An eighty-year-old client admitted with dizziness has a monitored rate of 34. Looking at the strip, the P waves are regular and the QRS complexes are regular — but they have no relationship to each other. The P waves march through the tracing at their own pace, sometimes landing on a QRS, sometimes on a T wave, sometimes alone. Nothing links them. That absence of relationship is the entire diagnosis. In complete atrioventricular block, no impulse crosses from the atria to the ventricles. The atria beat to their own pacemaker and the ventricles beat to a backup pacemaker that has taken over below the blockage. Both chambers are working; they are simply no longer talking. What makes this dangerous is not the slow rate by itself but the dependence it creates. The client's cardiac output now rests entirely on a subsidiary pacemaker that was never designed to run the heart — one that is slower, less reliable, and capable of stopping without warning. The clinical question is therefore not only "what is the rate?" but "how trustworthy is the rhythm...