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Aortic Thromboembolism, Feline 75

Synonyms cyanotic and cool to the touch; may or may coexisting abdominal organ infarction,
Feline aortic thromboembolism (FATE), saddle not be visibly painful. particularly if the diagnosis is unclear or if
VetBooks.ir Epidemiology Etiology and Pathophysiology • Nonselective angiography: can confirm extent Diseases and Disorders
signs suggest visceral infarction.
thrombus, arterial thromboembolism
of vessel occlusion and associated visceral
• Thromboembolism is positively correlated
SPECIES, AGE, SEX
artery occlusion; rarely done.
blood stasis in the atrium as a predisposing
Feline, all ages of adults reported, male with increasing left atrial size, suggesting • Computed tomography/magnetic resonance
predisposition cause for thrombus formation. imaging: provides detailed information about
• Hypercoagulability exists in some cats with the extent of vascular occlusions but requires
GENETICS AND BREED PREDISPOSITION cardiomyopathy and atrial enlargement with general anesthesia, which is problematic in
None beyond predispositions for specific coexisting spontaneous echocardiographic these unstable patients; rarely done.
underlying heart diseases contrast, atrial thrombi, or an existing
thromboembolus but not in cats with left TREATMENT
RISK FACTORS atrial enlargement alone.
• Heart disease (hypertrophic cardiomyopathy, • Less common causes include primary tumor Treatment Overview
restrictive cardiomyopathy, unclassified emboli and sterile emboli related to pulmo- • Treatment is mainly supportive, including
cardiomyopathy, dilated cardiomyopathy, nary neoplasia. pain management; the efficacy of thrombo-
congenital cardiac disorders) lytic and antithrombotic/antiplatelet treat-
• Spontaneous contrast in the left atrium or DIAGNOSIS ments in the acute stage is not established.
left ventricle (echocardiographically) • Supportive care (pain control, maintain
• Pulmonary or other neoplasia Diagnostic Overview hydration, treat associated CHF [p. 408],
The diagnosis is generally apparent from the maintain electrolyte balance and renal
Clinical Presentation physical examination findings alone. perfusion, applying warm water bottles to
DISEASE FORMS/SUBTYPES hindlimbs)
• Saddle thrombus: total or partial occlusion Differential Diagnosis • Clot dissolution: the goal of thrombolytic
of the distal aortic trifurcation • Trauma (pelvic fractures, femoral fractures, therapy is attempted (tissue plasminogen
• Brachial artery embolus (single forelimb spinal injury) activator, streptokinase). Rarely attempted,
affected) • Primary neurologic disease (spinal infarction, but best performed by experienced specialist
• Visceral artery thromboembolism (renal intervertebral disc disease, spinal neoplasia, as soon as possible.
artery, mesenteric artery): less common, may trauma) • Preventing extension of the thromboembolus:
accompany saddle thrombus • Severe systemic hypotension antithrombotic and antiplatelet therapy
• Prevention of additional thromboembolic
HISTORY, CHIEF COMPLAINT Initial Database episodes
• History of heart disease or physical exam • CBC, biochemical profile, urinalysis: com-
findings of cardiac disease (murmur, arrhyth- monly noted abnormalities include hypergly- Acute General Treatment
mia) is common. cemia, elevations in alanine aminotransferase • Pain management (hydromorphone 0.1-
○ A pre-existing heart murmur is less com- (ALT) and aspartate aminotransferase (AST), 0.2 mg/kg SQ or IV q 4-8h, or morphine
monly noted in the history of cats with hypocalcemia, and various degrees of azote- 0.05-0.2 mg/kg SQ q 6-8h, or buprenor-
restrictive and unclassified cardiomyopathy. mia (suggests concomitant renal infarction) phine 0.01-0.015 mg/kg SQ or IV q 6-12h,
• Saddle thrombus: peracute onset of pain and • Thyroid hormone analysis (if ≥ 6 years old) or butorphanol 0.1-0.4 mg/kg SQ or IV q
paresis/paralysis of hindlimbs • Feline leukemia, feline immunodeficiency 2-4h)
• Brachial artery thrombus: sudden onset of serology (if at risk for these diseases; not a • Diuretics, if CHF present (furosemide
lameness or disuse of a forelimb, may or direct contributor to FATE) 1-4 mg/kg SQ or IV q 4-12h)
may not be painful • Full coagulation profile (prothrombin time • Vasodilators: if blood pressure is adequate,
• Visceral thromboemboli: acute onset [PT], activated partial thromboplastin time may help collateral circulation in the hind
abdominal pain, vomiting, and lethargy [aPTT], and platelet count) legs (hydralazine 0.5-1 mg/kg PO q 12h,
○ Decreased PT and/or aPTT: no correlation acepromazine 0.025-0.05 mg/kg SQ q
PHYSICAL EXAM FINDINGS with whether a cat is in a procoagulant 12-24h); angiotensin-converting enzyme
Saddle thrombus: state but often useful as baseline for inhibitors (enalapril, benazepril) usually
• Pain (often appears excruciating, with monitoring therapy. avoided in the acute setting due to potential
vocalization and panting) and varying degrees • Full-body radiographs coexisting renal infarctions
of paralysis of the hindlimbs ○ Thorax: signs of congestive heart failure • Oxygen therapy (p. 1146): if CHF, dyspnea
• Typically absence of femoral pulses (pulmonary edema, pleural effusion), • Fluid therapy: conservative crystalloid therapy
○ Incomplete forms may have unilateral loss signs of cardiac disease (cardiac chamber is typically administered in patients in the
of femoral pulse or a differential in the enlargement), evidence of pulmonary absence of fulminant CHF.
femoral pulse strength. neoplasia
• Firm, painful quadriceps and gastrocnemius ○ Spine: fractures, neoplasia (differential Chronic Treatment
musculature diagnosis) • Aimed at treatment for the underlying
• Hypothermia (via rectal thermometer) is • Echocardiography (once stable) to diagnose condition (treatment of heart disease, removal
common. associated cardiac disease, evaluate for of primary lung tumor) and prevention of
• Footpads are cyanotic and cool to the touch; intracardiac thrombi, and spontaneous repeated thromboembolic episodes
nail beds are cyanotic. echocardiographic contrast (p. 1094) • Anticoagulant therapy
• Dyspnea is common; diagnostic testing must • Electrocardiography (once stable) (p. 1096) ○ Rivaroxaban 2.5 mg/CAT PO q 24h is being
distinguish between pain and congestive heart • Blood pressure determinations (p. 1065) evaluated as an alternative to clopidogrel
failure (CHF) as the cause. 18.75 mg/CAT PO q 24h for prevention
Brachial artery embolus: various degrees of Advanced or Confirmatory Testing of recurrent episodes of FATE or
forelimb paralysis (typically paw knuckled • Abdominal ultrasound: may be helpful in ○ Warfarin 0.25 mL of 1 mg/mL suspension
under); absence of brachial pulse, footpad identifying extent of vessel occlusion and initially administered per cat q 24h, dose

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