Congenital pulmonary valve stenosis is a common congenital heart disease, accounting for up to 25% of congenital heart defects in adults.
Pathological Anatomy
The primary pathological changes in this condition can be classified into three types: valvular, subvalvular, and supravalvular stenosis.
Pathophysiology
The main pathophysiological feature is obstruction of blood outflow from the right ventricle, leading to increased right ventricular pressure, compensatory right ventricular hypertrophy, and eventually right heart failure.
Clinical Manifestations
Moderate Stenosis
Patients may experience dyspnea and fatigue during physical activity.
Severe Stenosis
Symptoms include syncope or even sudden death during vigorous activity.
Typical Physical Signs
A systolic ejection murmur is heard in the second intercostal space along the left sternal border, with wide radiation to the neck, the entire precordium, and even the back. A thrill is often palpable, and the second heart sound in the pulmonary valve area is diminished.
Auxiliary Examinations
Electrocardiography (ECG)
Findings may include right axis deviation, right ventricular hypertrophy, right atrial enlargement, and incomplete right bundle branch block.
Chest X-ray
Chest x-ray shows prominent pulmonary artery segment, small pulmonary vascular markings, and unusually clear lung fields. The heart apex may shift upward and to the left, with significant cardiac enlargement.
Echocardiography
Right ventricular hypertrophy and an increased transvalvular pressure gradient can be observed.
Diagnosis and Differential Diagnosis
A diagnosis can be confirmed based on typical murmurs, x-ray findings, and echocardiography. Differential diagnoses include primary pulmonary artery dilation, atrial or ventricular septal defects, tetralogy of Fallot, and Ebstein's anomaly.
Treatment
Interventional therapy is preferred. For patients in whom balloon valvuloplasty is unsuccessful or unsuitable, surgical treatment is recommended if the pressure gradient across the stenosis exceeds 40 mmHg.
Prognosis
Both interventional and surgical treatments yield good outcomes. If severe stenosis is left untreated, it can lead to right heart failure and death.