This is a graphic example of fixed splitting of S2. Fixed splitting of the second heart sound typically occurs in patients with atrial septal defect because the common atrial reservoir negates the usual influence of respiration on venous return and there is a constant increase in right ventricular flow that delays pulmonary closure.
Discussion
Fixed splitting of the second heart sound typically occurs in patients with atrial septal defect, because the common atrial reservoir negates the usual influence of respiration on venous return and there is a constant increase in right ventricular flow that delays pulmonary closure.