Rhythm control for post-operative atrial fibrillation. Still a promising future?
Amr S Omar1,2,3, Abdulaziz AlKhulaifi1
1Department of Cardiothoracic Surgery/ ICU Section,Heart Hospital, Hamad Medical Corporation, Doha, (PO: 3050), Qatar.2Department of Clinical Medicine, Weill Cornell Medical College Qatar.3Department of Critical Care Medicine, Beni Suef University, Egypt.
Key Words : POAF, rate control, rhythm control.
Correspondence to: Amr Omar(firstname.lastname@example.org)Department of Cardiothoracic Surgery/ICU Section, Heart Hospital, Hamad Medical Corporation, Doha, (PO: 3050), Qatar. Tel: (+974) 44395897 Fax: (+974) 44395362 Email: email@example.com
In the recently published guidelines for the management of atrial fibrillation (AF) rate control strategy for post-operative atrial fibrillation (POAF) plus anticoagulation was given level of evidence B, class II a.  Moreover the Canadian Cardiovascular Society (CCS) Atrial Fibrillation (AF) Guidelines Committee recommended that POAF could be managed equally with rate or rhythm control strategies . Both guidelines changed in reference to a recently published randomized controlled trial by Gillinov et al., where the authors did not find significant difference in their primary and secondary end points, the former end point was the length of hospitalization within 60 days after randomization,  the potential side effects of antiarrythmicss and cardioversion were beyond favoring this strategy over rhythm control. According to Mann et al., 2007 when AF causes life-threatening deterioration in hemodynamics, emergency cardioversion should be done, irrespective of the AF duration. Electrical cardioversion should also be considered also with hemodynamic instability that is not life threatening. 
The guidlines mentioned that asymptomatic POAF would be managed with rate control as a first choice, however Gillinov, put similar preferences for rate and rhythm control, the authors ignored the results of hemodynamically unstable patients and did not define a protocol to exclude them, we noted that the authors of the mentioned trial did not mention anything about the symptoms. ,
Gillinov, did not subdivide the patients according to post-operative cardiac dimensions and functions which could greatly influence the outcome, they also did not consider prior structural heart disease. There is recent data suggests that rhythm control would provide better outcomes in selected subgroups of heart failure patients.  Moreover the atrium account for for 25% of end diastolic volume in, a minimum effect will be noted when AF develop, but marked reduction in the cardiac output observed in case of impairment of diastolic filling by mitral stenosis.  The latter effects are more pronounced with tachycardia. Cessation of cardiac output in POAF referred to loss of atrial systole, augmentation of pulmonary capillary wedge pressure and increased valvular regurge. 
Finally, Giilinov did not report any complication for electrical cardioversion and side effects of antiarrhythmic were not great as claimed in their hypothesis to support favoring rate control.
The trial recruited total of 2109 patients from 24 centers in the US and Canada, on average only 88 patients per center, with POAF incidence 33%. We believe that a larger extended trial that incorporate the cardiac output and functions parameters, excluding hemodynamically unstable patients, longer term follow up with subgroup analysis could come with some interesting results.
Abdulaziz Alkulaifi is cheif cardiac surgery department , HMC.
To all remembers of CT surgery, Heart hospital, Hamad medical corporation.