Girlfriend's heart issue(s?)

Today my girlfriend had a doctor’s appointment for some pains she’s been having recently. She hasn’t informed me of any of these pains until just now. So I go through my day not really worrying because I assumed it was merely a checkup seeing as she has a plethora of other health issues and has quite a few doctors she sees regularly, Marfans being one of the more predominant issues.

Anyway; I got hit with a ****ing bomb when I return home and I’m having trouble not letting my mind wander to the worst scenarios. What’s just intensifying my pain is that we’re long distance now so I can’t be there for her and just hold onto her and all that other sappy stuff that I wish I could do.
She summarized what the doctor’s said as; “it’s when the bottom chamber of the heart will randomly beat causing the top part of the chamber to fill with more blood than usual—Which is why I feel like I’m having a heart attack and the wind knocked out of me. They also bust a vein during the blood work today though and it’s still killing me.” She then went offline to take a nap and so here I am pretty much crying because I’m so scared.

What can I do for her? Going to see her is pretty much out of the question unless it intensifies as it’s quite a distance, very expensive and I’d miss a lot of school.
Does anyone know anything about what she has?
Additionally; how can I stop worrying? I know it’s not going to do any good but I just can’t help it. I want to man up. :(

She couldn’t remember exactly what the doctors called it (which may or may not be a blessing for me :x) but she said she’s going back this weekend for further blood work and examination.