What is a typical clinical effect of oversensing in a patient with a pacemaker?

Oversensing occurs when a pacemaker incorrectly interprets non-cardiac signals as potential electrical activity of the heart, which can result in the device withholding pacing when it's actually needed. This can lead to an insufficient heart rate and, consequently, inadequate cardiac output. The heart may not beat as frequently as required to meet the body's demands, particularly during activity or stress, resulting in symptoms associated with low cardiac output such as fatigue, dizziness, or syncope.

The other options describe effects that are not directly tied to oversensing. For instance, frequent syncopal episodes, heart palpitations, and continuous pacing may relate to other types of pacing issues, such as undersensing or inappropriate pacing, but they do not specifically reflect the consequence of oversensing. An understanding of how oversensing impacts the pacing system is crucial for managing patients effectively and recognizing symptoms that may arise from this phenomenon.