Page 166 - Problem-Based Feline Medicine

158 PART 3 CAT WITH SIGNS OF HEART DISEASE

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METABOLIC
● Tachyarrhythmias (sinus tachycardia, supraventricular/atrial tachycardia, ventric-
ular premature beats and ventricular tachycardia)*** (p 160)
Tachyarrhythmias can result from hyperthyroidism, acidosis and uremia or be drug-induced.
Cats tolerate tachycardia better than other species. Syncope, lethargy and weakness are the most
common signs in addition to the sign of the underlying disease.
● Ventricular arrhythmias (ventricular premature beats, ventricular tachycardia)***
(p 164)
Ventricular arrhythmias may result from hyperthyroidism, acidosis, uremia or be drug-induced. In
addition to the signs related to the underlying disease, cats may present with lethargy, weakness,
anorexia and syncope.

● Atrial arrhythmias (supraventricular/atrial tachycardia, atrial fibrillation) (p 161)
Atrial arrhythmias may be seen in hyperthyroidism. In addition to the signs related to the underly-
ing disease, cats may present with lethargy, weakness and syncope.
NEOPLASTIC
● Ventricular arrhythmias (ventricular premature beats, ventricular tachycardia) (p 164)
Ventricular arrhythmias may be seen in primary or metastatic cardiac disease. Most patients do not
show clinical signs from the arrhythmia. Most of the clinical signs are related to the underlying
disease.
INFECTIOUS
● Ventricular arrhythmias (ventricular premature beats, ventricular tachycardia) (p 164)
Ventricular arrhythmias may be seen with bacterial infections (endocarditis, myocarditis) and viral
infections (myopericarditis). Fever, lethargy, anorexia and a new heart murmur are the most com-
mon clinical signs.
IDIOPATHIC
● Ventricular arrhythmias (ventricular premature beats, ventricular tachycardia)***
(p 164)
Ventricular arrhythmias are most commonly seen in cases of feline cardiomyopathies. The major-
ity of the cases do not have symptoms related to the arrhythmia. Periods of ventricular tachycardia
(rates above 300 bpm) may cause lethargy or syncope.
● Atrial fibrillation* (p 162)
Atrial fibrillation can be seen in end-stage cardiomyopathies when severe left atrial enlargement
is present. Clinical signs include worsening of heart failure, weakness or syncope. Signs related
to systemic thromboembolism (paresis/paralysis of hindlimbs) may be present.
● Supraventricular arrhythmias (supraventricular/atrial tachycardia, atrial fibrilla-
tion)** (p 161)
Atrial tachycardias, atrial premature beats and other forms of supraventricular tachycardias can
occur in cats with cardiomyopathies. The majority of the cases do not have symptoms related to
the arrhythmia. Periods of supraventricular tachycardia (rates above 300 bpm) may cause lethargy
or syncope.