An- ticoagulation can also decrease the incidence of throm- boembolic events in patients with rheumatic MS if there has been a prior embolic event or if an LA throm- bus was visualized. In symptomatic patients with MS who are in normal sinus rhythm and have tachycardia, heart rate control with beta blockers, calcium channel blockers, or ivabradine will lengthen the diastolic fill- ing period and lower LA pressure. However, routine use of heart rate control for patients with rheumatic MS in normal sinus rhythm in the absence of tachycardia may result in chronotropic incompetence, preventing an ad- equate cardiac output response to exercise. Recommendation-Specific Supportive Text 1. Patients with rheumatic MS with AF and prior embolic events are at high risk of arterial embo- lization when AF or an LA thrombus is present. Treatment with VKA anticoagulation will decrease the incidence of these events.3 7,16 It is controver- sial whether long-term anticoagulation should be given to patients with rheumatic MS in normal sinus rhythm on the basis of LA enlargement or spontaneous contrast on TEE.17,18 Patients with very large left atria have more spontaneous echo- cardiographic contrast and lower LA appendage which have been associated with a higher rate of embolic events, but no data directly link large left atria to embolic events. Non vitamin K oral anticoagulation has not been studied in patients with rheumatic MS, and these patients were excluded from the randomized AF trials. 