Around every 10 minutes my heartbeat starts getting very fast, it ll feel as if it stops for a second and beat once very hard, then it ll go back to it s normal rhythm. Also, I have asthma and whenever I take my inhaler, I ll hold it in for not even 5 seconds then my heart rate will almost triple, blackness literally starts quickly consuming my vision and I ll start to collapse unless I exhale. After I exhale, my vision returns kinda slowly, I ll have a bad headache until it returns and once those two are over my heart beat returns to normal. Do I have a heart condition? If so, is it potentially lethal?