Heart valve disorders include Aortic regurgitation: Insufficiency of the aortic valve causing backflow of blood from the aorta into the left ventricle during diastole Aortic stenosis: Narrowing of the aortic valve, obstructing blood flow from the left ventricle to the ascending aorta during systole Mitral regurgitation: Insufficiency of the mitral valve causing flow of blood from the left ventricle (LV) into the left atrium during ventricular systole.