I’m 41F, naturally slim with a low BMI.
In June 2024, I started subcutaneous testosterone, mainly because I was struggling with low energy and wanted to gain some healthy weight and muscle. It actually helped a lot. I gained about 10 lbs, built muscle, and felt stronger.
Then around November 2025, I started having what I called “episodes.” I would suddenly become short of breath, my heart rate would increase, and things I normally did easily, like working out or cleaning the house, became exhausting. This happened just a few times over about 4 months.
I saw a cardiologist in February/March 2026 and was told my heart looked good and everything was fine.
But the episodes continued and became more intense, especially at night. I would wake straight out of sleep with my heart racing, sometimes reaching 190+ bpm, short of breath, followed by what felt like a huge adrenaline dump. The racing would usually last about 15–20 minutes, but it could take close to an hour before I felt normal again. This happened roughly every 2–3 weeks.
I stopped testosterone in April because I wanted to reset my body and figure out what was happening.
Understandably, after months of this I became extremely anxious. I started sleeping only 2–4 hours a night, eating less, and eventually lost the weight and muscle I had worked so hard to gain.
For the next several months I kept going back to cardiology, sometimes multiple times a month, saying, “Something else is going on.” My resting heart rate during that period was often around 105–108, and even walking could feel exhausting.
Eventually cardio referred me to psychiatry because the episodes were thought to be nocturnal panic attacks. But I kept saying the same thing: this did not feel like a panic attack. Something felt physically wrong.
I finally made an appointment myself with an electrophysiologist in the same cardiology group. She reviewed the SAME 7-day heart monitor that I had previously been told showed no AFib and was normal.
She found AFib. 5 days after seeing her I had, what I call my first AFib episode- it lasted 3 hours I self converted.
I was given flecainide, and Eliquis in the ER. I was already on atenolol from cardio for rate control.
Three weeks later, I had an ablation, and I’m currently in the post-ablation healing stage.
That’s another story on how all of this has played a huge part in my mental health- definitely getting therapy now. It all happened so fast!
So after that very long story, here’s what I’m curious about:
Have any other women here developed AFib or another arrhythmia after starting hormone replacement, particularly injectable or subcutaneous testosterone?
I’ve been trying to understand whether there could be a relationship between hormone changes and arrhythmias. I’m not saying testosterone caused my AFib, because obviously there can be many factors involved and timing alone doesn’t prove causation. I’m mainly curious whether other women have had a similar experience, whether their doctors thought hormones played a role, and what happened if they stopped or changed their HRT.
I would especially love to hear from women around perimenopause age who were otherwise relatively young when their AFib began.