I don’t really know what happened but I almost passed out the other day. I was standing and then it felt like my heart started to beat slow but when I took my pulse it was fast. My vision blacked out a bit and I got really dizzy. I don’t know why this happened but I suspect it had to do with my heart. I get frequent pain in my chest and have a heart murmur and my chest had been hurting more than normal before I almost passed out. Any ideas on what this could be? I usually only get symptoms like this when I’m having a panic attack but I didn’t feel panicked.