This heart sound includes a grade 3-4 harsh, high-frequency, crescendo-decrescendo (ejection) murmur heard throughout systole (auscultated at the left heart base over the pulmonic valve) with a somewhat harsher S2-associated “snap” compared with other severe PS examples.
In this example (ie, of a dog with severe PS), the stenotic valve snaps open and domes forward during ejection, creating the opening snap.