[Reversible left ventricular hypertrophy and congestive heart failure due to suspected myocarditis in a cat in the course of FLUTD].

Sinzinger, Sonja

A 2.5-year-old castrated male domestic shorthair cat with a past pertinent history of FLUTD treatment 8 days earlier was presented during the night due to apathy and anorexia. Radiographs, ECG, blood pressure measurement and echocardiography revealed left-sided congestive heart failure, left ventricular concentric hypertrophy, left atrial dilation, severe diastolic dysfunction, hypotension, and vagotonus-associated sinus bradycardia with a first degree AV-block as well as a right bundle brunch block. NT-ProBNP and troponin I concentrations were elevated (NT-ProBNP > 1500 pmol/l, Troponin I 32.87 ng/ml). Presumptive diagnosis was acute myocarditis. Bartonella henselae PCR and Toxoplasma gondii IgM titer were negative. Initial IgG titer amounted to 1:32 (reference range: < 1:32) and on later testing this was negative. FeLV and FIV tests exhibited negative results. Coronavirus testing was not performed because the cat was vaccinated accordingly. A metastatic infection with Proteus mirabilis, which had been isolated from the urine, appeared possible. Alternatively, a hypersensivity reaction to drugs or a stress-induced myocarditis was taken into consideration. The hospitalized cat was treated with furosemide (initialy and in the course of further treatment), theophyllin (initially), continuous infusion with lactated Ringer's solution, pimobendan, and the addition of enrofloxacin to the ongoing amoxicillin/clavulanic acid administration. After 4 days, the cat's general condition improved satisfactorily and blood pressure returned to normal range. Left ventricular hypertrophy resolved, however, diastolic dysfunction as well as left atrial dilation persisted. Within the next 8 weeks, echocardiographic findings and cardiac biomarkers returned to near normal values. All medication was tapered and finally discontinued. During the last recheck examination 7 months following initial presentation, no cardiac changes were apparent.