Society Guidelines The 2014 Atrial Fibrillation Guidelines Companion: A Practical Approach to the Use of the Canadian Cardiovascular Society Guidelines Laurent Macle, MD, a John A. Cairns, MD, b Jason G. Andrade, MD, b L. Brent Mitchell, MD, c Stanley Nattel, MD, a and Atul Verma, MD; d on behalf of the CCS Atrial Fibrillation Guidelines Committee e a Montreal Heart Institute and Department of Medicine, Universit  e de Montr  eal, Montreal, Qu ebec, Canada b University of British Columbia, Vancouver, British Columbia, Canada c Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada d Southlake Regional Health Centre, Newmarket, Ontario, Canada e For a complete listing of committee members, see Supplemental Appendix S1 ABSTRACT The Canadian Cardiovascular Society (CCS) Atrial Fibrillation Guide- lines Program has generated a comprehensive series of documents regarding the management of atrial fibrillation (AF) between 2010 and 2014. The guidelines provide evidence-based consensus management recommendations in a broad range of areas. These guidelines have proven useful in informing clinical practice, but often lack detail in specifications related to practical application, particularly for areas in which the evidence base is limited or conflicting. Based on feedback from the community, the CCS Atrial Fibrillation Guidelines Committee has identified a number of areas that require clarification to address commonly asked practical questions related to guidelines application. R  ESUM  E Entre 2010 et 2014, le programme de Lignes directrices de la Soci et e canadienne de cardiologie (SCC) en matière de fibrillation auriculaire (FA) a permis de cr eer une s erie de documents d etaill es sur la prise en charge de cette affection. Les lignes directrices contiennent des recommandations consensuelles de prise en charge fond ees sur des donn ees probantes dans plusieurs sphères d’application. Bien qu’in- formatives pour la pratique clinique, les lignes directrices manquent parfois de pr ecision quant aux questions d’ordre pratique, partic- ulièrement lorsque les donn ees probantes sont limit ees ou con- flictuelles. À la suite de r etroactions fournies par la communaut e m edicale, le comit e des lignes directrices en matière de fibrillation The Canadian Cardiovascular Society (CCS) Atrial Fibrilla- tion Guidelines Program has generated a comprehensive document regarding the management of atrial fibrillation (AF) in 2010, with subsequent focused updates to address clinically important advances in 2012 and 2014. 1-3 These documents contained evidence-based and formal recommendations ac- cording to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria, with “Practical Tips” to guide implementation. Based on feedback from the community, we identified areas that require clarifi- cation to addresses commonly asked practical questions related to clinical application of the guidelines. In this docu- ment we address these issues with a question and answer format. The responses use published evidence whenever possible, but where evidence is limited we have relied on the expertise of the CCS Atrial Fibrillation Guidelines Panel (see Supplemental Appendix S1 for a list of panel members) to provide practical guidance. What Duration of AF Is Clinically Significant? The detection of an irregularly irregular heart rhythm on heart rhythm monitoring (eg, via ambulatory electrocardio- gram [ECG] or implantable electronic device) suggests a diagnosis of AF. There is extensive evidence for a relationship between the duration of AF paroxysms and stroke risk. 4,5 Oral anticoagulation with vitamin-K antagonists or a novel non- vitamin K antagonists (NOACs) reduce stroke risk, but carry the disadvantages of increased risk of bleeding, cost, and/ or a need for monitoring. Therefore, it would be useful to define a standard arrhythmia duration for the diagnosis of AF, and to justify the initiation of stroke prevention therapy. Canadian Journal of Cardiology 31 (2015) 1207e1218 Received for publication May 28, 2015. Accepted June 10, 2015. Corresponding author: Dr Atul Verma, Southlake Regional Health Centre, Suite 602, 581 Davis Dr, Newmarket, Ontario L3Y 2P6, Canada. Tel.: þ1-905-953-7917; fax: þ1-905-953-0046. E-mail: atul.verma@utoronto.ca The disclosure information of the authors and reviewers is available from the CCS on their guidelines library at www.ccs.ca. http://dx.doi.org/10.1016/j.cjca.2015.06.005 0828-282X/Ó 2015 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.