Congestive heart failure associated with a large transverse left ventricular moderator band in a cat

Cardiomyopathy associated with abnormal trabecular bands of tissue traversing one or both ventricles is reported rarely in cats. The case of a 9-year-old cat which presented in congestive heart failure is reported. Multiple cardiac abnormalities were found, including a large trabecular tissue bridge which bisected the left ventricle. Other findings included arrhythmia, thrombocytopaenia and raised serum creatine kinase. The cat was euthanased due to clinical deterioration. Necropsy findings included increased cardiac weight, the division of the left ventricle by a large trabecular band composed of connective tissue and cardiac myofibres consistent with a moderator band, nodular thickening of the mitral valve, left atrial dilation, and fibroplasia/fibrosis of the left ventricular myocardium associated with widespread myofibre necrosis due to infarction. Pathological findings in this case differ from previous reports of ventricular transverse bridging tissue in cats with cardiac disease.