Which electrode in a cardiac device is characterized as the positive electrode?

The correct answer is the anode, which is characterized as the positive electrode in a cardiac device. In electrochemical terms, the anode is where oxidation occurs, and it is the electrode that attracts electrons from the external circuit. In the context of a cardiac device, such as a pacemaker or implantable cardioverter-defibrillator, the anode facilitates the collection of positive ions that contribute to the pacing function.

In contrast, the cathode, which serves as the negative electrode, is responsible for attracting positive ions during the pacing cycle, releasing electrical signals to stimulate heart contractions. The lead is a structural component that connects the generator to the heart but is not defined by its charge. The generator itself is the power source of the device, housing the battery and circuitry that manage the delivery of electrical impulses.

Thus, the anode's role as the positive electrode is essential for the function of cardiac devices, enabling effective pacing and therapy application in patients with heart rhythm disorders.