Physical examination findings in pulmonic stenosis

This phonocardiogram recorded over the left third intercostal space shows a crescendo- decrescendo systolic murmur. The pulmonary component (P2) of the second heart sound is delayed. The aortic component (A2) is obscured by the murmur. The lead II electrocardiogram has large S waves indicative of right ventricular hypertrophy.

ps2-n Phonocardiogram (upper) and concurrent electrocardiogram (lower). The phonocardiogram shows a systolic murmur and a split second heart sound, with delay of the pulmonic valve component (P2). The ECG shows a right axis deviation.	ps2a-n The systolic murmur shows a crescendo in early systole, highlighted in yellow. This is often difficult to appreciate in dogs.
ps2b-n	ps2c-n
ps2d-n The systolic murmur shows a decrescendo in late systole, highlighted in yellow. This is often difficult to appreciate in dogs.	ps2e-n Deep S wave consistent with right ventricular hypertrophy.

Radiographic findings in pulmonic stenosis

Pulmonic stenosis can be diagnosed by auscultation, electrocardiography, and radiography, and confirmed by Doppler echocardiography or intracardiac pressure recordings. Angiocardiograms like this one help determine the level of obstruction. Contrast material injected into the right ventricle in this case reveals doming at the level of the pulmonic valve indicating that this dog has valvular PS. Post-stenotic dilation of the main pulmonary artery also is evident.

ps3-n Right ventricular angiogram of a dog with pulmonic stenosis	ps3a-n Location of the domed pulmonic valve in a dog pulmonic stenosis, highlighted in yellow
ps3b-n Location of the post-stenotic dilation of the pulmonary artery in a dog pulmonic stenosis, highlighted in yellow

Spectral Doppler echocardiography in pulmonic stenosis

This Doppler echocardiogram shows a peak flow velocity (PFV) across the pulmonic valve of 5 meters/second. This indicates a pressure gradient of 100 mm of Hg (mm Hg = 4 x PFV^2). (Normal RV and PA systolic pressures are the same, ~25 mm Hg.) A gradient of 100 mm Hg indicates RV pressure in this case is ~125 mm Hg since PA pressure usually remains normal. A 100 mm Hg gradient is an indication for relief of the obstruction by surgery or balloon valvuloplasty.

ps4-n

ps4a-n High velocity systolic flow across the pulmonic valve in a dog pulmonic stenosis, highlighted in yellow

Cardiac catheterization in pulmonic stenosis

Cardiac catheterization helps determine the location and severity of obstruction. Pressure is recorded in the pulmonary artery then the catheter is withdrawn into the right ventricle ("pullout tracing"). Typically, systolic pressure in the pulmonary artery is normal, then it increases in the right ventricle. A pressure gradient is the difference in systolic pressure between the pulmonary artery and right ventricle. A one-step change in the systolic pressure indicates valvular stenosis. A two-step change indicates a subvalvular obstruction. The diastolic pressure drop to near zero indicates right ventricular location in the infundibular region. The subsequent pressure increase indicates the high-pressure right ventricle proximal to the obstruction.

ps5-n Right-sided retrograde catherization of a dog with subvalvular or infundibular pulmonic stenosis.	ps5a-n The pulmonary artery pressure tracing, highlighted in yellow, showing normal systolic and diastolic arterial pressures.
ps5b-n Right ventricular pressure tracing, highlighted in yellow, upstream of the stenosis. The systolic pressures are approximately 80mmHg.	ps5c-n Diastolic right ventricular pressures downstream of the stenosis. Diastolic pressures are close to zero (normal). Note that the systolic pressures in this portion of the right ventricle are equal to the pulmonary artery systolic pressures. The catheter has been pulled back across the valve at the point where the scale markers indicate the pressures. This indicates that the valve is not stenotic.
ps5d-n High systolic and normal diastolic pressures within the right ventricle at the point where the catheter has been pulled back across the obstruction (subvalvular or infundibular).