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 Pericardial Effusion
Causes Causes of pericardial effusion include:
Right atrial hemangiosarcoma
Heart base (aortic body, ectopic thyroid) tumors
Congestive heart failure
Peritoneopericardial diaphragmatic hernia
Pericardial cysts (seen in younger dogs, usually are caudoventral)
Pericarditis (Bacterial from foxtail perforation, fungal from
Coccidioides immitus, cholesterol-based secondary to hypothyroidism)
Left atrial tear secondary to valvular disease
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
Diagnosis 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 Treatment of pericardial effusion typically
begins with pericardiocentesis. Surgical or thoracoscopic
pericardiectomy and percutaneous balloon pericardiotomy are procedures
performed to treat recurrent pericardial effusion.
Prognosis The prognosis varies greatly, depending on the