Pulmonary Stenosis

Pulmonic stenosis in adults is most often due to congenital disease, either residual stenosis after reparative surgery in childhood or clinically insignificant obstruction. Pulmonic stenosis may occur in conjunction with other congenital lesions such as ventricular inversion (congenitally corrected transposition of the great arteries) or tetralogy of Fallot. (Otto, Clinical Echocardiography 6e)

Stenosis can result from either congenital anomalies or from disease-related increase in cusp rigidity. Congenital pulmonary stenosis (PS) is a common anomaly accounting for 7-12% of congenital heart disease (CHD) and can occur in isolation or as a common concomitant (25-30%) with other CHD lesions. The stenotic valve may be bicuspid, unicuspid, or tricuspid but dysplastic. (EACVI Textbook of Echocardiography)

Rheumatic heart disease involvement of the PV is less common than with the mitral or aortic valves. Extrinsic obstruction of the PV may be produced by cardiac tumours or by aneurysms of the sinus of Valsalva. (EACVI Textbook of Echocardiography)

Right-sided valvular heart lesions are preferentially observed; tricuspid regurgitation and pulmonary stenosis in patients with carcinoid heart disease. (EACVI Textbook of Echocardiography)

Pulmonary stenosis is usually secondary to congenital obstruction, which may be subvalvular, valvular, or supravalvular. Poststenotic PA dilatation may be present. (Practical Perioperative TOE)

The level of RV outflow obstruction ranges from subvalvular (in the muscular outflow tract), valvular to supravalvular (either in the main PA or its major branches). Pulmonic stenosis sometimes occurs as an isolated anomaly but more often is part of a complex of defects (e.g., tetralogy of Fallot) or is associated with other abnormalities (e.g., corrected transposition). (Otto, Clinical Echocardiography 6e)

The level of outflow obstruction is determined using pulsed Doppler and color flow to identify the anatomic site at which the flow velocity increases and the poststenotic flow disturbance appears. The obstruction itself is seen on 2D or 3D imaging as a muscular subpulmonic ridge; as deformed, doming pulmonic valve leaflets; or as a narrowing in the PA. (Otto, Clinical Echocardiography 6e)

The aetiology of RVOT obstruction can be distinguished into two groups: Congenital: valvular, infundibular, or supravalvular; distal PA branch stenosis. (EACVI Textbook of Echocardiography)

Differentiation of valvular pulmonic stenosis from subvalvular or supravalvular obstruction can be difficult by 2D echo. Careful examinations with color flow and conventional pulsed Doppler can be very helpful in defining the site of the poststenotic flow disturbance (and thus the site of obstruction). (Otto, Clinical Echocardiography 6e)

localization of the stenosis level (valvar, subvalvar, or supravalvar) using CFM and pulsed wave Doppler. (EACVI Textbook of Echocardiography)

Pulmonary stenosis is usually congenital and most often valvular. Work through it in order: localise the level of obstruction (subvalvular, valvular, supravalvular or branch), define the valve morphology, grade severity from the peak Doppler velocity and gradient, assess the pressure-loaded hypertrophied right ventricle, then integrate with associated congenital lesions to decide on balloon valvuloplasty.

Evaluation of PV should be performed in conjunction with the RVOT, the RV, and the pulmonary branches. Two-dimensional (2D) transthoracic echocardiography standard and modified views are: parasternal short-axis view, with transducer position at the base of the heart where the bifurcation of the PA is also visualized; parasternal long-axis view with angulation toward the right shoulder; subcostal view (long- and short-axis views) with anterior angulation; apical five-chamber view, through clockwise angulation of transducer to bring in the RVOT. (EACVI Textbook of Echocardiography)

2D echo imaging of the pulmonic valve shows thickened leaflets with systolic bowing. (Otto, Clinical Echocardiography 6e)

In moderate to severe PS, the commissures become fused and the PV functions effectively as a unicuspid or bicuspid and doming funnel-shaped valve. This doming results in a restrictive orifice at the distal portion of the valve. Severe right ventricular (RV) hypertrophy may develop secondary to pressure load and lead to dynamic subpulmonic/infundibular stenosis. (EACVI Textbook of Echocardiography)

Primary echocardiographic findings in PS are systolic doming of the valve, thickened cusps with limited mobility, and increased peak velocity across the valve (> 2.0 m/s). Secondary findings are RV hypertrophy (wall thickness > 6 mm) and/or RV dilation, high RV systolic pressure estimated from tricuspid regurgitation, high RA pressure estimated from inferior vena cava size and respiratory collapse, and evidence of post-stenotic PA dilation. (EACVI Textbook of Echocardiography)

When valvular, the pulmonic valve leaflets are thickened with systolic doming. (Otto, Clinical Echocardiography 6e)

On Doppler interrogation, the antegrade velocity is increased with corresponding maximum and mean pressure gradients via the Bernoulli equation. Pulmonic valve area is not usually calculated, but the continuity equation principle can be applied in this situation, by using an appropriate intracardiac location for stroke volume determination. (Otto, Clinical Echocardiography 6e)

continuous wave (CW) Doppler interrogation across the RVOT and mPA to estimate peak and mean pressure gradients. The shape of Doppler envelope will differentiate between fixed (valvar) or dynamic (muscular subvalvar) obstruction. Often in complex multilevel RVOT obstruction, there will be an overlap of both dynamic and fixed components. (EACVI Textbook of Echocardiography)

Continuous wave Doppler signal from cursor across the right ventricular outflow tract, showing multi-level obstruction with 'dagger-shaped' late systolic accentuation from dynamic muscular subpulmonary obstruction and higher velocity 'bullet shaped' Doppler envelope from fixed valvar obstruction. (EACVI Textbook of Echocardiography)

The level of outflow obstruction is determined using pulsed Doppler and color flow to identify the anatomic site at which the flow velocity increases and the poststenotic flow disturbance appears. (Otto, Clinical Echocardiography 6e)

Quantification of pulmonary stenosis requires estimating the peak or mean transvalvular pressure gradient with CW Doppler. However, with TEE, optimal alignment of the Doppler signal with valvular flow may not be possible. (Practical Perioperative TOE)

A PV area of 1 cm2/m2 or less and a peak pressure gradient greater than 60 mmHg indicate a severe PS. (EACVI Textbook of Echocardiography)

Primary echocardiographic findings in PS are systolic doming of the valve, thickened cusps with limited mobility, and increased peak velocity across the valve (> 2.0 m/s). (EACVI Textbook of Echocardiography)

The peak gradient across the valve is approximately 65 mmHg (mild <25, moderate 25-50, severe >50) consistent with severe pulmonary stenosis. (Oxford Critical Care Echo)

Valve area (cm2) 3.5-4.5 normal value; < 1 cm2/m2 define severe PS. Peak systolic velocity (m/s) 0.75 (0.6-1.1) normal; Increased in PS and increased pulmonary flow. (EACVI Textbook of Echocardiography)

when serial stenoses are present, quantitation of the contribution of each level of obstruction to the overall degree of stenosis is difficult using Doppler echo methods. (Otto, Clinical Echocardiography 6e)

the proximal flow pattern in congenital stenosis often is characterized by a greater increase in velocity because of anatomic tapering of the proximal flow region (e.g., in aortic coarctation or with congenital pulmonic stenosis). In these situations, accurate pressure gradient calculations should include the proximal velocity (Vprox), as well as the maximum jet velocity (Vjet) in the Bernoulli equation. (Otto, Clinical Echocardiography 6e)

Because the RV outflow velocity is elevated, the maximum pulmonic valve gradient should be calculated using the proximal velocity (V2prox) in the Bernoulli equation. If the proximal velocity is not included, the gradient would be overestimated at 38 mmHg. (Otto, Clinical Echocardiography 6e)

Severe TR may cause underestimation of pulmonary valve stenosis severity by decreasing pulmonary flow and, hence, pressure gradient. (EACVI Textbook of Echocardiography)

Quantification of pulmonary stenosis requires estimating the peak or mean transvalvular pressure gradient with CW Doppler. However, with TEE, optimal alignment of the Doppler signal with valvular flow may not be possible. (Practical Perioperative TOE)

If significant obstruction is present, compensatory RV hypertrophy typically is seen. (Otto, Clinical Echocardiography 6e)

Note that in the presence of pulmonic stenosis, the tricuspid regurgitant jet velocity remains an accurate reflection of the RV to RA systolic pressure difference but no longer indicates PA systolic pressure. (Otto, Clinical Echocardiography 6e)

When pulmonic stenosis (PS) is present, the peak gradient (deltaP-PS) is subtracted from the estimated RV systolic pressure: PAP-systolic = [4(VTR)2 + RAP] - deltaP-PS. (Otto, Clinical Echocardiography 6e)

Secondary findings are RV hypertrophy (wall thickness > 6 mm) and/or RV dilation, high RV systolic pressure estimated from tricuspid regurgitation, high RA pressure estimated from inferior vena cava size and respiratory collapse, and evidence of post-stenotic PA dilation. (EACVI Textbook of Echocardiography)

Severe right ventricular (RV) hypertrophy may develop secondary to pressure load and lead to dynamic subpulmonic/infundibular stenosis. (EACVI Textbook of Echocardiography)

Pulmonic stenosis sometimes occurs as an isolated anomaly but more often is part of a complex of defects (e.g., tetralogy of Fallot) or is associated with other abnormalities (e.g., corrected transposition). (Otto, Clinical Echocardiography 6e)

The essence of tetralogy of Fallot is anterior displacement of the conal septum. This malformation results in a VSD, an aorta that overrides the VSD, RV hypertrophy, and pulmonary stenosis, which is usually subvalvular and often also valvular. There may also be hypoplasia of the branch PAs. (Practical Perioperative TOE)

Poststenotic dilatation of the main pulmonary artery is also present. This is probably the result of an associated inherent medial abnormality analogous to the ascending aortic dilatation associated with bicuspid aortic valve. (Oxford Critical Care Echo)

Congenital pulmonary stenosis (PS) is a common anomaly accounting for 7-12% of congenital heart disease (CHD) and can occur in isolation or as a common concomitant (25-30%) with other CHD lesions. (EACVI Textbook of Echocardiography)

In the paediatric population, PR is common after surgical or percutaneous relief of pulmonary stenosis and following repair of Tetralogy of Fallot. (Oxford Critical Care Echo)

A PV area of 1 cm2/m2 or less and a peak pressure gradient greater than 60 mmHg indicate a severe PS. (EACVI Textbook of Echocardiography)

Annulus diameter (cm) < 2.3 normal value; Determine the balloon size for valvuloplasty, dilated annulus causes PR. (EACVI Textbook of Echocardiography)

the relief of pulmonary stenosis by pulmonary balloon valvuloplasty or by pulmonary valve replacement may reduce the severity of TR through a reduced systolic transtricuspid driving pressure and reduction in right ventricular size. (EACVI Textbook of Echocardiography)

Acquired mild to moderate PR due to annular dilation is seen with pulmonary hypertension. Severe PR although less common is observed with congenital PV anatomical abnormalities and of course after surgical valvotomy or balloon valvuloplasty. (EACVI Textbook of Echocardiography)

Triage status: Orphan verbatim excerpts gathered for the Pulmonary Stenosis page that did not map cleanly to a single Q&A above. Web guideline sources (EAE/ASE valve stenosis recs; BSE tricuspid & pulmonary guideline 2020) could not be retrieved (reCAPTCHA / empty response) and are not represented below.

The slight displacement of the leaflet in diastole (after atrial contraction), called the A-wave, is increased (>7 mm) when pulmonic stenosis is present and is decreased (<2 mm) when pulmonary hypertension is present. (Otto, Clinical Echocardiography 6e)

Full assessment of PV cusps and commissures can be visualized by real-time three-dimensional (3D) TOE. The annulus appears oval-shaped and the actual valve area can be visualized and measured. (EACVI Textbook of Echocardiography)

identification of PS or PR with Doppler colour flow mapping (CFM); severe regurgitation may have CFM reversal originating in the branch PAs. (EACVI Textbook of Echocardiography)

Estimated pulmonary systolic pressure (PAP) is calculated by subtracting the pulmonic valve gradient from the estimated RV pressure because pulmonic stenosis is present. Thus, estimated PA systolic pressure is normal even though the tricuspid regurgitant jet indicates an RV systolic pressure of 51 mmHg. (Otto, Clinical Echocardiography 6e)