Rapid Heart Rate & Vomiting?

I was wondering why it is that some people (myself included) have a sudden and frighteningly rapid racing of the heart just before and during vomiting (due to stomach poisoning or the flu- no alcohol or drugs involved to account for an adverse drug reaction.) There's no pre-vomit running around to account for the racing heart, or even heavy breathing present. It almost feels like a heart attack in terms of the beats seemingly out of control and coming on so suddenly when you're in a sedentary position (bending over the commode). Another relative experiences this heart problem too, but she also has a heart murmur and has had bouts of unexplained tachycardia. Are these all related, or is it rare to have racing heart when throwing up? Also, is it possible to pass out from this racing heart? I think that this particular aspect of throwing up is the most unpleasant part (with the nose vomit a close 2nd), and why I dread getting sick this way vs. a cold.

I would like to give a medical explanation for this if I may. BTW, hi everyone, I'm new here, Andrew you and I have communicated privately in my other old email, I've enjoyed catching up here, I think you're doing a wonderful job!

Andrew step in and help me with these descriptions if I get something wrong:

The vagal nerve bundle that stimulates the stomach also stimulates the heart rate, blood pressure, etc. So, let's say for example if you ate something that makes you ill then it stands to reason that the heart is also going to be stimulated as well as blood pressures.

In fact, when an older person gets food poisioning it's often the rapid fluctuations in blood pressure, heart rate, etc. that does them in. This sort of stress is no tolerated well in some people who are already feeble.

Now, let's assume for a moment that you do NOT have anything stimulating the stomach such as food poisioning, etc. but you notice you have a rapid heart rate and/or palpatations whether it be a
"normal" heartbeat or an "abnormal" one, THIS alone can cause rapid onset of vomiting and diareaha because it's the body's way of converting the abnormal thing happening in the chest.

It's not uncommon for a documented SVT patient to go into a rhythm and vomit suddenly then be just fine a few moments later. So, sorting which comes first, the chicken or the egg is the key here, as well as sorting what is a relatively harmless SVT or a rhythm disorder that needs further study.