SVT-AVNRT

Reconnecting with my childhood friends, Drs. Jocelyn and Danny Spoon. 

My breast cancer diagnosis this spring coincided with also being diagnosed with SVT-AVNRT. SVT-AVNRT is a heart arrhythmia that affects approximately 1% of the population. I’d never heard of it before and it’s certainly easier to refer to it by SVT-AVNRT than by its full name: Supraventricular Tachycardia; subtype: Atrioventricular Nodal Reentry Tachycardia.

The first indication I had of potentially having an arrhythmia occurred in December 2021. In early 2022 I had follow-up tests including a Holter monitor and a cardiology consultation. The Holter monitor didn’t reveal any abnormalities, and the cardiologist wrote it off saying I just had a fast heart rate.

I didn’t think much more about it until I started having symptoms again in December 2024. Soon the “episodes” as I called them were increasing in frequency and duration. I had read that heart palpitations can be a symptom of perimenopause, so I initially tried to convince myself that was all it was.

The “episodes” would strike at random and rather mundane times…while having a conversation with family and friends, at work, playing a board game, and once at a cabin with friends during a backcountry ski trip. I knew immediately when an “episode” was about to happen because I felt what I referred to as a “sense of doom” in my chest and then my heart would just take off to the races…from a normal resting heart rate of 85 to 145-195 beats per minute!

I would try to stay calm, practice deep breathing, meditate, drink water, etc. I also learned about vagal maneuvers that could be used to help reset the heart. Common vagal maneuvers include “bearing down,” putting your feet up against a wall, blowing into a syringe, or putting your face in ice or cold water. Within 10-40 minutes, the maneuvers would eventually work, and my heart rate would return to normal just as quickly as it spiked.

On April 15^th I had an episode that felt different from the others. For one, it lasted significantly longer and according to my Fitbit, my heart rate got up to 195. The vagal maneuvers were not working and most concerning to me was that my breathing started to feel a bit labored.

About an hour and a half into the episode, Dory took me to the ER. We told the woman at the intake desk that my heart was racing and in no less than 20 seconds I was having an EKG. After the initial staff viewed the EKG, I was immediately wheeled back to a room and I remember the nurse leaning against a wall, crossing her tattooed arms, looking up at the monitor and saying, “you are running a fucking marathon!”

The doctor came in shortly thereafter, asked a few questions, consulted with a cardiologist and explained that what I was experiencing was SVT-AVNRT. The quickest way to resolve the issue in the moment was to inject me with a medication called adenosine which would momentarily stop my heart, allowing it to restart and resume its normal rhythm. At that point Dory asked if she should message my family!

They got the defibrillator ready in case it should be necessary and off we went. I think I now know what it might feel like to have a stroke or heart attack. When my heart momentarily stopped everything went black and it felt as if I had a vice on the left side of my body—the pressure was intense! And then, just like that, the four of us watched my heart return to its normal rhythm on the monitor.

It all sounds a bit alarming, but SVT is considered a benign condition. The typical heart beats 60-100 beats a minute. During an SVT episode, the heart beats between 140-220 times a minute. Treatment options include daily medication like a beta blocker to slow the heart down or cardiac ablation. After consulting with an electrophysiologist, I elected to have the ablation…. the day after having bi-lateral biopsies. For someone who rarely has to go to the doctor, it was a big week!

SVT-AVNRT is caused by an extra electrical pathway in or around the AV node. The extra pathway causes the heart to beat too early. The ablation procedure is minimally invasive and was painless and easy. I was under general anesthesia while the doctor inserted a catheter through my groin, made her way to my heart, and proceeded to scar the tissue to block the irregular electrical signals. The procedure has a 95% success rate. Beginning about two weeks after the procedure, however, I started having some recurring symptoms, so I had to wear a Holter monitor for two weeks for further assessments. Those results are still pending.

The best part about the procedure (other than hopefully fixing my arrythmia!) was that I got to reconnect with two of my childhood friends, Jocelyn and Danny Spoon. Jocelyn was one of my closest friends in elementary school up until she moved to Missoula at the end of the 5^th grade. Both she and her brother, Danny, are cardiologists at the International Heart Institute in Missoula. They were not my providers, but they stopped by to visit. We had a great time reminiscing about our childhood adventures. After being out of touch for most of our adult lives, it was fun to reconnect. We exchanged phone numbers and Jocelyn ended up being one of the first people I told about my breast cancer diagnosis. She was incredibly helpful in making recommendations for my cancer care team.

I’m very grateful that the ablation took place before the cancer treatment started so I can give full attention to this next hurdle. It can take up to three months for the heart to fully heal after an ablation, so I remain hopeful that I will have a normal functioning electrical system moving forward!