Atrial fibrillation occurs when action potentials fire very rapidly within the pulmonary veins or atrium in a chaotic manner. The result is a very fast atrial rate — about 400 to 600 beats per ...

Just as in atrial fibrillation, not all of the P waves are able to conduct through the atrioventricular node, and thus the ventricular rate will not be as fast as the atrial rate. Typically ...