systolic murmur, a cardiac murmur occurring during systole. Systolic murmurs include ejection murmurs, often heard in pregnant women or in people with anemia, thyrotoxicosis, or aortic or pulmonary stenosis; pansystolic murmurs, heard in people with incompetence of the mitral or tricuspid valve; and late systolic murmurs, also caused by mitral valve incompetence and, less commonly, by tricuspid regurgitation.