ECG and chest x-ray findings are normal in mild stenosis. Moderate to severe stenosis results in right axis deviation and right ventricular hypertrophy. The heart size is usually normal on chest x-ray, although dilation of the main pulmonary artery may be seen. Echocardiography provides assessment of the site of stenosis, degree of hypertrophy, and valve morphology, as well as an estimate of the pressure gradient.
Valvular pulmonary stenosis usually does not progress, especially if it is mild. Balloon valvuloplasty is usually successful in reducing the gradient to acceptable levels for more significant or symptomatic stenosis. Surgical repair is required if balloon valvuloplasty is unsuccessful or when subvalvular (muscular) stenosis is present.
Valvular, subvalvular, or supravalvular aortic stenosis represents approximately 5% of all congenital heart disease. Lesions result from failure of development of the three leaflets or failure of resorption of tissue around the valve.
Mild to moderate obstructions cause no symptoms. More severe stenosis results in easy fatigability, exertional chest pain, and syncope. Infants with critical aortic stenosis may present with symptoms of heart failure.
A systolic ejection murmur is heard at the right second intercostal space along the sternum and radiating into the neck. The murmur increases in length and becomes higher in frequency as the degree of stenosis increases. With valvular stenosis, a systolic ejection click often is heard, and a thrill may be present at the right upper sternal border or in the suprasternal notch. The aortic component of S2 may be decreased in intensity.
ECG and chest x-ray findings are normal with mild degrees of stenosis. Left ventricular hypertrophy develops with moderate to severe stenosis and is detected on the ECG and chest x-ray. Dilation of the ascending aorta or aortic knob due to an intrinsic aortopathy may be seen on chest radiographs. Echocardiography shows the site of stenosis, valve morphology, and the presence of left ventricular hypertrophy, and it allows an estimate of the pressure gradient.
The degree of aortic stenosis frequently progresses with growth and age. Aortic insufficiency often develops or progresses. Serial follow-up with echocardiography is indicated. Balloon valvuloplasty is usually the first interventional procedure for significant stenosis. It is not as successful as pulmonary balloon valvuloplasty and has a higher risk of significant valvular insufficiency. Surgical management is necessary when balloon valvuloplasty is unsuccessful or significant valve insufficiency develops.
Coarctation of the aorta occurs in approximately 10% of all congenital heart defects. It is almost always juxtaductal in position. During development of the aortic arch, the area near the insertion of the ductus arteriosus fails to develop correctly, resulting in a narrowing of the aortic lumen.
Timing of presentation depends on the severity of obstruction and associated cardiac defects. Infants presenting withcoarctation of the aorta frequently have hypoplastic aortic arches, abnormal aortic valves, and VSDs. They may bedependent on a patent ductus arteriosus to provide descending aortic flow. Symptoms develop when the aortic ampullaof the ductus closes. Less severe obstruction causes no symptoms.
Symptoms, including poor feeding, respiratory distress, and shock, may develop before 2 weeks of age. Classically thefemoral pulses are weaker and delayed compared with theright radial pulse. The blood pressure in the lower extremities is lower than that in the upper extremities. If cardiac function is poor, however, these differences may not be asapparent until appropriate resuscitation is accomplished. Inthis situation, there may be no murmur, but an S3 is often present.