Ewart's sign

Ewart's sign is a clinical sign used in the diagnosis of pericardial effusion, which is the accumulation of fluid in the pericardium, the fibrous sac surrounding the heart. This medical sign is named after William Ewart, a British physician who first described it in the late 19th century. Ewart's sign is considered significant in the physical examination of patients suspected of having a pericardial effusion, particularly large ones that may lead to cardiac tamponade, a life-threatening condition.

Clinical Presentation

Ewart's sign is characterized by several physical findings on examination. These include:

• Dullness to percussion over the area of the left scapula, which is caused by the accumulation of fluid in the pericardial sac compressing the left lung and displacing it upwards.
• Bronchial breathing sounds heard over the area of dullness, which are typically higher-pitched and more "tubular" in quality compared to normal lung sounds.
• Egophony near the angle of the left scapula. Egophony is a specific type of lung sound that is heard when the patient is asked to vocalize the letter "E," which then sounds like "A" due to changes in the transmission of sound through the effusion.
• Decreased tactile fremitus over the area, which is due to the effusion dampening the transmission of vibrations from the voice through the chest wall.

Pathophysiology

The pathophysiology behind Ewart's sign involves the accumulation of fluid in the pericardial cavity. This fluid accumulation can be due to various causes, including infection, inflammation, cancer, and trauma. The increased volume of fluid within the pericardium exerts pressure on adjacent structures, notably the left lung and potentially the heart itself, leading to the physical findings associated with Ewart's sign.

Diagnostic Importance

Ewart's sign is an important diagnostic clue in the physical examination of patients with suspected pericardial effusion. However, it is not universally present in all cases of effusion and its absence does not rule out the condition. The sign is more commonly associated with large effusions. The diagnosis of pericardial effusion typically requires imaging studies, such as an echocardiogram, which can directly visualize the accumulation of fluid around the heart.

Treatment and Prognosis

The treatment of pericardial effusion depends on its cause and severity. Small, asymptomatic effusions may require no immediate treatment but should be monitored for changes. Larger effusions, especially those causing symptoms or signs of cardiac tamponade, may require urgent intervention to remove the fluid, such as pericardiocentesis. The prognosis of pericardial effusion varies widely depending on the underlying cause and the presence of complications like cardiac tamponade.

See Also

• Pericardium
• Pericardial effusion
• Cardiac tamponade
• Pericardiocentesis