(See also Overview of Cardiac Valvular Disorders Overview of Cardiac Valvular Disorders Any heart valve can become stenotic or insufficient (also termed regurgitant or incompetent), causing hemodynamic changes long before symptoms. Most often, valvular stenosis or insufficiency... read more .)
The most common cause by far of pulmonic regurgitation is
Less common causes are
Congenital heart disease
Idiopathic pulmonary artery dilation
Rare causes are
Severe pulmonic regurgitation is rare and most often results from an isolated congenital defect involving dilation of the pulmonary artery and pulmonary valve annulus.
PR may contribute to development of right ventricular (RV) dilatation and eventually RV dysfunction–induced heart failure (HF), but in most cases, pulmonary hypertension contributes to this complication much more significantly. Rarely, acute RV dysfunction–induced HF develops when endocarditis causes acute PR.
Symptoms and Signs of Pulmonic Regurgitation
Pulmonic regurgitation is usually asymptomatic. A few patients develop symptoms and signs of RV dysfunction–induced HF Classification 
.
Palpable signs are attributable to pulmonary hypertension Pulmonary Hypertension Pulmonary hypertension is increased pressure in the pulmonary circulation. It has many secondary causes; some cases are idiopathic. In pulmonary hypertension, pulmonary vessels may become constricted... read more and RV hypertrophy. They include a palpable pulmonic component (P2) of the 2nd heart sound (S2) at the left upper sternal border and a sustained RV impulse that is increased in amplitude at the left middle and lower sternal border.
Auscultation
High-pitched, early diastolic decrescendo murmur
On auscultation, the 1st heart sound (S1) is normal. The S2 may be split or single. When split, P2 may be loud and audible shortly after the aortic component of S2 (A2) because of pulmonary hypertension, or P2 may be delayed because of increased RV stroke volume. S2 may be single because of prompt pulmonic valve closing with a merged A2-P2 or, rarely, because of congenital absence of the pulmonic valve. An RV 3rd heart sound (S3), 4th heart sound (S4), or both may be audible with RV dysfunction–induced HF or RV hypertrophy; these sounds can be distinguished from left ventricular heart sounds because they are located at the left parasternal 4th intercostal space and because they grow louder with inspiration.
The murmur of PR due to pulmonary hypertension is a high-pitched, early diastolic decrescendo murmur that begins with P2 and ends before S1 and that radiates toward the mid-right sternal edge (Graham Steell murmur); it is heard best at the left upper sternal border with the diaphragm of the stethoscope while the patient holds the breath at end-expiration and sits upright.
The murmur of PR without pulmonary hypertension is shorter, lower-pitched (rougher in quality), and begins after P2. Both murmurs may resemble the murmur of aortic regurgitation but can be distinguished by inspiration (which makes the PR murmur louder) and by Valsalva release. After Valsalva release, the PR murmur immediately becomes loud (because of immediate venous return to the right side of the heart), but the aortic regurgitation murmur requires 4 or 5 beats to do so. Also, a soft PR murmur may sometimes become even softer during inspiration because this murmur is usually best heard at the 2nd left intercostal space, where inspiration pushes the stethoscope away from the heart. In some forms of congenital heart disease, the murmur of severe PR is quite short because the pressure gradient between the pulmonary artery and the right ventricle equalizes rapidly in diastole.
Diagnosis of Pulmonic Regurgitation
Echocardiography
Pulmonic regurgitation is usually incidentally detected during a physical examination or Doppler echocardiography Echocardiography This photo shows a patient having echocardiography. This image shows all 4 cardiac chambers and the tricuspid and mitral valves. Echocardiography uses ultrasound waves to produce an image of... read more 
done for other reasons. Mild PR is a normal echocardiographic finding that requires no action.
An ECG and chest x-ray are usually obtained. ECG Electrocardiography The standard electrocardiogram (ECG) provides 12 different vector views of the heart’s electrical activity as reflected by electrical potential differences between positive and negative electrodes... read more may show signs of RV hypertrophy; chest x-ray Chest x-ray Chest imaging includes use of plain x-rays, computed tomography (CT) scanning, magnetic resonance imaging (MRI), nuclear scanning, including positron emission tomography (PET) scanning, and... read more may show RV enlargement and evidence of conditions underlying pulmonary hypertension.
Treatment of Pulmonic Regurgitation
Treatment of cause
Rarely valve replacement
Treatment is management of the condition causing pulmonic regurgitation. Pulmonic valve replacement is an option if RV dilation or dysfunction develops, particularly if the patient is symptomatic.
Key Points
Pulmonic regurgitation (PR) is usually caused by pulmonary hypertension.
Hemodynamic consequences are usually due to the cause rather than PR itself.
Heart sounds when PR is due to pulmonary hypertension include a high-pitched, early diastolic decrescendo murmur that begins with P2 and ends before S1 and that radiates toward the mid-right sternal edge; it is heard best at the left upper sternal border while the patient holds the breath at end-expiration and sits upright. The murmur of PR without pulmonary hypertension is shorter, lower-pitched, and begins after P2.
Treatment is directed at the cause; valve replacement is usually not needed.
