A late systolic click is a high-pitched sound that is heard at the late part of systole. It is almost always caused by mitral valve prolapse, a common structural abnormality of the heart. Aortic stenosis causes a loud murmur throughout systole. Mitral valve stenosis causes an opening snap and a quiet murmur in diastole. Pulmonary hypertension causes a complex assortment of abnormal sounds including pronounced pulmonic component of the second heart sound (P2), tricuspid valve regurgitation murmur, pulmonary valve regurgitation murmur (Graham Steell murmur), and S4 gallop.