The increased volume and pressure is best depicted by pressure-volume loops . If there is significant regurgitation across the semilunar valve, then the rate of decline in pressure within the aorta or pulmonary artery will be greater as illustrated in the figure to the right for aortic regurgitation. The backward flow of blood into the ventricular chamber during diastole results in a diastolic murmur as shown by the green area between S 2 and S 1 in the above figure. A distinction must be made between acute and chronic regurgitation.
Acute regurgitation is associated with large increases in proximal ventricular and atrial pressures.
The ventricle and atria function on the stiffer portion of their compliance curves so that the increased volume results in a large rise in pressure. With chronic regurgitation, the ventricles and atria dilate so that the increased volume does not result in a dramatic rise in pressure. In other words, remodeling of the chambers results in increased compliance and a normalization of filling pressures. The regurgitant flow results in a holosystolic murmur . There is also a large increase in the v-wave of the atrial pressure.