Recurrent transient myocardial thickening and congestive heart failure in a cat.

A five-year-old female spayed domestic shorthair cat presented for acute onset respiratory distress. Thoracic radiographs and echocardiography revealed left-sided congestive heart failure and left ventricular thickening with left atrial dilation, respectively. The cat was treated with furosemide, clopidogrel, and ondansetron. Re-evaluation one year later revealed complete reverse remodeling with normalization of the left ventricle and left atrial size on echocardiography. Medical therapy was discontinued. Approximately two years after the initial presentation, the cat presented again for acute onset respiratory distress. Thoracic radiographs and echocardiography again revealed left-sided congestive heart failure and left atrial dilation, with thickening of the interventricular septum and left ventricular posterior wall. Cardiac troponin I was elevated and progressively increased over the first 24 hours, then decreased and ultimately normalized following treatment with furosemide, clindamycin, enrofloxacin, doxycycline, and clopidogrel. Infectious disease testing did not reveal an underlying cause. Re-evaluation one year later again revealed cardiac normalization on echocardiography. Here, we report a case of recurrent transient myocardial thickening in a cat.