Sorry to hear.
I was diagnosed with PVC's as well. I was given an EKG/Heart holster monitor and a stress test. Results were PVC but my heart was in great condition. I only ever noticed the PVC's during withdrawal but the doctors completely ignored the idea of it being benzo related.
Benzo's aside I suffered from Panic Disorder for years and heart attack was one of my main concerns. No matter how much I'd try to convince my self that my heart was fine I could never shake it. This being said I discovered a way to control the thoughts/fear. I decided to educate my self in detail to what a heart attack truly is and how and why it happens. After actually understanding what it's all about it was clear as day to me that there is no reason for my body to produce such a scenario. In my case, I'm not overweight, I don't smoke, and I don't live on garbage food. My only issue is prescription drugs. Here is a video to get you started: (warning it may make you anxious at first but educational)
http://www.youtube.com/watch?v=JwlFcP24nHQI'd also suggest learning skills to relax/control anxiety/breathing and negative thoughts. These skills need to be practiced daily with no excuses. I'll admit, they are annoying and seem useless but it works

Take care,
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