For me, it's when my RBC and hematocrit etc get low. Anemia, essentially.

Any update on the OP?

Any meds? this can happen from asthma meds and possibly caffeine (including tea, chocolate), etc. Try deep belly breathing (google it if you aren't familiar) to relax the heart??

Probably PVC's (premature ventricular contractions)-- usually benign, but worth getting checked out.

This is what it sounds like, but definitely something you should get checked. Glad you did.

Get yer thyroid checked.

Fluctuations in caffiene intake? Much more or much less than usual?

I had an episode of tachycardia early in one of my pregnancies. I thought my heart was going to come out of my chest and it lasted for about 24 hours.

I developed heart palpitations during a very emotionally stressful time of my life. Could it be that? They went away once things got better.

PVCs. I get them a lot. Doctors have been entirely unconcerned so I don't worry about them anymore. Weird feeling, though, isn't it??

Doctor should have you wear a halter monitor for a few days to figure it out if they cant catch in on an EKG

OP here, got some blood work done so we'll see, but Dr. does not seem worried.

Hyperthyroidism?

I had this. Just diagnosed with SVT. Supra ventricular tachycardia. Not dangerous and usually does not last too long. Told it could get worse as I age. There are surgical treatments and medication but it all depends on how often and how long the episodes last. I had it go on for over an hour previously. Usually brought on by exercise. Exacerbated by stress, dehydration and caffeine. Cutting back on caffiene, drinking Gatorade, it is helping.

allergy/sinus