That's the answer to your description's question: before or on the 51st ball drawn. But since your heading asks a slightly different question, I'll also answer your heading's question, which is just before 51 balls.
Looking for the definition of AFIS? Find out what is the full meaning of AFIS on Abbreviations.com! 'Automated Fingerprint Identification System' is one option -- get in to view more @ The Web's largest and most authoritative acronyms and abbreviations resource.
Atrial fibrillation facts. Atrial fibrillation (AFib) is an irregular heartbeat (arrhythmia) often, but not always, resulting in a fast heart beat (greater than 100 bpm) at rest. many others that result in an abnormal electrical impulse that makes the atrial contractions of the heart irregular, disorganized and commonly, very rapid.