Which term describes the electrical activity across the heart during depolarization and repolarization?

• A. SA node action potential
• B. Cardiac action potential
• C. Myocardial action potential
• D. Ventricular action potential

Answer: (B)

Electrical activity across the heart during depolarization and repolarization is captured by the cardiac action potential. This term describes the sequence of electrical changes that occur in heart muscle cells as they fast-depolarize, briefly plateau, and then repolarize to restore resting excitability. It encompasses the electrical behavior of the entire myocardium, including atrial and ventricular muscle and the specialized conduction pathways.

Different tissues in the heart have their own specific action potentials, which is why terms like the SA node action potential (pacemaker tissue), ventricular action potential (ventricular myocardium), or myocardial action potential (action potentials in heart muscle cells) can be used. However, the broad and inclusive term that best describes the overall electrical activity of the heart during depolarization and repolarization is the cardiac action potential.