I have a condition called Supraventricular tachycardia, was diagnosed several years ago and it just causes a dramatic spike in heart rate randomly for me. Its relatively benign unless combined with other heart conditions usually. Definitely worth looking into, but I'm not sure how common it is. Otherwise pain and anxiety cause my heart rate to spike also, although not to as high of a rate usually.

I have never been diagnosed with any heart issues but as of recently this same thing has been happening to me. I also haven't gotten any results because all testing is normal, i was even hooked up to a heart monitor during my last ER trip.

I have two theories - 1. My body is reacting to the physical issues, the pain and inflammation OR 2. Its due to anxiety

One thing ive done is track my heart rate and oxygen saturation on my phone. Newer samsungs have a sensor on the back, and using the samsung health app you can get a reading and then it asks you questions like "how are you feeling." Then you can save it to keep track. Its helped me alot.

I’ve had this too; my heart rate spikes to 140s, I get lightheaded, sweaty, and my pelvic area starts to hurt, my stomach hurts, and I get the urge to go to the bathroom. I went to the ER a year ago due to this, and all labs/bloodwork, heart monitor came back normal.
I’ve had anxiety attacks for years, which have gone away now for 3 years, and this feels distinctly different to me in all the physical pain, particularly in the pelvic area. My endometriosis is in the ovary. Maybe it has to do with cyst rupture? I’ve had a cyst rupture in the past, and it feels very similar—body’s reaction to pain. Or as the other person above mentioned, inflammation.
It feels like an attack; it passes then everything more or less turns to normal.
It’s scary when it happens. I hope we can all figure out why we get it.