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774.e2 Pericarditis

Pericarditis Client Education
Sheet
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GEOGRAPHY AND SEASONALITY
BASIC INFORMATION
Infectious pericarditis: Pathophysiologic evolution reflects secondary
cardiac tamponade or constrictive-effusive
Definition • C. immitis in the southwestern part of the pericarditis:
Inflammation of the parietal and visceral United States • As effusion accumulates, intrapericardial
layers of the pericardium causes fibrosis and • Grass awn migration in the western part of pressure rises.
fusion of the two layers, which leads to peri- the United States • Intrapericardial pressure may exceed intra-
cardial thickening and/or adherence to the cardiac diastolic pressures and impair cardiac
epicardium. This process may cause constric- ASSOCIATED DISORDERS filling.
tion or intrapericardial fluid formation and • PE • Stroke volume is reduced.
accumulation, which can ultimately progress • Constrictive-effusive pericarditis • Central venous pressure increases, and venous
to cardiac tamponade. Noninflammatory Clinical Presentation return to the right atrium is impaired.
processes may also lead to pericardial effusion • Increased venous pressure leads to pleural
(PE) and cardiac tamponade and include DISEASE FORMS/SUBTYPES effusion and ascites. Pleural effusion or
cardiac neoplasia, coagulopathies such as • Pericarditis can cause illness with (most ascites may be due to increased venous
rodenticide intoxication, and left atrial tears common [p. 773]) or without significant pressure or concurrent infection in those
(p. 773). PE accumulation. body cavities (cytologic exam differentiates
• Rate and magnitude of fluid accumula- idiopathic benign pericarditis from infectious
Synonyms tion determine the clinical signs related pericarditis).
Idiopathic benign/sterile pericarditis, infectious to PE.
pericarditis • Virulence of the infectious agent influences DIAGNOSIS
the clinical signs in infectious pericarditis.
Epidemiology Diagnostic Overview
SPECIES, AGE, SEX HISTORY, CHIEF COMPLAINT Pericarditis is suspected in an animal that is
• Dogs more than cats; no sex predisposition • Anorexia systemically ill (e.g., weight loss, lethargy) with
• Idiopathic benign pericarditis is the • Weight loss PE ± right heart failure (pleural effusion and/
second most common cause of PE in • Lethargy, weakness or ascites); pericardiocentesis with fluid and
the dog (neoplastic causes are most • Dyspnea cytologic analysis plus culture and susceptibility
common) • Acute collapse tests are required for confirmation of infectious
• Infectious pericarditis • Ascites pericarditis.
○ Infectious pericarditis is a rare cause of
PE in dogs and cats. PHYSICAL EXAM FINDINGS Differential Diagnosis
○ Dogs: the cause is identified in 2% of cases Reflects secondary cardiac tamponade or • Radiographic
diagnosed with infectious pericarditis and constrictive-effusive pericarditis: ○ Cardiac enlargement from other types of
PE. • Jugular vein distention or pulsation heart disease
○ Cats: the cause is identified in 14% of • Tachycardia ○ Peritoneopericardial diaphragmatic hernia
cases diagnosed with infectious pericarditis • Weak arterial pulses, pulsus paradoxus (p. 778)
and PE. (palpable variation of pulse strength with ○ Normal variation
respiration) • Echocardiographic
GENETICS, BREED PREDISPOSITION • Muffled heart and lung sounds ○ PE due to other causes (e.g., neoplastic,
Dogs: golden retriever, German shepherd, Saint • Ballotable abdominal fluid wave, hepato- coagulopathy [p. 1266])
Bernard, Great Pyrenees, bull mastiff, Lhasa jugular reflux ○ Pleural effusion: many causes (p. 1269)
apso, shih tzu • Pale mucous membranes
• Fever with infectious pericarditis (inconsistent Initial Database
RISK FACTORS finding) • CBC: if infective pericarditis, may see anemia,
Infectious pericarditis Other exam findings due to primary infection inflammatory leukogram, degenerative left
• Local infection (pleural or pulmonary) possible (e.g., uveitis, lymphadenopathy) shift
• Penetrating trauma • Serum biochemistry panel: elevated liver
• Migrating foreign body Etiology and Pathophysiology enzyme levels, elevated creatine kinase (CK)
• Open wounds Idiopathic benign PE (common): level, decreased albumin level possible
• Immunosuppression • Unknown cause • Thoracic radiographs: mildly to severely
• Bacteremia, viremia, or systemic fungal • Generally associated with accumulation of enlarged, round cardiac silhouette; caudal
disease hemorrhagic effusion composed of inflam- vena cava distention; pleural effusion ±
matory fluid from damaged blood vessels, abnormal pulmonary parenchyma
CONTAGION AND ZOONOSIS lymphatics, mesothelial cells, and micro- • Echocardiogram: PE, which may be anechoic
Infectious pericarditis: villi of the serosal layer of the pericardial or hyperechoic, ± thickened pericardium,
• Feline infectious peritonitis (FIP [p. 327]) sac fibrin, ± hyperechoic densities within
• Tuberculous pericarditis, although uncom- Infectious pericarditis (uncommon): pericardial space
mon, has been reported (postmortem risk for • Associated with multiple possible bacte- • Electrocardiogram (ECG): changes may
transmitting the disease from dog to human) rial, fungal, or viral infections resulting in be present if effusion is severe: low-voltage
(p. 670). inflammation, fibrosis, thickening of the complexes (50% of cases), electrical alternans
• Coccidioides immitis (postmortem risk for pericardium and epicarditis. Effusion may (25% of cases), ST-segment changes
transmitting the disease from dog to human) lead to PE and tamponade or constrictive • Abdominal ultrasound: screen for neoplasia
(p. 184) pericarditis. (e.g., hemangiosarcoma)

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