Because Sami's
afib was a sort of "lone atrial fibrillation" it was hard to catch. Holters are great for symptoms that happen every day. When they only happen occasionally, it's luck of the draw to catch them on a holter. So she got an event monitor.
But the thing with Sami is, she was feeling something she knew wasn't being caught on the holter or
EKG. If you had your holter and there was at least one good example of your symptoms in there, then you can rest assured it was reviewed (first by computer, then by human eyes), and determined to be harmless.
And judging from your profile picture you're pretty young - like Jodie said it usually only comes when you're older.
But don't take my word for it - have a look at this graphic:
