I understand this is not what you want to hear but I recommend also going to a doctor and explain what you experience, when it happens and what you do to make it happen. He may do some basic tests such as a GTT (Glucose Tolerance Test), EKG and Stress Test. If a GTT is done request the 5 hour test, the 3 hour test may not be adequate as some people with hypoglycemia do not respond until between 3-5 hours but may have an extreme drop in that time. Also a 4 day fasting may not show any useful results if you are fit and active.
If it is a medical problem that is left untreated and shows up later uncontrolled it could cause you to be prohibited in getting/keeping a drivers license, cause a stroke or even death.
It may require medication or simply monitoring and minor changes to your diet which are easily adapted when early detection is done.
The one factor that signaled a potential medical situation was the increased heart rate. For such control to be a productive ability the heart rate should either remain constant or drop some as you go into a relaxed state of functional effectiveness. Reaching and maintaining such states take practice and depending on the person may be easy or difficult to reach. You may already have he basics just in the opposite direction.
If you want to work with it in a safe manner I would suggest getting a biofeedback monitor. With one you can better learn to control your physical responses while at the same time working on increasing your mental awareness and responses. I have seen basic ones years ago at Radio Shack for just a few dollars that were not bad or you may get one with a little more control starting around $40 and going up on price to over a hundred. Learning to do this can be very practical for anything from pain management to manipulating a polygraph. I have used such control ability in these manners. Polygraph operators get upset when they get conflicting responses to the same questions, I have had 5 tests with the same questions each with different results while in government service. I also controlled an e-meter while "researching" inside Scientology back in the early 80's.
On a positive note, if you learn to do what you do with a balance or drop in pulse and blood pressure it can be very healthy. It can help you in different areas of life be it your job, dealing with children and family (if necessary) and many stressful situations to even giving you enhanced concentration, effectiveness and stamina for sports or even sex.