This is a graphic example of normal inspiratory, or physiologic, splitting of S2 in which the first component, A2, is normally louder than the second component, P2.
Discussion
Abnormally wide splitting inspiratory splitting of the second heart sound occurs when pulmonary closure is delayed. This delay may be electrical, as with right bundle branch block, or mechanical, as in pulmonary stenosis. It also occurs when aortic closure is early, as seen in mitral regurgitation.