Anxiety and panic can manifest itself in many ways in my experience with it. My original experience with it came from my concerns about my heart health. When I was going through this I felt every little pain, twinge, palpatation, twitch...you name it, I noticed it. I believe we tend to become so focused in on what our percieved problem is, we will misinterpret every little feeling or symptom that we believe is related to what is bothering us. I noticed muscle twitches all over my body during this time...probably from stress but I probably also experienced these before I worried...I just didn't pay attention to it. The 'flip flop' and fluttering experience is quite common in my experience with anxiety. We become so over-sensitized that we notice EVERYTHING in my opinion. Do you have a good working relationship with your psychiatrist or do you just use him to manage your medication? I only ask this, because from personal experience, I had a great psychiatrist that managed medication issues, but I also simultaneously saw a psychologist that talked me through my experiences with panic/anxiety and gave me the knowledge to confront it.
PVCs and other benign cardiac symptoms, like palpitations are totally normal with anxiety. IF indeed that's what's going on, it is absolutely nothing to worry about.
PVCs are not always easy to diagnose as they occur so randomnly, without any kind of regularity. A standard EKG will most likely not catch it unless you happen to have one while you're hooked up. I've experienced them plenty (I have a heart murmur) and they are a scary sensation. Any sensation dealing with the heart is worrisome to us. It look me a while before I could shrug them off...and my anxiety was pretty much under control when I first erxperienced it.
If you continue to experience symptoms, you could always ask for a referral to a cardiologist, who could probably easily reassure you with a simple exam, and maybe a test or two. A holter monitor is a heart monitor, like an EKG, that you wear for 24+ hours...that's usually how something like PVCs are discovered. Most liklely, none of this is necessary, but at least you know there are some options if you need some more reassurance.
Obviously, you need to keep working at addressing that anxiety. It takes time to really get it to a manageable level. Hang in there buddy!