15. We suggest that digoxin can be considered as a therapeutic option to achieve rate control in patients with AF and symptoms caused by rapid ventricular rates whose response to b-blockers and/or calcium channel blockers is inadequate, or in whom such ratecontrolling drugs are contraindicated or not tolerated (Conditional Recommendation, Moderate- Quality Evidence).

Values and preferences. Digoxin is considered a second-line agent because although some published cohort, retrospective, and subgroup studies show no harm, there are others that suggest possible harm.

Practical tip. When digoxin is used, dosing should be adjusted according to renal function and potential drug interactions. With analyses that suggested higher drug concentrations are associated with adverse outcomes, maximum trough digoxin serum concentration of 1.2 ng/mL would be prudent. When digoxin is being used to treat patients with concomitant left ventricular systolic dysfunction, its use should be dictated by the recommendations of the CCS Heart Failure Clinical Guidelines.