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Technical FAQ: No burning of my haywire heart

Lennard Zinn explains a recent heart procedure he underwent and why it was not successful.

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One of the ways I process major turning points in my life is to write about them. And given that this one has to do with a subject that touches a disproportionate number of avid cyclists over a certain age and is a subject about which I receive many questions for this column, you get to be the recipients of my musings this week.

Last Tuesday, I went in for a procedure to repair my heart. As many of you are aware, I developed a heart arrhythmia five years ago, which led to my writing a book, “The Haywire Heart” on the subject of cardiac risks for masters athletes with VeloNews’s Chris Case and prominent cardiac electrophysiologist (EP) Dr. John Mandrola. This particular surgery is called an ablation, a procedure in which the arrhythmia is stimulated via drugs and electrical impulses while the patient is on the operating table, and the EP doctor, using catheters inside of the heart, “maps” where the aberrant electrical current is flowing and kills (ablates) some cardiac muscle cells along its path in order to stop it. I had high expectations of success but it ended in failure (for the second time). I have a deep amount of sadness and disappointment about it.

The short story of why the procedure failed is that my doctor performing the procedure could not locate the cells creating the arrhythmia. Since this is a technical column, and some of you may be interested in the technical details, I explain those below. [related title=”More Technical FAQ” align=”right” tag=”Technical-FAQ”]

The other short story is that I had another failed ablation in 2014 when I was more naïve about the process and assumed it would work in the fashion cheerily explained to me going in. This time, I had no such illusions, and I did everything in my power to make sure that my doctor would be able to stimulate my arrhythmia for long enough periods in the OR (or “electrophysiology lab,” as it is euphemistically dubbed) to map exactly where to burn the rogue cells causing my arrhythmia. While aware that it might not work, I thought my heart was sufficiently sensitized to produce the arrhythmia and hold it long enough for him to map it. To ensure this, I was intentionally going into arrhythmia daily while cycling, cross-country skiing, or backcountry skiing, and I even went out for a bike ride that lasted an hour and a half under the nearly full moon at 4 a.m. on January 30th, three hours before my surgical appointment. I went into arrhythmia seven times during the ride.

I had allowed myself to anticipate once again being an athlete without an arrhythmia. While I gave up bike racing and cross-country ski racing five years ago and have no intention of ever trying to be as fast as I can be on skis or on a bike again, there are still things I would like to do that an arrhythmia puts out of reach. For instance, I would love to again lead bike tours in Italy, something that I thoroughly enjoyed doing over many summers with Connie Carpenter and Davis Phinney. A good friend of mine from Vicenza started Scatto Bike Tours last year, starting with a five-day ride from Venice to Rome last June that I was to lead (I used to live between Venice and Vicenza in northern Italy). I believed that my heart would be able to handle it, and I signed up eight friends to ride with me. They ended up riding from Venice to Rome without me due to a staph infection flaring up in my right knee that required surgery, ultimately resulting in bilateral pulmonary embolisms (blood clots in both lungs) that had come up from the leg below the surgery site a couple of weeks before the trip. This year, I really wanted to finally do that ride, and I have a lot of sadness about seemingly having to give up such ambitions for good; there is no way I can do six-hour rides day after day after day with my heart behaving the way it has been recently. And after this ablation failure, it appears there is no resolution for my heart condition. Here is why.

My particular arrhythmia has been diagnosed as focal atrial tachycardia, defined as a rapid heart rate below 300 bpm originating for a focal point in one of the two upper chambers (atria) of the heart. This condition differs from the most common arrhythmia to afflict masters endurance athletes, namely atrial fibrillation (“AFib,” or “AF”), defined as a disorganized, chaotic heart rate over 300 bpm in the atria.

Unlike atrial tachycardia (otherwise called supraventricular tachycardia, “SVT”), the electrical impulses causing AFib tend to originate in the pulmonary veins, the big veins bringing oxygenated blood from the lungs into the left atrium. An ablation for AFib generally consists of burning or freezing cells in the atrial wall surrounding the entry point of those veins into the heart; this creates a ring of dead cardiac cells that block the propagation of electrical impulses from the veins into the heart. Unlike with my condition, performing this ablation requires no mapping of the electrical activity, since the location is where to ablate is known once the AFib diagnosis has been made.

Diagnosing heart conditions is done by analyzing blips on an electrocardiogram (aka, “EKG” or “ECG”), a graph of voltage in the heart vs. time. Since my arrhythmia only appears while I’m exercising, I have a tiny EKG transceiver implanted under the skin on the left side of my chest, right atop my heart, in order to get the most accurate diagnosis possible. This little LINQ Monitor records what my heart does and, at 2 a.m. every day, downloads the file to a bedside transmission device, which then uploads it to my cardiologist’s server.

An atrial tachycardia (AT) more common than mine is called “reentry.” In reentrant AT, electrical impulses circulate in a tight loop within one atrium (whereas normal electrical signals travel from the top of the heart to the bottom and then stop after each beat). Killing cells anywhere along this loop would stop the current flow. Since my AT is focal, rather than reentrant, there is no loop and no “slow or fast pathway” of electrical impulses; the cardiac electrophysiologist has to find the exact ectopic focus (or “ectopic pacemaker”), the excitable group of cells that trigger beats in my heart before the sinoatrial node (“SA” node or “sinus node” in the upper right atrium) can initiate normal beats. It takes some time to follow the aberrant current flow long enough to find this point, and mine never persisted for more than four or five beats while lying on the table in the EP lab with catheters inside my heart.

Since I had this same issue of a lack of sufficient duration of my arrhythmia for complete mapping of it on my first ablation attempt four years ago while under general anesthesia, my doctor and I decided that I would undergo the procedure this time without any anesthesia, in hopes that my heart would be more excitable. Then, in my ski and cycling workouts the last couple of weeks right up until a few hours prior to surgery, I intentionally pushed my pace until my arrhythmia kicked in (rather than avoiding going into arrhythmia as I have been doing for almost five years now). In short, my EP and I did everything we could to create a successful outcome.

It was highly uncomfortable having the medical team pacing my atrial heart rate at around 270 bpm for three hours; my heart was banging around inside so hard that even the right side of my chest punched outward from time to time. And it was not comfortable having holes pierced into each side of my groin and then having multiple catheters fed through those holes into both of my femoral veins and worked along the veins until they arrived in the correct spot in the right atrium. After the procedure, I was exhausted, and my mouth felt parched from the atropine that had been squirted into my bloodstream along with isoprenaline (synthetic adrenaline) to drive my heart rate up.

As for getting second opinions and trying again, which almost everyone I talk to suggests, I do not see the point unless I find out about a technology to do the mapping even if the arrhythmia won’t persist in the lab longer than a couple of seconds. Electric jolts and stimulant drugs while lying on a table simply don’t adequately simulate what my heart experiences while cycling, skiing, or running, and there is no way to actually do those activities during the procedure. The mapping computer times its data collection along with the patient’s respiration rate and only takes snapshots of the 3D X-ray images of the heart at the same point in each breath, chopping off the rest of the data to create a stable picture of the heart on the screen, rather than showing a wildly beating organ with catheters flopping around in it. The patient must hold still to do the mapping; I can’t imagine that the computer could follow the heart around while running on a treadmill, for instance, well enough to create a stable picture of it. And since you have catheters running up into either side of your groin, riding a stationary bicycle during the procedure is also a no-go.

While I imagine that there might be some EPs who would burn some tissue in my heart without a precise map of my arrhythmia, I’m not volunteering for that. Once muscle cells in the heart are killed, they don’t rejuvenate. I wouldn’t want to still have the arrhythmia plus a section of dead tissue in my heart.

I also understand that other doctors might come up with other diagnoses. In fact, I have sent EKG files of arrhythmia events recorded by my LINQ monitor during exercise to other EPs, and I have received a number of different diagnoses. However, I know from my own diagnosing of bike problems that people email to me, it is one thing to come up with a diagnosis and suggest a solution for somebody with whom I have no investment than it is if I am faced with the same problem on a bike in my hands belonging to a customer; my tune might change with a deeper investment in my solution being correct. Analogously, I believe that some of those doctors’s diagnoses might also change if I were to become their patient and they were to become responsible for success or failure at eliminating my arrhythmia.

My doctor is well-respected in the EP field, and he has taken the time to show me with a caliper on my EKG graphs exactly why he believes it is atrial tachycardia and not AFib or atrial flutter, conditions that other EPs told me they found on my graphs that I sent them. I like and trust my doctor, I appreciate the way he takes whatever time is necessary with me to explain what he sees, and my philosophical leaning aligns with his conservative approach, which he describes as, “Look 10 times; burn once.” Also, he is in Boulder, where I, most of my family and support structure live, which I think is important for healing, and I don’t believe that other facilities offer better technology than his EP lab at BCH.

I don’t ever want to go through that again; I have concerns about damage my heart may have sustained by going through this twice, and if I’d known what the (non) results would be, I never would have done it either time. Ever since the procedure, my heart has felt fluttery inside my chest. I imagine it’s trying to recover from being pushed so hard, and I hope it does recover at least to its pre-procedure condition. I also believe that the radiation dose I received by having two X-rays pointed at my heart for three hours this time and four hours the first time was no health tonic.

I let all of the sadness and disappointment pour out when my wife came into the recovery room afterward. I am now left wondering how to plan my life. I still will ride and ski; I love them too much to ever give them up. Maybe I’ll still go along on some of my buddy Charlie’s Scatto Bike Tours as a mechanic and just ride with the group when my heart allows it. I probably have done my last cycling gran fondo or Worldloppet mass-start cross-country ski race, both of which I have enjoyed doing all over the world. I am also going to build myself a titanium road/gravel e-bike. Davis Phinney has suggested I get an e-bike, as his allows him to ride with buddies his health condition otherwise would not, and I want the same thing. If unimaginably fast cyclists of my generation like him and Greg Lemond can ride e-bikes, there is no shame in it.

I will also throw myself more into my boyhood sports of kayaking and rafting. I have never felt an arrhythmia while whitewater kayaking or rafting or sea kayaking, no matter how hairy the rapids or high the ocean swells and winds. I hope that continues. I do have a river permit for a 19-day private trip with 16 family members and good friends through the Grand Canyon for this summer, and my fantastic orthopedic surgeon, who also happens to be a good friend and cycling buddy, just repaired my torn left rotator cuff to ensure I will once again be able to row my raft powerfully through its rapids. I still have a great life, even if I can’t ride my bike up mountains anymore. Sometimes I have to remind myself of that.

Thanks for reading.
— Lennard