What is a key feature of a 2nd Degree AV Block Type 2?

A key feature of a 2nd Degree AV Block Type 2, often termed Mobitz Type II, is the presence of more P waves than QRS complexes. This type of block is characterized by a consistent pattern of P waves that are not all followed by QRS complexes, leading to a scenario where you can have multiple P waves for each QRS complex, or at times, QRS complexes may not appear for certain P waves. This pattern results from a failure of some of the impulses from the atria (P waves) to be conducted to the ventricles (QRS complexes).

In contrast to other forms of AV blocks, Mobitz Type II typically maintains a regular rhythm with P waves occurring at consistent intervals, which can help distinguish it from other types of heart block where the relationship between P waves and QRS complexes may be more variable or chaotic. In clinical practice, recognizing this pattern is crucial for diagnosing and managing patients with heart conduction issues.