What are the different types of pacing leads?

The correct choice is based on the classification of pacing leads used in cardiac pacing systems. There are several types of pacing leads that are commonly utilized, and this answer includes the primary categories accurately.

Transvenous leads are inserted through the venous system, typically through a central vein into the heart chambers, allowing for direct pacing of the heart in a reliable manner. Epicardial leads are placed directly on the surface of the heart, often used during open-heart surgeries, providing another effective method of pacing. Additionally, lead insulators, while not a pacing lead themselves, are crucial components that protect the pacing conductors and prevent any unwanted conduction or interference, making them relevant in the context of pacing systems.

This thorough inclusion of transvenous leads, epicardial leads, and lead insulators effectively represents the comprehensive array of pacing lead types used in modern clinical practice, affirming the correctness of this answer.