As you have already been wisely told, heart palpitaitons are pretty much part and parcel of anxiety/panic states. They are, without a doubt, one of the most classic symptoms of anxiety and panic. For the vast majority of us, they are frightening but 99.9% of the time, they are totally benign and do absolutely no damage to your heart.
To ease your mind, have a complete cardio work-up and get the reassurance you need that your heart is fine and have the cardilogist talk to you, IN DEPTH, about palps. Knowing what is happenig to your heart during a palp will help you to accept these benign (and yes, scary) changes in the rhythm of your heart. Once you realize how very common they are, that most people experience them, but those of us with health or heart anxiety are hyper-vigilant to any change and we turn our full attention to them, which increases our anxiety and in turn, increased the frequency of the palps. Kind of a nast merry-go-round that you can get off of.
Check out the Heart Rhythm Forum if you want to learn about what other people live with daily and how they deal with this. I promise that you will come away from that forum feeling much better, but still recommend the cardio check-up.
At 21 it is higly unlikely there is anything organically wrong with your heart. It's anxiety.
See your doctor. He/she is the only one who can ultimately put your mind at rest.
Peace
Greenlydia
This is called palputations, where you become aware of a change in your heart beat or feel your heart skip a beat or feel a flutter in your chest. It is a normal response to extreme stress and considering you have been dignosed with panic disorder is proberly nothing to do with you having a heart disorder.
However to put your mind at rest you should nip along to your doc and maybe get a refferal to a heart specialist who can give you the once over and make you feel better. At 21yrs old i'm sure this is proberly anxiety doing it what it does best, make us feel like we have every illness and disease going.
I have experienced the same thing with my heart. Mine feels like it stops and I can't breath for a few seconds. I have had it happen before a few times but in the last month it is coming more frequently. I haven't brought it up to a doctor yet but have an appointment today but I'm pretty sure it's anxiety related. Good luck