My heart rate will go from 95 to 170 and sometimes higher and then drop again quickly. When this happens I get dizzy and have passed out several times. I was diagnosed with SVT but haven't had any issues for over 5 years. Now all of a sudden my heart rate is always fast and the passing out has started again. I go to hospital and they just send me home because the episode is usually over by the time I get there. Is this the SVT or something different?