What describes a condition of AV conduction disturbance with intermittent impulses between the atria and ventricles?

• A. 1st degree AV block
• B. 2nd degree AV block
• C. 3rd degree AV block
• D. Bundle branch block

Answer: (B)

The condition of intermittent impulses between the atria and ventricles is characteristic of second-degree atrioventricular (AV) block. In this scenario, some electrical impulses from the atria fail to reach the ventricles, leading to missed beats. This block occurs in two types: Type I (Wenckebach) and Type II, with the former typically showing a gradual lengthening of the PR interval before a dropped QRS complex, while the latter has more consistent PR intervals with sporadic dropped beats.

First-degree AV block involves a delay in conduction with every impulse from the atria reaching the ventricles, thus not demonstrating intermittent missed impulses. Third-degree AV block, also known as complete heart block, is characterized by a total lack of conduction between the atria and ventricles, resulting in them beating independently, which does not match the criteria of intermittent conduction. Bundle branch block pertains to a delay in conduction within the ventricles themselves rather than an AV conduction disturbance. Therefore, the correct interpretation aligns with the definition of second-degree AV block, where there are indeed intermittent impulses between the atria and ventricles.