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Pericardial Effusion

Issue Description
Pericardial effusion is the abnormal accumulation of fluid in the sac around the heart. As the fluid volume and intrapericardial pressure increase, cardiac tamponade can develop. The most common causes of pericardial effusion include cardiac hemangiosarcoma, idiopathic pericardial effusion, and chemodectoma. Understanding the underlying cause is important in providing treatment recommendations and an accurate prognosis.
Other Names

Causes of pericardial effusion include:
  • Neoplasia
  • Right atrial hemangiosarcoma
  • Heart base (aortic body, ectopic thyroid) tumors
  • Mesothelioma
  • Lymphosarcoma
  • Idiopathic
  • Congestive heart failure
  • Peritoneopericardial diaphragmatic hernia
  • Pericardial cysts (seen in younger dogs, usually are caudoventral)
  • Hypoalbuminemia
  • Pericarditis (Bacterial from foxtail perforation, fungal from Coccidioides immitus, cholesterol-based secondary to hypothyroidism)
  • Left atrial tear secondary to valvular disease
  • Coagulopathy

  • Symptoms
    Signs of pericardial effusion can include lethargy, exercise intolerance, anorexia, dyspnea, abdominal distension and syncope. Physical exam findings may include jugular venous distension, muffled heart sounds, hepatomegaly, ascites, weak pulses and pulsus paradoxus. Usually there is no heart murmur present. Thoracic radiographs may show an enlarged, globoid cardiac silhouette, and pleural effusion is seen more commonly than pulmonary edema. Routine bloodwork findings are frequently normal. The classic ECG abnormality is electrical alternans, which is a beat-to-beat variation of the ECG, usually of the QRS complex. The variation usually occurs every other beat due to the undulating motion of the heart. This condition tends to occur most commonly in middle-aged to older large breed dogs.

    Echocardiography is the most sensitive and specific, noninvasive method of detecting pericardial effusion. Often dogs with pericardial effusion present with ascites, and an abdominal ultrasound may be initially done. Ascites, hepatomegaly, and hepatic venous distension may be seen in the abdomen, and the presence of these findings suggests that an echocardiogram should be done.

    Treatment of pericardial effusion typically begins with pericardiocentesis. Surgical or thoracoscopic pericardiectomy and percutaneous balloon pericardiotomy are procedures performed to treat recurrent pericardial effusion.

    The prognosis varies greatly, depending on the underlying cause.

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