What is atrial fibrillation with RVR?
Atrial fibrillation is an abnormal heart rhythm originating from the upper chambers of the heart (atria). Usually the atria do not contract well in atrial fibrillation as the rate of electrical activation in atrial fibrillation is very fast, of the order of 450 to 600 times a minute. The muscles of the atria (left and right atrium) cannot contract so fast and they will just quiver or virtually stand still. The fast electrical signals are blocked while being transmitted down to the lower chambers of the heart (ventricles). Large number of signals are blocked in the atrioventricular junction by a structure known as the AV node (atrioventricular node). So the ventricles contract at varying rates. If the rate at which the ventricles contract are very fast, usually more than 120 per minute, it is known as rapid ventricular response (RVR) or fast ventricular response (FVR).
If the ventricular rate is lesser, it is known as controlled ventricular rate, which occurs usually when the person is on medications to control the ventricular rate. Sometimes the ventricular rate can also be slow. In that case it is called as atrial fibrillation with slow ventricular response / rate. This occurs when either the AV node is diseased so that it allows only few signals to pass through or when it is heavily blocked by medications.