Is it possible for your heart to go into fibrillation if you exceed your maximal heart rate?

Your maximal heart rate is 220 - MINUS your age. In most human their MHR is about 200- 220 BPM. Maximal heart rate is the highest number of times per minuet that you heart could contract during maximal physical exersion. It is unlikely for your heart to go into Fibrillation at heart rates of 200 - 250 BPM. Fibrillation occurs at heart rates of 300- 600 BPM and can be causes by Heart disease Electrical shock Heart attacks Heart Arrhythmia