What could happen to the pacing system if impedance shows a substantial increase?

When there is a substantial increase in impedance within a pacing system, it suggests that the electrical pathway between the pacing lead and the myocardial tissue may be compromised. This increase in impedance can indicate issues such as lead displacement, insulation failure, or changes in the electrode-tissue interface, which may lead to diminished pacing effectiveness and potential lead dysfunction.

Lead dysfunction can result in the inability of the pacemaker to effectively stimulate the heart, leading to suboptimal pacing or even the absence of pacing, which can compromise patient safety. Monitoring lead impedance is crucial in identifying these changes early and ensuring that the pacing system functions correctly to maintain effective cardiac rhythm.

In contrast, the other choices imply positive outcomes that do not correlate with an increase in impedance. For instance, increased efficiency and enhanced output are not characteristics associated with rising impedance levels; rather, these outcomes suggest optimal performance of the pacing system. Better signal quality would also not correspond to increased impedance; instead, it could signify issues that need to be addressed to avoid potential malfunction.