Hello, I've just found this forum for the first time and this is the very first I've heard of POTS. I was diagnosed with NCS a little over a year ago when I passed out during the tilt table test. Tilting upright for 30 minutes did not induce symptoms so they injected a drug and within 30 seconds of being tilted upright again, I passed out. My cardiologist diagnosed a heart arythmia and I have been taking Norpace since that time with relatively good success until recently. After reading about POTS, I'm wondering if I have that instead. I hope someone who has had similar symptoms will respond. I am female, 50 years old, and starting having symptoms at age 48. I started to have lightheaded sensations, rapid heartbeat and shortness of breath from just walking or exerting any mild form of physical activity (like standing still and using my arms to clean windows). Within seconds, if I didn't sit down, my vision would start to go black, kind of like the old black and white televisions starting to go black around the outside range of vision, closing into a little white dot in the center. Sitting down always made the symptoms go away. But they would often return upon standing and moving again. I would go for days and have no episodes and then have several days in a row with frequent episodes. These episodes had nothing to do with stress, anxiety or fear - they would occur during normal daily activity like walking my dogs. At first the only pattern I noticed was they seemed to occur most often after a meal. I noticed on weekends if I walked before breakfast, no symptoms - wait till after breakfast, and I would have to sit down several times during the walk. And what I ate did not seem to matter, it could be some fruit and juice or a full eggs and bacon breakfast - same results. My cardiologist said he could find no link between my condition and eating. But another frequent time for episodes was when walking back into work from the parking lot after lunch. I have never passed out completely, just felt sure I was going to. Since I have been taking Norpace, as long as I remembered to take my 2 doses a day about 12 hours apart, I remained symptom free, until last week. It was 2 hours till time for my second dose and I had the worst episode EVER, I really thought I was having a heart attack. My husband and I were walking around some new property with an excavating contractor and we walked up a hill (not very steep) about 50-75 yards. The lightheaded sensation started and my heart felt like it was going to beat out of my chest, I walked to the truck, sat down in the seat and the symptoms didn't get better, they got worse. My hearing started to fade, my vision started to go and I felt a wave of nausea and stomach cramping. My husband drove me home (about a 3 minute trip) and helped me into the house. I was amazed I didn't pass out on the ride home. It took about 5 minutes after coming into the airconditioned house and sitting down for the symptoms to start to subside. Since that day, I have had to start taking the second dose of Norpace six hours earlier than before, because after about 8 hours, the morning dose is no longer working and I start to have mild symptoms. My cardiologist moved and I had to see one of his associates this week. She was a total dud, told me to cut my blood pressure medication in half and come back in a month. Now I don't think you have to be a rocket scientist to understand that if moving my Norpace ahead six hours keeps the symptoms from happening, it's not the BP medicine that's causing a problem. I have appointment in Sept. with new cardiologist, hope he's a good one. To complicate this whole mess, I had renal artery angioplasty twice last year because of a disorder called fibro muscular dysplasia which causes a web of fibers to grow across the path of blood flow in the arteries that feed the kidneys. The side effect of renal blockage is high blood pressure. Both times, the blockages came back. I'm being treated at Duke University for this where they are waiting on the medicated stents to be available for renal angioplasty (hopefully within the next year or two). So, I have to take medication for high blood pressure. I have been very healthly my whole life and I'm getting really frustrated with the lack of ability to do simply exercise or chores without feeling like I'm going to pass out. Sorry for the lengthy message - I hope other with similar symptoms will respond. Thank-you - I'm really glad I found this forum! Sharon in Bedford, VA