Where are the anode and cathode located on a unipolar lead?

The correct response outlines the configuration of a unipolar lead, which typically consists of a cathode located at the tip of the lead, positioned close to the cardiac tissue, and an anode that rests within the pacemaker itself. This design allows for effective pacing and sensing by utilizing the heart tissue as part of the circuit for electrical stimulation.

In a unipolar pacing system, the lead generates an electrical impulse using the tip as the negative electrode (cathode), which is directly in contact with the myocardial tissue, allowing for effective stimulation of the heart muscle. The pacemaker acts as the positive electrode (anode), completing the circuit through the body to facilitate proper pacing functions. This setup minimizes issues related to sensing and pacing thresholds, as the closer the cathode is to the cardiac tissue, the better the ability to capture the myocardium.

Understanding this configuration is crucial for proper pacing system implementation and troubleshooting, as it directly affects the lead's performance and the efficiency of the pacing therapy.