Recommendation 1 - Anticoagulation for at least 3 weeks before elective cardioversion (2018, updated from 2010)
We recommend that in addition to appropriate rate-control, most hemodynamically stable patients with AF or AFL for whom elective electrical or pharmacological cardioversion is planned should receive therapeutic anticoagulation for 3 weeks before cardioversion (Strong Recommendation, Moderate Quality Evidence).

Recommendation 2 - Circumstances where deferral of anticoagulation prior to cardioversion may be appropriate (2018, updated from 2010)
We suggest that pharmacological or electrical cardioversion of symptomatic AF or AFL without at least three weeks of prior therapeutic anticoagulation be reserved for patients with the following characteristics (Weak Recommendation, Low Quality Evidence):

a) patients with non-valvular AF presenting with a clear AF-onset within 12 hours in the absence of recent stroke or TIA (within 6 months)
b) patients with non-valvular AF and a CHADS2 score < 2 presenting after 12 hours but within 48 hours of AF onset

Practical tip (2018)
Non-valvular AF is defined as AF in the absence of mechanical heart valves, rheumatic mitral stenosis, or moderate to severe nonrheumatic mitral stenosis.

Recommendation 3 - The use of transesophageal echocardiography as an alternative to anticoagulation prior to cardioversion (2018, updated from 2014)
We suggest that, as an alternative to at least three weeks of therapeutic anticoagulation prior to cardioversion, transesophageal echocardiography (TEE) may be employed to exclude cardiac thrombus (Weak Recommendation, Moderate Quality Evidence).

Values and preferences (2018)
This recommendation places a high value on immediately addressing instability by attempting cardioversion, and a lower value on reducing the risk of cardioversion-associated stroke with a period of anticoagulation pre-cardioversion. Therapeutic anticoagulation therapy should be initiated as soon as possible.

Recommendation 4 - Immediate electrical cardioversion for patients who are hemodynamically unstable (2018, updated from 2014)
We recommend that immediate electrical cardioversion be considered for patients whose recent-onset AF/AFL is the direct cause of instability with hypotension, acute coronary syndrome, or pulmonary edema (Strong Recommendation, Low Quality Evidence)

Recommendation 5 - Immediate initiation of anticoagulation prior to unplanned cardioversion (2018, updated from 2010)
When a decision has been reached that a patient will be undergoing unplanned cardioversion of AF/AFL, we suggest that therapeutic anticoagulation therapy be initiated immediately (preferably before cardioversion) with either a NOAC, or with heparin followed by adjusted dose warfarin (Weak recommendation, Low Quality Evidence).

Recommendation 6 - Anticoagulation for at least 4 weeks post cardioversion (2018, updated from 2010)
We suggest that, in the absence of a strong contraindication, all patients undergoing cardioversion of AF/AFL receive at least four weeks of therapeutic anticoagulation (adjusted-dose warfarin or a NOAC) after cardioversion. (Weak recommendation, Low Quality Evidence). Thereafter, we recommend that the need for ongoing antithrombotic therapy should be based upon the risk of stroke as determined by the CCS algorithm (“CHADS-65”) (Strong Recommendation, Moderate Quality Evidence).

Values and preferences (2018)
This approach places relatively greater emphasis on the benefits of stroke prevention in comparison to the risks of bleeding with a short course of anticoagulation therapy. Although it may be possible to parse these risks based upon either patient characteristics or the duration of acute AF/AFL, the CCS AF Guidelines Committee at this point has chosen to simplify by recommending anticoagulation for one month after cardioversion for all such patients in the absence of a strong contraindication.

Practical tip (2018)
When oral anticoagulation is to be used for only a short period (less than two months) current evidence does not substantiate either an efficacy or safety advantage for use of a NOAC over adjusted dose warfarin. Nevertheless, the convenience of use of a NOAC over adjusted-dose warfarin in the peri-cardioversion period is substantial and the onset of therapeutic anticoagulation is nearly immediate with a NOAC while being delayed in the case of adjusted-dose warfarin. Accordingly, it is reasonable to use NOAC therapy in the peri-cardioversion period.