A nurse is reviewing a client's cardiac rhythm strips and notes a constant P-R interval of 0.35 seconds. Which of the following dysrhythmias is the client displaying?

A. Premature atrial complexes. These are early electrical impulses originating in the atria that cause premature heartbeats, but they do not consistently lengthen the P-R interval. The P-R interval usually remains within normal limits unless another condition is present. B. First-degree atrioventricular (AV) block. A constant P-R interval longer than 0.20 seconds (normal range: 0.12–0.20 seconds) is characteristic of a first-degree AV block. A P-R interval of 0.35 seconds indicates a prolonged conduction delay through the AV node, consistent with this dysrhythmia. C. Complete heart block. In complete (third-degree) heart block, there is no consistent relationship between P waves and QRS complexes, and the P-R interval is not constant. This is not consistent with a stable, prolonged P-R interval. D. Atrial fibrillation. Atrial fibrillation is marked by irregularly irregular rhythm and absent, unidentifiable P waves, not a consistent P-R interval. The atria are quivering, not contracting in a coordinated way.