Which type of Second Degree AV Heart Block is identified by dropping QRS complexes after prolonged PR intervals?

Which type of Second Degree AV Heart Block is identified by dropping QRS complexes after prolonged PR intervals?

• A. Type One (Wenkebach)
• B. Type Two (Mobitz 2)
• C. Complete Heart Block
• D. Advanced AV Block

Answer: (A)

The correct answer is Type One (Wenckebach). This type of Second Degree AV Heart Block is characterized by a progressive prolongation of the PR interval with subsequent non-conduction of a QRS complex. The pattern typically shows a series of beats where the PR interval gradually lengthens until a QRS complex is dropped, creating a rhythmic pattern of the heart rate. After the dropped beat, the cycle repeats. This phenomenon is often described as "grouped beating," which is a hallmark of Wenckebach. In contrast, Type Two (Mobitz Type 2) does not involve the progressive prolongation of the PR interval. In this type, the PR interval remains constant, but there are sudden drops of QRS complexes. The presence of a constant PR interval before dropped beats differentiates it from Type One. Complete Heart Block refers to a condition where there is no communication between the atria and ventricles, which does not match the criteria for either type of second-degree block. Advanced AV Block is a vague term that does not specifically refer to the identifiable patterns seen in Type One or Type Two blocks. Thus, the signature pattern of prolonged PR intervals leading to dropped QRS complexes uniquely identifies Type One (Wenckebach

The correct answer is Type One (Wenckebach). This type of Second Degree AV Heart Block is characterized by a progressive prolongation of the PR interval with subsequent non-conduction of a QRS complex. The pattern typically shows a series of beats where the PR interval gradually lengthens until a QRS complex is dropped, creating a rhythmic pattern of the heart rate. After the dropped beat, the cycle repeats. This phenomenon is often described as "grouped beating," which is a hallmark of Wenckebach.

In contrast, Type Two (Mobitz Type 2) does not involve the progressive prolongation of the PR interval. In this type, the PR interval remains constant, but there are sudden drops of QRS complexes. The presence of a constant PR interval before dropped beats differentiates it from Type One. Complete Heart Block refers to a condition where there is no communication between the atria and ventricles, which does not match the criteria for either type of second-degree block. Advanced AV Block is a vague term that does not specifically refer to the identifiable patterns seen in Type One or Type Two blocks. Thus, the signature pattern of prolonged PR intervals leading to dropped QRS complexes uniquely identifies Type One (Wenckebach