Page 161 - Problem-Based Feline Medicine

9 – THE CAT WITH ABNORMAL HEART SOUNDS AND/OR AN ENLARGED HEART 153

Inotropic Support Prevention
● Digoxin 0.016 mg/cat PO q 24–48 h (monitor for
Cats should be maintained on a diet designed for the
anorexia and gastrointestinal signs). OR
feline patient, which has adequate amounts of taurine.
– For monitoring, obtain a serum sample 8 hours
after giving digoxin dose. Do not store the serum
in plastic tubes, since digoxin binds to plastic. PERITONEAL–PERICARDIAL
Therapeutic serum concentrations range from DIAPHRAGMATIC HERNIA (PPDH)
1.3–3.2 nmol/L (1.0–2.5 ng/ml). The authors pre-
fer not to exceed levels higher than 1.9 nmol/L Classical signs
(1.5 ng/ml). The side effects usually are GI signs
● Vomiting.
and anorexia.
● Diarrhea.
● Pimobendan 0.25 mg/kg PO q 12 h.
● Weight loss.
● Arrhythmia control.
● Dyspnea.
– Improvement is usually seen with supportive
treatment.
– Caution should be exercised if beta-blockers or Pathogenesis
calcium channel blockers are used, due to the
Persistent communication occurs between the peri-
negative inotropic effects of these drugs.
cardial and peritoneal cavities because of abnormal
– For ventricular or supraventricular arrhythmias:
fusion of the septum transversum with the pleuroperi-
– Procainamide SR 10–20 mg/kg PO q 8 h.
toneal folds during development.
– Associated intracardiac thrombus or systemic
thromboembolism. The hernia is of variable size.
● Anti-thrombotic therapy: The most likely organs to be herniated are the liver and
– Heparin and Warfarin therapy are controver- gallbladder, small intestine, spleen, stomach.
sial and should be utilized under the guidance of
an experienced clinician.
Clinical signs
– Low-molecular-weight heparins have been
recently suggested. This class of heparins does Signs are mostly related to the gastrointestinal system
not require continued monitoring of coagulation and include vomiting, diarrhea and weight loss.
parameters.
Most cases are asymptomatic and it is an incidental
– Enoxaparin (Lovenox ®) 1 mg/kg SQ q 24 h.
finding. An increased incidence in Persian cats is sus-
– Aspirin 80 mg PO q 48–72 h is recommended by
pected.
some clinicians but its efficacy has not been estab-
lished. A lower dose (5 mg/cat PO q 24 h) has Physical exam is often normal. In some cases, the heart
also been recommended, because of concerns that sounds may be muffled.
prostacyclin production is inhibited at the higher
In symptomatic patients, respiratory signs can be pres-
dose.
ent, particularly under stressful conditions.
Thrombolytic therapy is contraindicated if an intracar-
diac thrombus is present, and controversial in aortic
Diagnosis
saddle thrombus.
Radiographic findings
Prognosis Extreme enlargement of the “cardiac” silhouette.

Prognosis is good if the etiology is taurine deficiency. Dorsal displacement of the trachea.
Most cases currently seen are not due to taurine defi- Silhouetting of the caudal border of the heart with the
ciency and the prognosis is poor. diaphragm.