Heart fibrillations - Atrial or Ventricular?

Dear Ask The Doctor: I have congestive heart faluire and twice i felt fibrilations that self terminated after 3 seconds, could it be a transient ventricular fibrilation? or is it an atrial fibrilation? i know i had fibrilations for just 2-3 seconds but during the fibrilations there werent no contractions i just felt a fibrilation then suddenly my heart back to normal. can it still be an atrial fibrilation? or is possible to have a transient ventricular fibrilation that reverses spountaneously?

Dear Camila: In my opinion, what you have been experiencing  could be an atrial fibrillation which is rarely fatal but does require treatment as it can lead to severe discomfort, heart failure or stroke. On the other hand VF episodes cease the pumping action of the heart, leading to sudden collapse, due to the loss of blood supply to the brain and other vital parts of the body, and defibrillation needs to be carried out within minutes to prevent life threatening outcomes.