Hi. I am currently undergoing testing for tachycardia. Have had the stress done. No results yet but at a walking speed on the third incline, bpm went to 156. That was on Friday. I frequently have tachycardia. Usually around 115-125 at rest. Originally diagnosed as POTS but that does not seem to be it. Yesterday, I got up, walked about 6 feet, and got dizzy. The next thing I remember is my tongue feeling numb and tingling. I asked my boyfriend what has happened. He said I stumbled. Braced against the wall and then told him of my tongue. I apparently only lasted a few seconds but was extremely scary nonetheless. Usually I only get dizzy but thats it. Afterward, I had a headache and went to sleep right away for about an hour and a half. The headached was slight until this afternoon when it finally went away. Back to cardiologist tomorrow, but hoping to get some reassurance tonight.