How does the PR interval behave in a 2nd Degree AV Block Type II?

In a Second Degree AV Block Type II, the PR interval is consistently long but remains constant for the conducted beats that do occur. This characteristic distinguishes it from other types of heart blocks. In this block, there is an impairment in the AV node's ability to conduct some impulses from the atria to the ventricles, leading to dropped beats; however, when conduction does happen, the PR interval does not vary. It is important to recognize that while the PR interval itself is consistently prolonged, the relationship between atrial and ventricular activity is disrupted by the presence of non-conducted P waves, elucidating the nature of the block. This consistent length of the PR interval helps healthcare professionals identify the specific type of block when interpreting an ECG.