A 30 Year Old Woman Presents With Increasing Shortness Of Breath

A 30-year-old woman presented to her family physician with increasing shortness of breath over the past 2 weeks. Prior to this, she had a flu-like illness and felt like she never recovered. She denied chest pain and edema, did not take any medications, and had not had any recent trauma or surgery. She had a normal examination. Her chest radiograph showed a classic globular heart as demonstrated in the picture above.  She had nonspecific ST changes on her ECG. An echocardiogram
confirmed pericardial effusion. The underlying etiology was not elucidated and she recovered spontaneously over the next several months.

Case Discussion
Pericardial Effusion:
Pericardial effusions are commonly found in the general population and the incidence increases with age.
Causes: It can be caused by :

• cardiac disease or surgery, 
• connective tissue disorders, 
• neoplasms, 
• infections,
• renal disease, 
• hypothyroidism, or 
• medications; 

The cause is however identified only 50% of the time. 

Pathophysiology: Pericardial effusion, acute or chronic, occurs when there is increased production or decreased drainage of pericardial fluid allowing accumulation in the pericardial space.

Clinical features: Signs and symptoms occur when the volume of fluid is large enough to affect hemodynamics. This occurs at 150 to 200 mL in acute pericardial effusion. Chronic pericardial effusion allows stretching overtime and may require up to 2 L to cause significant symptoms. The symptoms may include:

• Hypotension, increased jugular venous pressure, and soft heart sounds form the classic triad of acute cardiac tamponade, but all three are present only in approximately 30% of cases
• Common symptoms include anorexia (90%), dyspnea (78%), cough (47%), and chest pain (27%).
• Common physical examination findings include:

1. Pulsus paradoxus
2. Sinus tachycardia 
3. Jugular venous distention ,
4. Hepatomegaly and P
5. Peripheral edema 

Diagnosis: Clinical features, chest radiograph, and electrocardiogram suggest pericardial effusion, which is confirmed by echocardiogram.
1. Electrocardiogram is abnormal in 90%. Findings include low QRS voltage and nonspecific ST-T changes and electrical alternans.
2. Pericardial fluid analysis: When the diagnosis remains unclear, pericardial fluid can be sent for cell count and differential, protein, lactate dehydrogenase, glucose, Gram stain, bacterial cultures, fungal cultures, mycobacterial acid-fast stain and culture, and tumor cytology.
3. Chest radiograph shows a globular enlarged cardiac silhouett with moderate or severe effusions
4. Echocardiography is the preferred imaging test. Echo can be used to quantify volume of pericardial effusion.
5. CT scanning, typically done for another purpose, can demonstrate the presence of a pericardial effusion, but does not qualify volume.
6. Blood tests for antinuclear antibody (ANA) and thyroid-stimulating hormone (TSH).

Treatment:
Treat any identified underlying cause.
• When the diagnosis is unclear and the patient is hemodynamically stable, NSAIDs may be beneficial, especially if inflammatory markers are elevated.
• Pericardiocentesis is required when there is hemodynamic compromise. A pericardiocentesis is also useful when the pericardial effusion is large or suspected to be secondary to a bacterial infection or neoplastic process.
• Pericardiocentesis is performed by a specialist under local anesthesia.