Welcome to episode 93 of the Audio PANCE and PANRE physician assistant/associate board review podcast.
Today is part three of this extraordinary five-part series with Joe Gilboy PA-C, all about cardiac murmurs. In this week's episode of the Audio PANCE and PANRE podcast, we continue our discussion of cardiac murmurs with a focus on the pulmonic valve.
We'll talk about the different types of murmurs (stenosis and regurgitation) that can occur with the pulmonic valve and how to differentiate them from other types of murmurs. If you haven't already, make sure to listen to our previous podcast episode where we covered the aortic valve murmurs and mitral valve murmurs.
The Pulmonic Valve
Pulmonic valve stenosis (PVS) and pulmonic valve regurgitation (PVR) are two common heart valve diseases. PVS is a narrowing of the pulmonic valve, while PVR is leakage of blood back through the pulmonic valve. Both conditions can lead to significant heart problems if left untreated.
Pulmonic valve stenosis
PVS is the most common congenital heart disease, affecting approximately 1 in 1000 people. It can lead to right heart failure and/or pulmonary hypertension (high blood pressure in the lung arteries). PVS is caused by an abnormally thickened pulmonic valve or localized stenosis which means that it has a narrowing of the valve. Pulmonic valve stenosis has several different causes including:
Congenital heart disease – this means that the abnormal valve was present from birth but is often undiagnosed until adulthood. For example, children with Down's syndrome or Noonan syndrome are more likely to have an undiagnosed congenital heart defect such as PVS. It commonly is a component of tetralogy of Fallot.Cocaine use in pregnancy – research has shown that there is a link between the use of cocaine in pregnant women and children with PVS, particularly if it is used close to the time of conception or later stages of pregnancy.Infection during pregnancy can cause an inflammatory response which may lead to heart problems for the baby.Autoimmune disease – PVS is sometimes associated with other autoimmune diseases, such as lupus.
Symptoms of PVS can vary depending on the type of stenosis that is present and how much it has advanced. Mild cases may not cause any symptoms at all; however, it is common for patients to experience breathlessness, fatigue, chest pain, and palpitations.
Heart sounds include increased splitting of S2 and a harsh crescendo-decrescendo ejection murmur heard best at the left parasternal 2nd or 4th intercostal space when the patient leans forward; the murmur grows louder immediately with Valsalva release and with inspiration.
People with PVS may need to take some medication to ease their symptoms. For example, diuretics can help remove excess fluid; beta-blockers reduce the workload on the heart and therefore lower blood pressure and heart rate, and long-acting calcium channel blockers can reduce the force of contraction of the heart's left ventricle.
Pulmonary valve replacement is an effective treatment for severe PVS, which involves surgically implanting a new pulmonary valve to replace the defective one. Because the valve only affects the blood flow through one part of the heart, this surgery can often be carried out using minimally invasive techniques.
For milder cases of PVS that do not cause symptoms then medication or exercise may be prescribed instead. Regular exercise helps to strengthen the left ventricle (the main pumping chamber) which is important for people with PVS. For more information, view our lesson on pulmonary stenosis.
Pulmonic valve regurgitation
Pulmonic valve regurgitation is leakage of blood back through the pulmonic valve.
It can lead to right-sided heart failure and/or pulmonary hypertension (high blood pressure in the lung arteries). This means that it has a leakage of the valve.
It can be caused by any condition that impairs cardiac function,