Which common postoperative dysrhythmia should the nurse monitor for in a patient who has undergone open chest surgery for coronary artery bypass grafting?

Rationale: A. Second degree heart block is incorrect because this type of heart block is less common after coronary artery bypass grafting (CABG). While conduction disturbances can occur, they are not the most frequent dysrhythmias in the postoperative period. B. Atrial fibrillation or flutter is correct because AF or atrial flutter is the most common postoperative dysrhythmia after open-heart surgery, particularly CABG. Factors such as atrial inflammation, electrolyte imbalances, increased sympathetic activity, and fluid shifts contribute to the development of atrial arrhythmias. These can occur within the first few days postoperatively and require monitoring due to the risk of hemodynamic instability and thromboembolism. C. Premature junctional contractions are incorrect because these are less frequent and generally less clinically significant in the postoperative CABG population. They may occur but do not represent the most common dysrhythmia. D. Ventricular ectopy is incorrect because although PVCs or other ventricular arrhythmias may appear after surgery, they are not as common as atrial fibrillation or flutter. Ventricular arrhythmias are more concerning if sustained but occur less frequently post-CABG.