The patient has undergone open chest surgery for coronary artery bypass grafting. One of the nurse's responsibilities is to monitor the patient for which common postoperative dysrhythmia?"

A. Premature junctional contractions are incorrect because while they can occur postoperatively, they are not the most common dysrhythmia following coronary artery bypass grafting (CABG). These are usually transient and less clinically significant. B. Ventricular ectopy is incorrect as isolated premature ventricular contractions may appear after surgery, but they are not the most frequently encountered dysrhythmia in this patient population. Ventricular arrhythmias can be serious, but they are less common than atrial arrhythmias post-CABG. C. Second degree heart block is incorrect because this type of conduction disturbance is less common after CABG. It may occur in patients with preexisting conduction system disease but is not the usual postoperative dysrhythmia. D. Atrial fibrillation or flutter is correct because these are the most common dysrhythmias following CABG, occurring in up to 30–40% of patients. The atrial tissue is often irritated by surgical manipulation, inflammation, and electrolyte shifts, making the patient prone to atrial arrhythmias. Monitoring for these dysrhythmias is crucial as they can increase the risk of thromboembolism, hemodynamic instability, and prolonged hospitalization. Management may include rate control, rhythm control, anticoagulation, and addressing reversible causes such as electrolyte imbalances.