Patients with hypertrophic obstructive cardiomyopathy typically present with evidence of an abnormal apical impulse and usually a brisk carotid upstroke. The sytolic crescendo-decrescendo murmur is loudest at the mid-to-lower left sternal edge. Patients may also demonstrate the systolic murmur of mitral regurgitation and a fourth heart sound at the apex. The second heart sound may split paradoxically, that is, split in expiration and single in inspiration.