My classmate collapsed during a baseball practice a month ago and it was said that he has Ventricular Fibrilation (not sure if spelling is correct) he was sedated for a few days, and he s been awake. he has been in the hospital well over a month now. I m just curious, he can t speak yet, he has a hard time moving, and i m really worried. whats going on?

Summarized question: What causes ventricular fibrillation?