This hits close to home for me.
When I was in college, I was diagnosed with a similar condition - superventricular tachycardia (SVT). Joey Harrington was diagnosed with the same thing a couple years later, actually -
http://www.cbssports.com/nfl/story/6032297
I had two episodes, once over winter break at home and a second time four months later on campus, both resulting in trips to the ER. That summer, I went to the Cleveland Clinic for the ablation procedure mentioned in that article about Kretzer. Thankfully, I've been in the clear since.
I hope Kretzer is OK. I don't blame him at all for being freaked out after it happened to him. Scary stuff, indeed.