Arrhythmogenic cardiomyopathy in a cat

Cardiomiopatia arritimogênica em um gato

Arrhythmogenic cardiomyopathy is a rare cardiac disease in cats, characterized by ventricular myocyte atrophy and replacement by fibrofatty tissue, predisposing to potentially fatal arrhythmias and heart failure. This report described a 12-year-old mixed-breed male cat with recurrent episodes of syncope, manifested by sudden weakness and altered consciousness. Physical examination revealed hypothermia, hypotension, and an irregular cardiac rhythm. Diagnostic evaluations confirmed chronic kidney disease and cardiomegaly, with echocardiographic findings compatible with arrhythmogenic cardiomyopathy. Despite treatment with pimobendan and clopidogrel, the heart failure progressed, culminating in refractory hypotension and the need for hospitalization. The hemodynamic instability and lack of response to therapy indicated a poor prognosis and led to the decision for euthanasia. Postmortem histopathological analysis confirmed the presence of biventricular arrhythmogenic cardiomyopathy. This case highlighted the importance of early diagnosis of feline arrhythmogenic cardiomyopathy, as advanced stages often follow a refractory course despite therapeutic interventions. Histopathological confirmation remains essential, particularly in atypical clinical presentations such as recurrent syncope in patients without overt signs of congestive heart failure.

Key words:
cardiac arrhythmia; cardiomyopathy; cats; heart failure; syncope