Patient Care Technician (PCT) AAH Practice Exam

What typically happens to P waves in a 2nd-degree block type 2?

1. P waves are always conducted

2. Some P waves are non-conducted

3. All P waves are non-conducted

4. P waves are conducted with variable PR intervals

The correct answer is: Some P waves are non-conducted

In a second-degree heart block type 2, also known as Mobitz type 2, the key characteristic is that there is a regular conduction pattern for the P waves, but not all P waves are followed by QRS complexes. In this type of block, some P waves are indeed non-conducted, meaning that there are instances where the electrical impulse does not reach the ventricles, and consequently, you do not see a QRS complex following those P waves. This distinction is important as it helps to identify the nature of the block. In Mobitz type 2, P waves occur at a regular interval, but the occurrence of non-conducted P waves indicates that not every atrial contraction is translated into a ventricular response. This can be particularly significant in assessing the patient's cardiac status, as it indicates a higher likelihood of progressing to a complete heart block compared to Mobitz type 1, where the pattern is more variable and typically less concerning. The other options describe different scenarios that do not accurately reflect the specific conduction pattern seen in second-degree block type 2. For instance, stating that all P waves are conducted would misrepresent the block's characteristic of non-conduction for some P waves, and mentioning variable PR intervals is indicative