No I haven't but a bit of background might put your mind at ease. The heart is a pump. It pumps blood around the body in a double circulatory system. One path send blood top the lungs and back. It is then oxygenate. The other half of the heart then pumps the oxygenated blood to the rest of the body where the oxygen is used by the muscles.
If your heart beat is fast, it could be that the heart is pumping blood too quickly. Is your breathing fast and shallow - i.e. are you panting like you are out of breath? It could be that the blood is not carrying enough oxygen. This is what typically causes people to faint. Soldiers fainting on parade do not faint because of a high heart beat. They faint becausenot enough oxygen is getting to the muscles.
Ideal situation: a combination of lower heart beat and high oxygen uptake. Medical tests can be carried out to determine the oxygen uptake (treadmill/breathing apparatus and heart beat monitor - as see in the movies - e.g. The Santa Clause. )
It's easy enough to identify the problem. 9I'm not a doctor so I don't know if there are other causes, but what I have described is common enough and can be remedied with exercise and it doesn't have to be too stressful - just consistent - and don't expect results over night.. (history - minor heart attack in my early 40's. Then I started exercising again - Lock Ness Marathon 2011 and 2012, now training again. Heart beat right down - resting BPM 57, Blood pressure greatly reduced, but exercise has helped reduce the meds by 50% - most of it attributed to walking.
one other possibility - your readings dropped dramatically - very good but was this a contributing factor (just asking) Another cause of fainting can be done to lack of energy
