1962;24:349 57. 4. Rowe JC, Bland EF, Sprague HB, et al. The course of mitral stenosis without surgery: ten- and twenty-year perspectives. Ann Intern Med. 1960;52:741 9. 5. Szekely P. Systemic embolism and anticoagulant prophylaxis in rheumatic heart disease. Br Med J. 1964;1:1209 12. 6. Wilson JK, Greenwood WF. The natural history of mitral stenosis. Can Med Assoc J. 1954;71:323 31. 7. Omran H, Rang B, Schmidt H, et al. Incidence of left atrial thrombi in patients in sinus rhythm and with a recent neurologic deficit. Am Heart J. 2000;140:658 62. 8. Yusuf J, Goyal M, Mukhopadhyay S, et al. Effect of heart rate control on coagulation status in patients of rheumatic mitral stenosis with atrial fibrillation a pilot study. Indian Heart J. 2015;67(suppl 2):S40 5. 9. Rigolin VH, Higgenbotham MB, Robiolio PA, et al. Effect of inadequate cardiac output reserve on exercise tolerance in patients with moderate mitral stenosis. Am J Cardiol. 1997;80:236 40. 10. Laufer-Perl M, Gura Y, Shimiaie J, et al. Mechanisms of effort intoler- ance in patients with rheumatic mitral stenosis: combined echocardiog- raphy and cardiopulmonary stress protocol. JACC Cardiovasc Imaging. 2017;10:622 33. 11. Kitzman DW, Upadhya B, Zhao D. New concepts in an old disease: exer- cise intolerance in moderate mitral stenosis. JACC Cardiovasc Imaging. 2017;10:634 6. 12. Saggu DK, Narain VS, Dwivedi SK, et al. Effect of ivabradine on heart rate and duration of exercise in patients with mild-to-moderate mitral steno- sis: a randomized comparison with metoprolol. J Cardiovasc Pharmacol. 2015;65:552 4. 13. Parakh N, Chaturvedi V, Kurian S, et al. Effect of ivabradine vs atenolol on heart rate and effort tolerance in patients with mild to moderate mitral stenosis and normal sinus rhythm. J Card Fail. 2012;18:282 8. CLINICAL STATEMENTS AND GUIDELINES 14. Agrawal V, Kumar N, Lohiya B, et al. 