Final answer:
The statement is true; in atrial flutter, the normal P wave is replaced with flutter (F) waves on an ECG, indicating abnormal rapid atrial activity.
Step-by-step explanation:
The statement that in atrial flutter, the P wave is replaced with a fine F wave is true. Atrial flutter is a type of cardiac arrhythmia where the atria of the heart beat very rapidly, but in an organized pattern. In an electrocardiogram (ECG), this condition is characterized by the appearance of flutter (F) waves which replace the normal P wave seen in a typical ECG, signifying atrial depolarization. These F waves are due to the rapid reentrant circuits in the atria. Unlike the P wave, which represents atrial depolarization in a normal sinus rhythm, the F wave is sawtooth in appearance and indicates the abnormally rapid and organized electrical activity in atrial flutter.