Which of the following statements is true regarding current in a pacing system?

In a pacing system, the current is indeed programmable, which means that healthcare providers can adjust the output of the pacemaker to optimize the pacing for individual patients. This programmability allows clinicians to tailor the pacing settings to ensure effective cardiac stimulation while minimizing potential complications, such as oversensing or undersensing. The ability to program current is crucial for achieving the desired pacing threshold and maximizing the patient's comfort and device performance.

The other statements do not accurately describe the nature of current in a pacing system. The surface area of the lead does not determine current; rather, current is influenced by other factors including lead impedance and the voltage set by the device. While current can be inferred from measurements of voltage and impedance, it is not a directly measurable value in the same way that voltage is. Additionally, current is not represented by voltage; instead, voltage and current are related through the concept of resistance within the pacing system, as defined by Ohm's Law.