Which type of heart block is treated with a pacemaker?

The treatment of heart blocks often depends on the severity and the symptoms they cause. In the context of heart block, a pacemaker is typically indicated when there is a complete failure of electrical conduction, which is most commonly seen in third-degree heart block. This condition, also known as complete heart block, occurs when the electrical signals from the atria cannot reach the ventricles, leading to a dissociation between the two chambers. This can result in bradycardia and significant symptoms related to reduced cardiac output, making timely intervention critical.

A pacemaker provides a reliable source of electrical impulses to stimulate the heart, ensuring a coordinated contraction and maintaining adequate heart rate and rhythm. In contrast, first-degree heart block and Mobitz type 1 block typically do not require treatment since they often present asymptomatically and do not significantly impair cardiac function. Mobitz type 2 may sometimes require a pacemaker depending on the patient's presentation, but it does not have the same urgent need for intervention as third-degree heart block. Thus, the clear indication for a pacemaker placement is found in the complete interruption of conduction characteristic of third-degree heart block.