A nurse is providing teaching to a client who has atrial fibrillation and reports dizziness and palpitations. Which of the following should the nurse understand is the cause of these manifestations?

The heart's electrical transmission through the atrioventricular (AV) node is unusually slow.

The heart's electrical signals are rapid, chaotic, and irregular.

The SA node sends an electrical signal greater than 100/min.

An early electrical signal occurs before the expected sinoatrial (SA) node signal.