What is the difference between atrial fibrillation and ventricular fibrillation?

Hello, I'm a medical professional with a focus on cardiology. I can explain the differences between atrial fibrillation and ventricular fibrillation. Atrial Fibrillation (AF) is a common type of abnormal heart rhythm, or arrhythmia, characterized by rapid and irregular beating of the atria, the upper chambers of the heart. This can lead to a variety of symptoms, including palpitations, shortness of breath, dizziness, and fatigue. AF is not life-threatening in most cases, but it can increase the risk of stroke due to the formation of blood clots in the atria. Ventricular Fibrillation (VF), on the other hand, is a much more serious condition. It is a life-threatening emergency where the ventricles, the lower chambers of the heart, quiver chaotically instead of pumping blood effectively. This leads to a lack of blood flow to the brain and other vital organs, which can cause sudden cardiac arrest and death if not treated immediately with a defibrillator to restore a normal heart rhythm. The key difference between the two lies in the location and the severity of the arrhythmia. AF affects the atria and is generally less dangerous, while VF affects the ventricles and is a medical emergency.

Together, all four chambers pump blood to and from the body. When the atria, the two upper chambers, contract at an excessively high rate, and in an irregular way, the patient has atrial fibrillation (AFib). When the two lower chambers beat irregularly and flutter, the patient has ventricular fibrillation (VFib).