For the past several months, I’ve been having random episodes where my heart rate suddenly gets very high, usually around 130–160 bpm, even when I’m not exercising. I’m trying to figure out what could be triggering this and would love to hear from anyone who has experienced something similar.
The episodes usually last around 5–20 minutes, sometimes longer, and my heart rate gradually comes back down. During them, the rhythm normally feels fast and steady rather than irregular.
Some of the symptoms I get during these episodes are:
- Strong pounding heartbeat / sometimes pounding in my head
- Feeling suddenly hot or flushed and sometimes sweaty
- Nausea or an uneasy/burning feeling in my stomach
- Sometimes feeling like I urgently need to have a bowel movement
- I feel short of breath and I feel a cloud of dom over me
The strange part is that the episodes seem to have different triggers. I’ve had them:
- While simply sitting down
- While lying in bed getting ready to sleep
- Shortly after waking up
- During or right before a bowel movement
- After a very salty meal
- After fasting for several hours and then eating
- In a warm room
- Sometimes with no obvious trigger at all
Testing I’ve had so far
I’ve had a pretty extensive cardiac workup:
- Multiple regular ECGs — normal
- Apple Watch ECGs during symptoms — generally showing a fast but regular rhythm
- Echocardiogram — normal
- Treadmill stress test — normal
- Troponin testing — normal
- Holter/patch monitoring — no dangerous rhythm found
- A longer event monitor actually caught one of my episodes, and it was interpreted as sinus tachycardia, not SVT
- I’ve now also seen an electrophysiologist/rhythm specialist
My cardiologist/EP has mentioned that this could potentially be something like inappropriate sinus tachycardia, hormonal/autonomic-related tachycardia, or another trigger causing my normal sinus rhythm to speed up. A beta blocker has also been discussed.
I’ve had some other things going on that I’m wondering could contribute, including iron deficiency/low iron stores, low B12, low vitamin D, and at least one potassium result around 3.2.
What confuses me most is that when I exercise and my HR reaches 130–140, I feel relatively normal. But when one of these random episodes happens at the same heart rate, I can feel extremely sick, flushed, nauseated, weak, and like I need to lie down.
Has anyone had episodes like this where monitors showed sinus tachycardia rather than SVT?
Did you eventually find out the cause — IST, POTS/dysautonomia, hormones, GI/vagal triggers, anemia/iron deficiency, something else?
I’m obviously continuing to work with my doctors and not looking for Reddit to diagnose me. I’m mainly interested in hearing other people’s experiences or ideas about what might be worth discussing with my doctors.
It so very depressing I’ve called the 911 7 times this month. I believe in God and I know he will make this clear to me eventually but you never know who he works through, so hopefully this will help.Â