Page 145 - Problem-Based Feline Medicine

9 – THE CAT WITH ABNORMAL HEART SOUNDS AND/OR AN ENLARGED HEART 137

– Enalapril 0.5 mg/kg PO q 24 h OR ● Anti-thrombotic therapy:
– Benazepril 0.5 mg/kg PO q 24 h. – Heparin and Warfarin therapy are controver-
sial and should be utilized under the guidance of
Symptomatic cat with congestive heart failure (acute
an experienced clinician.
management). Criteria to start therapy:
– Low-molecular-weight heparins have been
● Respiratory distress (open-mouth breathing or very
recently suggested. This class of heparins does
abnormal respiratory pattern).
not require continued monitoring of coagulation
● Pulmonary congestion (moderate to severe) on radi-
parameters.
ographs and/or pleural effusion.
– Enoxaparin (Lovenox ®) 1 mg/kg SQ q 24 h.
● Hypothermia.
– Aspirin 80 mg PO q 48–72 h is recommended by
● Oxygen.
some clinicians but its efficacy has not been estab-
● Diuretics. *
lished. A lower dose (5 mg/cat PO q 24 h) has
– Furosemide 1–2 mg/kg IV or IM q 8–12 h until
also been recommended, because of concerns of
respiratory rate and pattern are normalized.
that prostacyclin production is inhibited at the
– Furosemide constant rate infusion (if normal renal
higher dose.
values at presentation) 0.5–1 mg/kg/hr until con-
Thrombolytic therapy is contraindicated if an intracar-
gestion is resolved but not for longer than 24 hours.
diac thrombus is present, and controversial in aortic
● Venodilator.
saddle thrombus (see page 916, The Weak and Ataxic
– Nitroglycerin ointment (2%) 1/4 of an inch
or Paralyzed Cat).
(6 mm) q 8 h.
● Thoracocentesis (right thorax to avoid puncturing
of the enlarged auricles) if there is evidence of mod- Prognosis
erate to severe pleural effusion on radiographs.
Almost all cats after development of congestive heart
● Angiotensin-converting enzyme inhibitor.
failure have a poor prognosis.
– Enalapril 0.25–0.5 mg/kg PO q 24 h OR
– Benazepril 0.25–0.5 mg/kg PO q 24 h. It is unknown if early therapy of asymptomatic cats
results in delay of onset of clinical signs.
Symptomatic cat with congestive heart failure (chronic
management). Criteria to start therapy:
● Maintenance therapy after initial therapy to control NEOPLASIA**
signs of acute congestive heart failure.
● Any patient found to have early evidence of con- Classical signs
gestive heart failure (usually on radiographs) but
● Anorexia.
without symptoms, that will require acute inter-
● Weight loss.
vention if untreated.
● Diuretics *
– Furosemide 0.5–1.0 mg/kg PO q 12–24 h OR
Clinical signs
– Hydrochlorothiazide 1–2 mg/kg PO q 12 h
OR/AND Cats commonly present with anorexia and secondary
– Spironolactone 2–4 mg/kg PO q 12 h. weight loss.
● Angiotensin-converting enzyme inhibitor
A cranial mediastinal mass may cause a non-compli-
– Enalapril 0.25–0.5 mg/kg PO q 24 h OR
ant chest wall during compressive palpation.
– Benazepril 0.25–0.5 mg/kg PO q 24 h.
● Arrhythmia control The presence of intrathoracic or pericardial masses may
– Sotalol 15–30 mg/cat PO q 8 h OR cause effusions which will result in muffled heart
– Propranolol 0.5–1.0 mg/kg PO q 8 h OR sounds or displaced lung and/or heart sounds.
– Atenolol 12.5 mg/cat PO q 12–24 h OR
If a mass compresses the heart, a new murmur can result.
– Diltiazem 15 mg/cat PO q 8 h.
● Associated intracardiac thrombus or systemic Some cats with pericardial effusion secondary to neo-
thromboembolism. plasia present for the evaluation of ascites.