Three events occur in diastole, each of which may be associated with a murmur. These are closure of the semilunar valve, opening of the atrioventricular valve and atrial contraction. A diastolic murmur that begins simultaneously with either the aortic or pulmonic component of the second heart sound indicates regurgitation of the respective valve. Let us listen together and observe the graphic image of the murmur of aortic regurgitation.