The American Association for Thoracic Surgery (AATS) has issued new guidelines for the prevention of intraoperative and postoperative atrial fibrillation and the clinical management of patients with atrial fibrillation or atrial flutter. In addition, the guidelines provide direction for the management of patients with atrial fibrillation undergoing thoracic surgery, noting that these patients are at high risk for stroke, heart failure, and other complications, and that antiarrhythmic medications and perioperative anticoagulation may be challenging, making preoperative cardiac evaluation helpful in making clinical decisions for these patients. The new guidelines were drafted by cardiologists, electrophysiologists, intensivists, anesthesiologists, cardiothoracic surgeons, and clinical pharmacists, and the guideline recommendations were published in the September 23, 2014 issue of the Journal of Cardiothoracic Surgery. Dr. Gyorgy Frendl (Brigham and Women’s Hospital), chair of the AATS Guideline Development Group, said the exact cause of atrial fibrillation in thoracic surgery is not known, but there is no doubt that cardiac or pulmonary surgery significantly increases the risk of postoperative atrial fibrillation. As a result, cardiothoracic surgeons are paying close attention to atrial fibrillation, trying to explain how it occurs and finding ways to prevent or reduce it, which is no easy task. How to prevent post-surgical atrial fibrillation Frendl said in an interview with heartwire that the occurrence of atrial fibrillation after surgery increases the complexity and expense of the patient’s intensive care unit monitoring time, length of stay, and recovery. Physical therapy after lung surgery is important to get patients up and walking to regain fitness, but atrial fibrillation can delay this important treatment measure. In the new guidelines, experts recommend that all patients taking beta blockers before surgery should continue taking them after surgery to prevent the development of atrial fibrillation or atrial flutter (Class IA recommendation). Frendl says that after surgery, patients’ blood pressure can drop significantly, and some physicians are wrong to discontinue beta blockers as a result. In the immediate post-surgical period, most patients’ blood pressure is at a critical state, and if a patient’s usual blood pressure is 120 or 140 mmHg, it may drop to about 100 mmHg after surgery, and some physicians are concerned that beta blockers may lower blood pressure further. In response, the new AATS guidelines recommend reducing the beta blocker dose or extending the dosing interval, rather than discontinuing it. For patients with low serum magnesium levels or overall magnesium deficiency, intravenous magnesium supplementation may be considered to prevent postoperative atrial fibrillation (Class IIbC recommendation). However, guideline writing members indicated that digoxin or transcatheter or surgical pulmonary vein isolation should not be used to prevent atrial fibrillation or atrial flutter. In addition, diltiazem may be considered for the prevention of atrial fibrillation or atrial flutter in patients at moderate risk for perioperative/postoperative atrial fibrillation or atrial flutter (e.g., elderly, with hypertension or a previous history of atrial fibrillation) with preserved cardiac function and without preoperative beta blockers (Class IIaB recommendation). For patients undergoing pneumonectomy or esophagectomy, postoperative administration of amiodarone may be considered, but Frendl indicates that long-term high doses of amiodarone are problematic because they can lead to pulmonary fibrosis, among other things. A single-center study has shown that amiodarone is safe at low doses. Atorvastatin may be considered for prevention of atrial fibrillation in patients who have not taken statins and are at intermediate or high risk for surgery, but the evidence for recommendation is weak (Class IIbC recommendation). Surgical management of patients with atrial fibrillation In patients with atrial fibrillation who are taking either warfarin or a new oral anticoagulant for a long time, the timing of anticoagulant discontinuation as well as heparin bridging needs to depend on the patient’s stroke risk (assessed using the CHA2DS2-VASc score), and anticoagulation can be discontinued without anticoagulation bridging if the CHA2DS2-VASc score is <2. In addition to heparin, enoxaparin can also be used for short-acting bridging therapy in patients with a glomerular filtration rate >50%. But in any case, the aats guideline panel states that the time to discontinue anticoagulation should be minimized. < p=""> For the management of patients with perioperative/postoperative atrial fibrillation or atrial flutter, Frendl said it depends on the patient’s hemodynamic status. For hemodynamically stable patients, the primary target is heart rate control, with a target heart rate of less than 110 beats per minute and rhythm control as a secondary strategy. In contrast, for hemodynamically unstable patients, the treatment goal is urgent resuscitation. The new guidelines provide extensive recommendations for therapeutic agents for the pharmacologic management of patients with new perioperative/postoperative atrial fibrillation or atrial flutter, as well as recommendations for DC resuscitation in stable patients. Overall, the occurrence of perioperative or postoperative AF/atrial flutter depends on the type of surgery and the characteristics of the patient. For example, the risk of atrial fibrillation due to fiberoptic bronchoscopy, which is a minor procedure, is low (less than 5%), whereas the risk of perioperative/postoperative atrial fibrillation and atrial flutter due to major procedures such as lung transplantation and lobectomy is high (greater than 15%). As for patient characteristics, having hypertension, heart failure, a history of prior heart attack, obstructive sleep apnea, hyperthyroidism, left ventricular hypertrophy/increased left ventricular wall thickness, valvular heart disease, and smoking, obesity, and alcohol abuse increased the risk of peri/postoperative atrial fibrillation or atrial flutter. Finally, Frendl said perioperative/postoperative AF differs from other causes of AF in that post-surgical AF tends to resolve after 6-12 weeks, and many patients can discontinue treatment with postoperative AF medications as they heal further and as they recover from surgery.