A combination of systolic and diastolic murmurs (auscultated over the left heart base) is heard in this heart sound, following a balloon valvuloplasty for severe pulmonary valve dysplasia.
The combination of a systolic ejection murmur with a diastolic decrescendo murmur is described as a to-and-fro murmur. The ejection component tapers in late systole, allowing recognition of S2 and differentiation from a continuous murmur.
This dog had mild outflow tract obstruction with severe pulmonary insufficiency following the balloon valvuloplasty, resulting in systolic and diastolic murmurs with almost equal intensity (both grade 3/6).