A rhythm described as 'Regular rhythm block' corresponds to which block type?

• A. 1st Degree Block
• B. 2nd Degree Type 2
• C. 2nd Degree Type 1
• D. 3rd Degree Block

Answer: (D)

Regular rhythm block points to a complete AV conduction failure with an independent ventricular rhythm. In a third-degree (complete) AV block, the atria fire on their own and the ventricles beat on a separate escape rhythm. This creates a steady, regular ventricular rate that is not coordinated with the atrial activity, so you see P waves and QRS complexes that have no fixed relationship. That clear dissociation and regular ventricular rhythm are what this description captures, making the third-degree block the best fit.

The other blocks don’t fit as neatly: a first-degree block delays every impulse but conducts all of them, so there isn’t a block to describe; a second-degree type I shows progressively lengthening PR intervals with occasional dropped beats and an irregular rhythm; type II has fixed PR intervals with dropped beats, leading to an irregular pattern. None of those produce the complete, regular dissociation seen in a third-degree block.