What is the management of pulmonic stenosis?

Management of Pulmonic Stenosis

Balloon valvotomy is the treatment of choice for pulmonic stenosis when the RV-to-pulmonary artery peak-to-peak gradient exceeds 40 mm Hg in asymptomatic patients or exceeds 30 mm Hg in symptomatic patients. 1

Initial Diagnostic Evaluation

The diagnostic workup should establish severity and guide intervention decisions:

• ECG and transthoracic Doppler echocardiography are the recommended initial tests, with repeat evaluation every 5-10 years for ongoing surveillance 1
• Cardiac catheterization is indicated when Doppler peak jet velocity exceeds 3 m/second (estimated gradient >36 mm Hg), and balloon dilation can be performed during the same procedure 1
• Diagnostic catheterization alone (without intervention) is not recommended for initial evaluation 1

Severity Classification by Echocardiography

Doppler velocity and gradient thresholds define severity:

• Mild: <3 m/s or <36 mmHg mean gradient 2
• Moderate: 3-4 m/s or 36-64 mmHg mean gradient 2
• Severe: >4 m/s or >64 mmHg peak gradient 2

Important caveat: Doppler gradients can overestimate severity in patients with tubular stenosis or multiple levels of obstruction; correlate with tricuspid regurgitation velocity to estimate true RV systolic pressure 2

Indications for Balloon Valvotomy

The ACC/AHA guidelines provide clear gradient-based thresholds:

Class I Recommendations (Definitive Indications)

• Symptomatic patients (exertional dyspnea, angina, syncope, or presyncope) with RV-to-PA peak-to-peak gradient >30 mm Hg at catheterization 1
• Asymptomatic patients with RV-to-PA peak-to-peak gradient >40 mm Hg at catheterization 1

Class IIb Recommendation (May Be Reasonable)

• Asymptomatic patients with RV-to-PA peak-to-peak gradient 30-39 mm Hg at catheterization 1

Class III Recommendation (Not Recommended)

• Asymptomatic patients with RV-to-PA peak-to-peak gradient <30 mm Hg at catheterization 1

Natural History Considerations

Understanding disease progression informs timing of intervention:

• Most patients with mild-to-moderate stenosis remain stable over time, with only 14% showing significant gradient increases 1
• **Infants and young children (<2 years)** and those with initial gradients >40 mm Hg are at higher risk for progression 1, 3
• Patients beyond infancy with mild stenosis have only a 4% chance of gradient increase >20 mm Hg 1
• Sudden death is very unusual, even with severe untreated stenosis 1

Technical Approach to Balloon Valvotomy

For patients with severe stenosis and heart failure, specific modifications improve outcomes:

• Use sequential progressively larger balloon catheters rather than a single large balloon 4
• Employ an extra stiff guidewire to support the dilation assembly 4
• Alternative vascular access (internal jugular vein) may be necessary in some cases 4
• Monitor closely for hypotension, bradycardia, and respiratory complications during the procedure 4

Long-term outcomes: Balloon valvuloplasty in adolescents and adults achieves excellent results, with gradients decreasing from 91±46 mm Hg to 38±32 mm Hg immediately post-procedure, and further improvement to 30±16 mm Hg at long-term follow-up 5

Management of Branch and Peripheral Pulmonary Artery Stenosis

When stenosis involves branch or peripheral pulmonary arteries (not just the valve):

• Percutaneous stenting is the treatment of choice for focal branch/peripheral stenosis with >50% diameter narrowing, RV systolic pressure >50 mm Hg, and/or symptoms 1
• Surgical intervention by surgeons with congenital heart disease expertise is reserved for lesions not anatomically amenable to percutaneous approaches 1
• Restenosis is common; repeat interventions may be required 1

Long-Term Surveillance

After initial evaluation or intervention:

• Clinical evaluation and echocardiography-Doppler every 1-2 years based on severity to assess RV systolic pressure and function 1
• For unoperated mild stenosis, follow-up every 5-10 years is adequate 1

Critical Pitfalls to Avoid

• Do not rely on visual assessment of cyanosis; use continuous pulse oximetry 6
• Patent foramen ovale can allow right-to-left shunting when RV compliance is reduced, increasing risk of paradoxical emboli and cyanosis 1
• Long-standing severe untreated obstruction eventually leads to tricuspid regurgitation and RV failure 1
• Exertional syncope may occur with severe stenosis, particularly with dehydration or low systemic vascular resistance states (e.g., pregnancy) 1