The Carey Coombs Murmur is a murmur that can occur in the setting of acute rheumatic fever. The mitral valve becomes inflamed causing thickening of the leaflets. The actual murmur is produced by increased blood flow across the thickened mitral valve. This can be distinguished from rheumatic mitral valve stenosis by the absence of an opening snap. The murmur is heard as a mid diastolic murmur heard at the cardiac apex with the bell of the stethoscope with the patient in the left lateral decubitus position at end expiration. As the rheumatic valvulitis resolves, the murmur disappears.