Valvar Pulmonary Stenosis Clinical Presentation

Updated: Jun 26, 2014
  • Author: Syamasundar Rao Patnana, MD; Chief Editor: Howard S Weber, MD, FSCAI  more...
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Presentation

History

Most children with pulmonic stenosis, particularly those with trivial and mild pulmonary stenosis, present with asymptomatic cardiac murmurs that are detected during routine examination.

Patients with moderate or severe pulmonary stenosis may have mild exertional dyspnea. Adults may be asymptomatic irrespective of the severity of their obstruction. [16, 20, 21]

Patients with severe or critical obstruction may present with signs of systemic venous congestion, which are usually interpreted as signs of congestive heart failure (CHF). The signs are due to severe right ventricular dysfunction or to cyanosis secondary to a right-to-left shunt across a patent foramen ovale or an atrial septal defect.

Lightheadedness, syncope, and chest pain that resembles angina pectoris are rare, even in patients with severe obstruction.

Of note, many patients with moderate or severe pulmonary stenosis remain asymptomatic.

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Physical

Degree of obstruction

Physical findings depend on the degree of obstruction. Most patients with pulmonary stenosis appear healthy and are well developed. Indeed, the chubby and rounded faces, described as moon facies, were initially thought to be characteristic for this anomaly, [15, 17] but this facial appearance is not a helpful diagnostic tool. [22]

Most patients with trivial, mild, or moderate stenosis, and many with severe stenosis, are acyanotic. However, some may have cyanosis secondary to an interatrial right-to-left shunt.

The jugular venous pulse is normal. However, in patients with decreased right ventricular compliance (ie, severe stenosis), a prominent α wave may be visualized in the neck pulsation. Patients may have a concomitant presystolic pulsation in the liver as well.

In patients with trivial or mild obstruction, the right ventricular impulse is normal. When the pulmonary stenosis is moderate to severe, a sustained and forceful right ventricular impulse and a right ventricular heave are felt.

A thrill may be felt in the suprasternal notch and at the left upper sternal border (pulmonic area). The precordial thrill is most likely to be associated with severe obstruction, although no consistent relationship is observed between the thrill and the degree of obstruction.

Upon auscultation, the first heart sound may be normal in intensity or may be loud. The second heart sound is widely split. The width of the split increases with worsening stenosis. The intensity of pulmonary component of the second heart sound may be loud (in mild stenosis) or may be soft, diminished, or absent, depending on the severity of obstruction. A fourth heart sound may be heard at the left lower sternal border in patients with severe obstruction and is usually associated with prominent α wave in the jugular pulse.

An ejection systolic click is heard along the left sternal border and varies with respiration (decreases or disappears during inspiration). With increasing severity, the click comes closer to the first heart sound.

An ejection systolic murmur of grade II/VI to V/VI is best heard at the left upper sternal border with radiation into infraclavicular regions, axillae, or back. The intensity of the murmur is not necessarily related to the severity of pulmonary valve obstruction, but the duration and timing of peaking of the murmur are related to the severity of stenosis.

An early diastolic decrescendo murmur of pulmonary regurgitation is not usually heard in the typical case of pulmonary stenosis. Previous surgical or balloon intervention or valvar calcification may result in such a murmur.

A holosystolic murmur at the left lower sternal border, which indicates tricuspid regurgitation, may be audible in some patients with extremely severe pulmonary stenosis.

Hepatosplenomegaly is not usually present and may develop in cases of CHF.

Peripheral pulmonary stenosis (commonly encountered in the neonate) is usually associated with a grade II/VI ejection systolic murmur that radiates into the posterior lung fields and axillae. The pathology of peripheral pulmonary stenosis is related to branch pulmonary arteries that are relatively small compared with the large main pulmonary artery, as well as to the acute angular takeoff of the branch pulmonary arteries from the main pulmonary artery specific to a neonate's anatomy. This condition and the associated murmur usually resolve spontaneously in the first month of life.

Clinical assessment of severity

The severity of the obstruction of the pulmonary valve can often be estimated by carefully analyzing the ausculatory findings. [23, 24] The timing of the ejection click, the extent of splitting of the second heart sound, the intensity of the pulmonary component of the second sound, the duration of the systolic murmur, and the timing of the peaking of the ejection murmur usually indicate the severity of pulmonary valve stenosi (see the image below).

In valvar pulmonic stenosis, the severity of obstr In valvar pulmonic stenosis, the severity of obstruction may be judged by auscultatory findings. In mild stenosis, the ejection click (EC) is clearly separated from the first heart sound (S1). The murmur starts with the click, peaks in early systole, and ends way before the aortic component of the second heart sound (A2) The pulmonary component of the second heart sound (P2) is normal to increased in intensity. In moderate pulmonic stenosis, the click is closer to the first heart sound, the ejection murmur peaks later in the systole and the murmur reaches the A2, and the second heart sound is widely split with soft pulmonary component. In severe valvar obstruction, the click is either absent or occurs so close to S1 that it cannot be heard separately, and the murmur peaks late in systole and extends beyond the A2. The second heart sound is widely split with an extremely soft or inaudible P2. Reproduced from Rao PS: Evaluation of cardiac murmur in children. Indian J Pediatr 1991 Jul-Aug; 58(4): 471-91.

With trivial and mild cases of pulmonary valve obstruction, the click is clearly separated from the first heart sound. Almost normal splitting of the second heart sound with normal or slightly increased pulmonary component of the second heart sound is heard. An ejection systolic, diamond-shaped murmur that peaks early in systole and that ends much before the aortic component of the second heart sound is appreciated.

Findings in moderate pulmonary valve stenosis include an ejection systolic click that is closer to the first heart sound than it is in mild forms, a widely split second sound with a diminished pulmonary component, and an ejection systolic murmur that peaks in mid-to-late systole and that ends just before the aortic component of the second heart sound.

In severe narrowing of the pulmonary valve, ausculatory features are an ejection systolic click that is absent or that occurs so close to the first heart sound that it becomes inseparable from it, markedly increased splitting with a soft or inaudible pulmonary component of the second heart sound, and a long ejection systolic murmur that peaks late in systole and that extends beyond the aortic component of the second heart sound so that the latter cannot be heard.

The duration and time of peaking of the ejection systolic murmur, and not its intensity, indicate the severity of the pulmonary valve obstruction. The longer the murmur and the later it peaks, the more severe the obstruction. Likewise, the shorter the interval between the first heart sound and ejection click, the wider the splitting of the second heart sound, and the softer the pulmonary component, the more severe the stenosis of the pulmonary valve.

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Causes

Pulmonary valve stenosis is primarily due to maldevelopment of the pulmonary valve tissue and the distal portion of the bulbus cordis, which is characterized by fusion of leaflet commissures, resulting in a thickened and domed appearance of the valve.

Although familial forms of pulmonary stenosis are described, it is generally considered to be multifactorial in origin. [25] Rates of recurrence in siblings are on the order of 2-3%. [26, 27] The prevalence of pulmonary stenosis in the offspring of a parent with pulmonary stenosis is 3.6%.

Aberrant flow patterns in utero may also be partly associated with maldevelopment of the pulmonary valve. [28]

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