Final answer:
The respiratory therapist should synchronize the defibrillator to the P wave on the ECG prior to a cardioversion procedure for the treatment of atrial fibrillation.
Step-by-step explanation:
Prior to a cardioversion procedure for the treatment of atrial fibrillation, the respiratory therapist should synchronize the defibrillator to the P wave on the ECG.
The P wave represents the depolarization and contraction of the atria as they pump blood into the ventricles. Synchronizing the defibrillator to the P wave ensures that the electrical shock is delivered at the appropriate time during the cardiac cycle.