Graham Steell murmur

Graham Steell murmur is a distinctive heart murmur associated with pulmonary hypertension. It is named after the British physician Graham Steell, who first described it in 1888. This murmur is indicative of pulmonary regurgitation, a condition where blood flows backward into the right ventricle of the heart due to elevated pressure in the pulmonary artery. The Graham Steell murmur is considered a sign of advanced pulmonary arterial hypertension (PAH) and is most commonly heard in patients with untreated or advanced stages of the disease.

Characteristics

The Graham Steell murmur is a high-pitched, decrescendo diastolic murmur heard best at the left upper sternal border. It occurs immediately after the second heart sound (S2) and is best heard with the diaphragm of the stethoscope. The presence and severity of the murmur correlate with the degree of pulmonary hypertension and the extent of pulmonary regurgitation. The murmur's pitch and duration can increase with activities that elevate pulmonary artery pressure, such as exercise.

Pathophysiology

Pulmonary hypertension leads to increased pressure in the pulmonary artery, which can eventually overwhelm the pulmonary valve's ability to close properly. This results in pulmonary regurgitation, where blood leaks back into the right ventricle during diastole. The regurgitant flow creates the characteristic sound of the Graham Steell murmur. Over time, sustained pulmonary hypertension can cause right ventricular hypertrophy and heart failure.

Diagnosis

Diagnosis of the Graham Steell murmur is primarily clinical, based on the murmur's characteristic sound and timing. However, further investigations are necessary to confirm the presence of pulmonary hypertension and to assess its severity. These may include:

• Echocardiography: An ultrasound of the heart that can visualize the regurgitant flow through the pulmonary valve and estimate pulmonary artery pressures.
• Cardiac MRI: Provides detailed images of the heart's structure and function, including the right ventricle and pulmonary artery.
• Right heart catheterization: The gold standard for measuring pulmonary artery pressures and diagnosing pulmonary hypertension.

Treatment

Treatment of the Graham Steell murmur focuses on addressing the underlying cause of pulmonary hypertension. Therapeutic strategies may include:

• Medications: Various drugs can lower pulmonary artery pressure, improve symptoms, and slow the progression of pulmonary hypertension. These include endothelin receptor antagonists, phosphodiesterase-5 inhibitors, and prostacyclin analogs.
• Oxygen therapy: For patients with hypoxemia, supplemental oxygen can help reduce pulmonary artery pressures.
• Lifestyle modifications: Weight loss, exercise, and dietary changes can improve symptoms and quality of life in patients with pulmonary hypertension.
• Surgical interventions: In severe cases, procedures such as lung transplantation or creation of a shunt (atrial septostomy) may be considered.

Prognosis

The prognosis for patients with a Graham Steell murmur depends on the underlying cause and severity of pulmonary hypertension. Early diagnosis and treatment can improve outcomes and quality of life. However, advanced pulmonary hypertension can lead to right heart failure and is associated with a poorer prognosis.