Which lead fixation type involves tines?

The lead fixation type that involves tines is active fixation leads. These leads are designed with small tines that extend from the lead tip after the lead is inserted into the heart. The tines grip the cardiac tissue, providing a more secure anchor compared to passive fixation leads. This active fixation mechanism allows for better stability of the lead in situations where cardiac movement or activity may otherwise dislodge a passive fixation lead, which typically relies on forming a friction fit with the heart wall.

While passive fixation leads contain smooth surfaces that rely on the surrounding tissue to keep them in place, they do not incorporate tines for anchoring. Epicardial leads are a different category altogether, typically used in less common scenarios, such as during surgical procedures, and they are directly attached to the heart's surface. Transcutaneous leads are temporarily placed outside the body and are typically used for pacing in emergency situations rather than for long-term implantation. Thus, active fixation leads, with their tined design that offers superior anchoring, are the correct answer.