Why do I have rapid heart rate??

I’m 17 and I’ve been to a cardiologist. He said my heart sounded normal but had a innocent heart murmur. They did ekg, echo, and a 48 hour Holter monitor(but didn’t really have symptoms during this) He said I have anxiety and tachycardia. I do have anxiety and suffer from panic attacks almost everyday. But lately... show more I’m 17 and I’ve been to a cardiologist. He said my heart sounded normal but had a innocent heart murmur. They did ekg, echo, and a 48 hour Holter monitor(but didn’t really have symptoms during this) He said I have anxiety and tachycardia. I do have anxiety and suffer from panic attacks almost everyday. But lately when I wake up and even when I’m still in bed my heart starts beating very fast. and when I get out of bed it’s in the 190 zone and this doesn’t seem normal. This lasts for a few minutes and starts slowing down a bit. I also few very short of breath and just horrible when this happens. Do you think the cardiologist is missing something???
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