In a pacemaker, what does the term "impedance" refer to?

Impedance refers to the electrical resistance to the flow of current in the context of a pacemaker. It is a crucial measure because it affects how effectively the pacemaker interacts with the heart tissue. High impedance can indicate issues such as poor lead placement or faulty connections, while low impedance may suggest good lead contact with the myocardial tissue.

In pacing systems, monitoring impedance can help healthcare providers assess the function of the pacemaker leads and the overall system. It informs them whether the leads are properly positioned and functioning as intended. This data is vital for ensuring the optimal performance of the pacemaker, thus maintaining appropriate pacing for the patient. Understanding impedance allows for timely interventions if there are significant changes that could affect the effectiveness of the pacing therapy.