What would you expect to happen if a lead was fractured?

When a pacing lead fractures, it disrupts the normal electrical connection between the pacemaker and the heart. This disruption generally leads to an increase in impedance. Impedance is a measure of how much the lead resists the flow of electrical current. When the lead is fractured, it can behave less effectively, causing a higher resistance.

As the impedance increases, the current delivered by the pacemaker would likely decrease as well. This relationship can be explained by Ohm's Law, which states that current is inversely proportional to resistance in a circuit for a constant voltage. Therefore, if the voltage from the pacemaker remains constant and the impedance (resistance) increases due to the lead fracture, the resultant current must decrease.

This outcome aligns well with the expected behavior of electrical circuits where interruptions or failures in the components lead to changes in impedance and current flow.