What type of heart block is indicated by atrial and ventricular rates that are separate?

The indication of separate atrial and ventricular rates is characteristic of third-degree AV block, also known as complete heart block. In this condition, there is a complete dissociation between atrial and ventricular activity. The atria and ventricles beat independently of one another because the electrical signals originating from the atria (the sinoatrial node) do not reach the ventricles (the atrioventricular node or below). This results in independent rates: the atrial rate may be determined by the sinus node, while the ventricular rate is determined by a lower pacemaker site within the heart, which is often slower.

In contrast, other types of heart block, such as first-degree and second-degree blocks (both Mobitz I and II), typically show a relationship between atrial and ventricular rhythms. In first-degree AV block, all atrial impulses are conducted to the ventricles but with a delay, maintaining a 1:1 relationship. In Mobitz I, the block is progressive, and there's a pattern of dropping every second beat, but atrial activity still influences ventricular response. Mobitz II may have some dropped beats but can still retain a more consistent relationship. In these cases, atrial and ventricular rates are not completely dissociated, which