results.

WOW!  Didn’t expect the cardiac MRI to last that long.  One hour and fifty minutes is a long time to have to lay still on a cold hard table.  The technician set  me up with some tunes (Pink Floyd, Dark Side of the Moon) to pass the time, but my arms got tired quickly of sitting in one place and it got really uncomfortable real quick.  Not to mention that breathing in and holding my breath for 15 seconds out of every 30 seconds was starting to make me a bit loopy.  I knew it was getting long when “Breathe” came on for the SECOND time (no reference to my breathing in and out over and over intended… really).  Then “Time,” and “Money” for a second time.  “The Great Gig in the Sky” was in there too, but you can’t help but remember the beginning of both “Time” and “Money.”  He then switched me to some U2… a nice change, but I’d like to be off the table.  Anyway, this post is starting to feel like my time on the table.  I’ll be picking up a copy of the MRI on CD.  I don’t know if I can make it available on this site yet.  If I can I will.

At about 75 minutes into the MRI the tech got the imaging center’s cardiologist to come look at the photos.  Presumably to check and see if there was anything of interest which needed further imaging.  After about 15 minutes of waiting we got back to it and took a bunch more images.  Seems there was some question about what could be fat in or around the pericardium.  Unfortunately I don’t really remember the conversation that well.  So I’ll, uncharacteristically, wait for the results instead of guessing

I just received a phone call from my cardiologist (actually a cardiac electrophysiologist). He called to review my Nuclear Stress Test results. All good news! Stress test itself showed no arrhythmias and the tomographic images showed good blood flow to the heart. This indicates that the arrhythmias are not life threatening. This is what I expected, but still good to have positive evidence :-). I’m still going to do the cardiac MRI next week to rule out any other issues. I’ll post those results when I have them.

So, on 12/30/07 I finally caught an SVT on the monitor (ECG: 12/30/07 SVT), that’s great. The problem is, that evening, I kept having them. While it was a bit uncomfortable it did give me an opportunity to capture some good information. Later in the evening on 12/30 I was monitoring myself when I caught a complete SVT and more… This SVT was particularly painful and had a feeling of significant pressure in my chest in addition to the usual light headed feeling. At about three and a half minutes into the SVT the pain and pressure went away, but I still had the arrhythmic feeling in my chest. The ECG still showed an arrhythmia, but it wasn’t regular like the SVT. The next morning my mom identified the irregular rhythm as Atrial Fibrillation. FYI My mom is a retired cardiac care nurse who has been a big help for me to understand (in a novice kinda way) what I’m looking at on the ECGs.

This strip (Click Here For The ECG) shows the beginning of the SVT. At about 14 seconds on that strip a “glitch” in the SVT causes it to speed up from what was 190 BPM to 232 BPM. That’s when the SVT became particularly uncomfortable.

This strip (Click Here For The ECG) shows the conversion from SVT to AF. It is pretty noisy because I was moving around at the time. After a few minutes the AF settled into about 140 BPM (Click Here For The ECG) and lasted for at least 15 minutes when I stopped monitoring. It did eventually, spontaneously, convert to a sinus rhythm.

I built the little ECG machine to capture an episode of supraventricular tachycardia (SVT) for the doctor. After waiting several months for something to occur I captured this SVT on December 30th 2007. It lasted several minutes. This SVT ran at about 220 beats per minute. This strip shows the last 2 seconds of the SVT and the conversion to sinus rhythm: Click Here To View

One of the first recordings I took with my homemade 3 lead ECG is this one. I took it on August 26th 2007.  It is a normal rhythm:  Click Here To View