The rhythm in Figure 18 is
A)Wenckebach.
B)Mobitz II second-degree AV block.
C)Third-degree AV block.
D)Junctional bradycardia.

Question

The rhythm in Figure 18 is 
A)Wenckebach. 
B)Mobitz II second-degree AV block. 
C)Third-degree AV block. 
D)Junctional bradycardia.

Quizplus · Accepted Answer

The rhythm in Figure 18 is showing a complete dissociation between the atria and ventricles, with no discernible relationship between the P-waves and QRS complexes. This is characteristic of a third-degree AV block, also known as a complete heart block. In this type of block, the electrical impulses generated in the atria are unable to reach the ventricles, and so a backup pacemaker takes over, usually in the form of the AV node or a lower site in the conduction system. The ventricular rate is usually slower than the atrial rate, and there is no regular pattern to the ventricular rhythm. This is different from choices A and B, which are both forms of second-degree AV block, and choice D, which refers to a slow heart rate originating from the AV nodal region.

The Rhythm in Figure 18 Is