Question: what is atrial fibrillation and ventricular fibrillation?
Answer: Atrial fibrillation occurs in the heart's upper two chambers, also known as the atria. Ventricular fibrillation occurs in the heart's lower two chambers, known as the ventricles. If an irregular heartbeat (arrhythmia) occurs in the atria, the word “atrial” will precede the type of arrhythmia.