From the Guidelines
Pulmonic regurgitation is characterized by a decrescendo diastolic murmur that is typically soft, blowing, and high-pitched, beginning immediately after the second heart sound (P2) and decreasing in intensity throughout diastole, as described in the 2008 guidelines for the management of patients with valvular heart disease 1. The murmur is best heard at the left upper sternal border (second left intercostal space) and is usually accentuated during inspiration due to increased right-sided blood flow (Carvallo's sign). Some key characteristics of the murmur associated with pulmonic regurgitation include:
- A low to medium pitched sound in the absence of pulmonary hypertension, with a slightly delayed onset because regurgitant flow is minimal at pulmonic valve closure 1
- A high-pitched sound in the presence of pulmonary hypertension, which may be louder and harsher (Graham Steell murmur)
- A decrescendo pattern, consistent with the rapid decline in volume or rate of regurgitation during diastole When examining a patient with suspected pulmonic regurgitation, having them lean forward and hold their breath after expiration can help to better appreciate the murmur. Associated findings may include right ventricular heave, elevated jugular venous pressure, and peripheral edema if right heart failure develops. The murmur can be distinguished from aortic regurgitation by its location, respiratory variation, and associated findings of right heart disease, as noted in the guidelines for the management of adults with congenital heart disease 1. It is essential to consider the potential for pulmonary regurgitation in patients with a history of congenital heart disease or those who have undergone surgical or balloon valvuloplasty, as highlighted in the 2008 focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease 1.
From the Research
Characteristics of the Murmur Associated with Pulmonic Regurgitation
- The murmur associated with pulmonic regurgitation is typically a mid-frequency diastolic decrescendo murmur 2
- This murmur begins after the pulmonic component of the second heart sound 2
- In some cases, a right-sided Austin Flint murmur may be present, characterized by mid-diastolic and presystolic murmurs maximally in the outflow tract of the right ventricle 3
- The loudness of the diastolic murmurs may increase with inspiration 3
- The characteristics of the murmur can vary depending on the underlying cause and severity of the pulmonic regurgitation, as well as the presence of other cardiac abnormalities 4, 5, 6
Factors Influencing the Murmur
- Valvular integrity: The amount of pulmonic regurgitation is influenced by the integrity of the pulmonary valve 6
- Right ventricular size: The size of the right ventricle can affect the amount of regurgitation and the characteristics of the murmur 6
- Right ventricular diastolic pressures: Elevated diastolic pressures in the right ventricle can contribute to the development of the murmur 6
- Pulmonary artery pressures: The pressure in the pulmonary artery can also influence the characteristics of the murmur, with elevated pressures potentially leading to a louder or more prominent murmur 3, 6