How does the pacing impulse travel in a bipolar lead?

In a bipolar lead, the pacing impulse travels through a defined path that includes both electrodes of the lead. This design ensures effective capture of the cardiac tissue. Specifically, the impulse originates at the tip electrode, which serves as the primary source of the electrical signal. From the tip, the impulse travels through the intervening cardiac tissue until it reaches the ring electrode. This configuration allows for more localized stimulation and reduces the potential for stimulation of surrounding tissues, compared to unipolar leads.

The bipolar lead's configuration offers advantages such as reduced risk of lead-related complications and decreased energy requirements for pacing. Understanding this pathway is crucial for comprehending how pacing systems effectively trigger heartbeats while minimizing impacts on adjacent tissues.

In essence, the journey of the pacing impulse, starting from the tip electrode and moving to the ring electrode through the tissue, is critical in achieving effective pacing and ensuring proper cardiac function.