Most patients with pulmonary regurgitation are asymptomatic. However, symptoms may include:
exertional dyspnea
progressive decrease in exercise tolerance
pedal edema and congestive hepatomegaly
ventricular arrhythmia
Cardiology
InShort
by Christabel Nyange, MD, MPH and
edited by Todd Pulerwitz MD
Pulmonary valve regurgitation, also called pulmonary regurgitation (PR), pulmonic regurgitation or leaky pulmonary valve occurs when the pulmonic valve fails to close completely during diastole or for other reasons, allows blood to flow backwards into the right ventricle.
Signs and Symptoms
Most patients with pulmonary regurgitation are asymptomatic. However symptoms may include:
exertional dyspnea - as a result of reduced cardiac output stemming from the volume overload to the right heart
progressive decrease in exercise tolerance
pedal edema, congestive hepatomegaly, and rarely, raised jugular venous distension (JVD) in severe PR
symptomatic ventricular arrhythmia
Physical findings in PR include:
A diastolic decrescendo murmur heard in the 2nd and 3rd left intercostal spaces on auscultation
A right-sided S3 could also be appreciated, indicating volume overload
The pulmonary regurgitation murmur increases in intensity on inspiration due to the negative intrathoracic pressure generated (causing increased preload) and decreases in intensity with Valsalva maneuver
Jugular venous distension with large v waves (Lancisi sign) can be seen in patients with PR secondary to pulmonary hypertension if the right ventricular pressure is high enough to cause severe tricuspid insufficiency as well
The Graham Steell murmur: is a high pitched, blowing, early diastolic, decrescendo murmur (beginning immediately after P2), most prominent in the left 2 to 4 intercostal spaces, found with pulmonary hypertension. when there is dilatation of the pulmonary annulus causing high-velocity regurgitant jet.
It increases in intensity with inspiration, exhibits little change after amyl nitrite inhalation or vasopressor administration, is diminished during the Valsalva strain, and returns to baseline intensity almost immediately after release of the Valsalva strain.
Diagnostic Evaluation
An echocardiogram is the investigation of choice for pulmonary regurgitation Echocardiogram frequently determines the severity, cause, mechanism, and determines progression to ventricular remodeling and heart failure. The severity of pulmonary regurgitation can be determined by a number of qualitative and semi-quantitative assessments, one of them is the width at the right ventricular outflow tract (RVOT) occupied by the regurgitant jet. It must be considered that eccentric jets may result in underestimation of PR jet severity.
Mild PR - Normal right ventricular dimensions with narrow regurgitant jet width by color Doppler of < 25% of the pulmonary annulus
Moderate PR - Normal or dilated right ventricle with intermediate regurgitant jet width (less than 50% of pulmonic valve annulus)
Severe PR- Dilated right ventricle (except in acute PR) with large regurgitant jet width (greater than 50% of pulmonic valve annulus)
Other investigations that can be used are:
EKG: useful in patients who present with arrhythmias in the setting of right ventricular dilation secondary to volume overload.
Commonly seen EKG findings include:
rSR configuration in the right precordial leads (reflecting RV diastolic overload) in PR in the absence of pulmonary artery hypertension (PAH)
P-pulmonale (tall p waves- indicating right atrial enlargement), increased r to s ratio in the right precordial leads along with right axis deviation (indicating RV hypertrophy), if PR is secondary to PAH
Chest x-ray: lateral chest x-ray could reveal right ventricular dilation as reduced retrosternal space. Both pulmonary artery and right ventricular enlargement are visible, but these signs are nonspecific. Fluoroscopy may demonstrate pronounced pulsation of the main pulmonary artery.
Cardiac MRI: can be used in moderate and severe PR. It helps in assessing pulmonary artery dilation and severity of PR by quantifying the regurgitant jet
Angiography: varying degrees of opacification of the right ventricle are seen following the injection of contrast into the pulmonary artery due to the regurgitant jet.
Causes and Risk Factors
The most common cause of pulmonic regurgitation (PR) is the dilation of the valve annulus, however, it can be classified into physiologic, primary, and secondary causes.
Physiological pulmonary regurgitation is considered an incidental finding on echocardiogram.
Primary causes include:
Iatrogenic: the most common causes are surgical valvotomy and balloon valvuloplasty
infectious (infective endocarditis) with possible perforation or valve distortion
Immune-mediated (rheumatic heart disease)
Systemic (carcinoid disease)
Congenital pulmonic regurgitation
Post intervention: whether percutaneous or surgical valve replacement with valve failure or after operation or intervention for tetralogy of Fallot and valvular pulmonic stenosis
Secondary or functional PR occurs in patients with a morphologically normal pulmonic valve who have:
Idiopathic pulmonary artery dilatation and/or
Pulmonary arterial hypertension, as a result of:
Idiopathic Pulmonary arterial hypertension (PAH)
Left heart disease (left heart failure, aortic and mitral valve disease)
Lung disease (chronic obstructive lung disease, interstitial lung disease, obstructive sleep apnea)
Chronic thromboembolism of lungs
Other disorders of the pulmonary vasculature (sarcoidosis, sickle cell disease, schistosomiasis)
Complications
Untreated pulmonary regurgitation can result in:
right ventricular dilation
ventricular arrhythmias
right heart failure
congestive hepatomegaly
anasarca
left ventricular systolic dysfunction, and
sudden cardiac death -- from ventricular arrhythmias
Treatment Options
Recommended treatment modalities as per the AHA/ACA guidelines are based on the severity of symptoms and the progression of PR.
In asymptomatic patients with PR, treatment is not recommended unless 2/4 of the following criteria are met:
mild or moderate RV or LV systolic dysfunction
severe RV dilation (right ventricular end-diastolic volume >160ml/m2),
right ventricular systolic pressure (RVSP) due to right ventricular outflow tract (RVOT) >2/3 of systemic pressure or
progressively reduced exercise tolerance
Symptomatic patients with PR can be considered for intervention -- whether by surgical pulmonic valve replacement with a bioprosthetic valve or now more frequently with a percutaneous pulmonic valve replacement (such as a Melody valve).
Mechanical valves are rarely used. A bioprosthesis valve is preferred due to the durability of the prosthesis, low risk of valve failure, and no anticoagulation as compared to mechanical valves.
Medical therapy is only recommended if the cause of pulmonary regurgitation is secondary to a primary medical condition such as pulmonary arterial hypertension or carcinoid disease or patient considered too high risk for interventional approach.
In patients that are symptomatic with severe PR and are poor surgical candidates (due to age or comorbidities), medications targeting heart failure such as diuretics, ACEi/ARBs, and beta-blockers are recommended in appropriate situations.
Sources and further reading:
Corno AF. Pulmonary Valve Regurgitation: Neither Interventional Nor Surgery Fits All. Front Pediatr. 2018;6:169. Published 2018 Jun 7. doi:10.3389/fped.2018.00169
Saji AM, Sharma S. Pulmonary Regurgitation. [Updated 2020 Dec 14]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK557564/
Pendela VS, Ayyad R. Pulmonic Regurgitation. [Updated 2020 May 6]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK553136/