Additional Heart Sounds–Part 2 (Clicks, Opening Snap and More)

Systolic clicks are high-pitched sharp sounds. They are classified as ejection and nonejection clicks. Ejections clicks commonly occur at the aortic and pulmonary valve, while nonejection clicks occur at the mitral and tricuspid valve. Opening snap is an additional sound heard in the diastole. It is described as an early diastolic, high-pitched sound, which is associated with opening of the mitral and/or tricuspid valve. Pericardial knock is a high-pitched early diastolic sound, which is characteristic of constrictive pericarditis. The opening and closing of prosthetic valves produce sounds which may vary in intensity and timing according to the type and design of the valve, patient’s rhythm, and hemodynamic status.