Pulmonary valve regurgitation
Pulmonary valve regurgitation, also known as pulmonary valve insufficiency or pulmonary valve incompetence, is a valvulopathy that describes leaking of the pulmonary valve diastole that causes blood to flow in the reverse direction from the pulmonary trunk and into the right ventricle.
Prevalence of pulmonary regurgitation is thought to have two demographical peaks, firstly in young patients with repaired congenital pulmonary stenosis or right ventricular outflow tract obstruction repairs, or secondly in patients with pulmonary arterial hypertension 1. As such, given the multitude of causes, the exact prevalence is difficult to determine.
Clinical features can vary dependent of the severely of the pulmonary regurgitation, and often only manifest when pulmonary regurgitation is severe 1,2. When symptomatic, it eventually leads to right-predominant clinical features of heart failure 1,2. Depending on the etiology, patients may have clinical features of pulmonary hypertension 1,2.
Clinical examination classically reveals a right ventricular heave on praecordial palpation, and an early diastolic murmur that is heard on praecordial auscultation known as the Graham Steell murmur 1-3. Occasionally the murmur heard may be holodiastolic, reflecting increased disease severity 1,2.
The characteristic hemodynamic feature of severe pulmonary regurgitation, similarly to the effect of aortic regurgitation on the left side of the heart, is enlargement of the right ventricle in response to right ventricular overload and an effort to maintain cardiac output 1,2. This results in right ventricular dysfunction, explaining the clinical features of this valvulopathy, and functional tricuspid regurgitation 1,2. At this point, there is also a decrease in the cardiac output 1,2.
Etiologies of pulmonary regurgitation can be considered primary, where there is valvular pathology, or secondary ('functional'), where there is dilation of the annulus as a result of pulmonary arterial hypertension or pulmonary artery dilation 1,2. Overall, secondary pulmonary regurgitation is more common than primary pulmonary regurgitation 1,2.
Primary causes include 1,2,4,5:
- iatrogenic (most common primary cause)
- infective endocarditis
- carcinoid heart disease (often alongside pulmonary stenosis)
- rheumatic heart disease
- congenital pulmonary regurgitation
Disorders leading to secondary (functional) pulmonary regurgitation include 1,2,4,5:
- any cause of pulmonary arterial hypertension (see individual article for an in-depth discussion)
- pulmonary artery dilation
Signs of pulmonary regurgitation on chest radiograph are often subtle, but include 1:
- right ventricular enlargement
- prominent pulmonary trunk
- features of tricuspid regurgitation may also be present
- features of congestive heart failure may also be present
Echocardiography is useful for evaluating the cause of pulmonary regurgitation, for assessing the regurgitant volume, and for assessing the right-sided cardiac chambers 4. The echocardiographic detection of minor or trivial pulmonary regurgitation is common, and present in up to 78% of people 4.
For pathological pulmonary regurgitation, various parameters are used in order to determine severity, such as 4:
- pulmonary valve normal
- right ventricular size normal
- central jet thin
- jet density soft
- jet deceleration slow
- pulmonary systolic flow compared to systemic flow slightly increased
- pulmonary valve may be normal or abnormal
- right ventricular size may be normal or abnormal
- central jet intermediate
- jet density dense
- jet deceleration variable
- pulmonary systolic flow compared to systemic flow intermediate
- pulmonary valve abnormal
- right ventricular size dilated
- central jet usually large with a wide origin
- jet density dense
- jet deceleration steep
- pulmonary systolic flow compared to systemic flow greatly increased
Additionally, the shape of the pulmonary annulus can also be measured with echocardiography, although this is often technically challenging 4.
Cross-sectional imaging demonstrate the same radiographic features appreciated on plain film and echocardiography, but in greater detail 5,6. In particular, cardiac MRI may be particularly useful for accurate measurements to assess the severity of the valvulopathy and for assessing areas of the heart that are technically challenging to review with echocardiography (e.g. the pulmonary annulus, the right ventricular outflow tract) 5,6.
Treatment and prognosis
The decision to treat pulmonary regurgitation is based on its severity 1. Management involves pharmacotherapy measures (especially diuretics and management of underlying pulmonary arterial hypertension) and consideration of surgery in primary disease 1. Details of this management is beyond the scope of this article.
- 1. Fauci AS. Harrison's principles of internal medicine. New York: McGraw-Hill, Medical Publishing Division; 2008.
- 2. Frigiola A, Giardini A, Taylor A, Tsang V, Derrick G, Khambadkone S, Walker F, Cullen S, Bonhoeffer P, Marek J. Echocardiographic assessment of diastolic biventricular properties in patients operated for severe pulmonary regurgitation and association with exercise capacity. (2012) European heart journal cardiovascular Imaging. 13 (8): 697-702. doi:10.1093/ehjci/jes002 - Pubmed
- 3. Steell, G. Murmur of high-pressure in pulmonary artery. (1888) Med. Chronicle. 9:182–188.
- 4. Zoghbi WA, Enriquez-Sarano M, Foster E, Grayburn PA, Kraft CD, Levine RA, Nihoyannopoulos P, Otto CM, Quinones MA, Rakowski H, Stewart WJ, Waggoner A, Weissman NJ. Recommendations for evaluation of the severity of native valvular regurgitation with two-dimensional and Doppler echocardiography. Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography. 16 (7): 777-802. doi:10.1016/S0894-7317(03)00335-3 - Pubmed
- 5. Saremi F, Gera A, Ho SY, Hijazi ZM, Sánchez-Quintana D. CT and MR imaging of the pulmonary valve. (2014) Radiographics : a review publication of the Radiological Society of North America, Inc. 34 (1): 51-71. doi:10.1148/rg.341135026 - Pubmed
- 6. Gupta H, Mayo-Smith WW, Mainiero MB, Dupuy DE, Abbott GF. Helical CT of pulmonary vascular abnormalities. (2002) AJR. American journal of roentgenology. 178 (2): 487-92. doi:10.2214/ajr.178.2.1780487 - Pubmed