Most defects occur in the membranous portion of the septal wall.
A systolic murmur is best heard on the right side. A systolic murmur results because of increased quantity of blood flowing through the pulmonary conus. If the pressure between the two atria equalizes, the flow through the shunt may diminish, and may reverse leading to cyanosis. Fig 6 Stenosis Aortic Pulmonic Pulmonic stenosis occurs more commonly in the dog than aortic stenosis. Ventricular hypertrophy and post-stenotic dilation are associated findings.