Introduction and definitions of AF

Post-operative atrial fibrillation (AF) is a common complication after cardiac and thoracic surgery with 20— 40% of patients suffering from this complication. AF increases the risk of mortality and morbidity from stroke, heart failure, myocardial infarction, thromboembolism, bleeding from anticoagulation and hospital readmission [1—4]. Patients who suffer AF post-operatively also have greater length of stay and, from the patient’s perspective, the episode is usually symptomatic with palpitations, nausea and malaise. In addition, these patients require more resources, including monitoring, higher dependency care and increased nursing
support. Thus, optimal preventive and treatment strategies are of paramount importance to reduce the impact of this common cardiac arrhythmia.
The aim of this guideline is to summarise the evidence in support of a variety of prophylactic and therapeutic regimens for the management of AF and to provide a comprehensive strategy to minimise the impact of this complication for patients undergoing cardiothoracic surgery.

 

DEFINITIONS OF AF

1. AF is a supraventricular arrhythmia characterized byuncoordinated atrial activation with consequent deterioration of atrial mechanical function. On the electrocardiogram (ECG), AF is manifested by the replacement of consistent p waves by rapid oscillations or fibrillatory waves that vary in size, shape and timing, associated with an irregular, frequently rapid ventricular response when atrioventricular (AV) conduction is intact.
2. Fast AF is defined as AF where the ventricular response rate is over 100 bpm.
3. Atrial flutter is a more organized arrhythmia than AF and is characterized by a saw-tooth pattern of regular atrial activation called flutter waves on the ECG, particularly visible in leads II, III and a VF, without an isoelectric baseline between deflections.

These statements are in agreement with the American Heart Association (AHA) guidelines on AF published in JACC 2001 [7].