Epidemiological and clinical features of the endomyocardial form of restrictive cardiomyopathy in cats: a review of 41 cases

Abstract

Examination of our necropsy records for the period 2005 to 2014 yielded 41 cases of the endomyocardial form of restrictive cardiomyopathy among 327 cats with evidence of heart disease, and here, we reviewed their epidemiological and clinical features. The medical data obtained retrospectively included signalment, presenting complaints, findings of physical examination, results of various diagnostic tests, methods of treatment and survival times. Except for one Chinchilla Persian cat, all were domestic short-haired cats. The mean age at death was 7.3 ± 4.5 years (median, 6 years; range, 4 months to 19 years), and males accounted for 61% (25/41) of the total. Dyspnea was the most common clinical sign, being evident in 83% (35/41) of the cats. Hind limb paresis or paralysis due to aortic thromboembolism was evident in 41% (17/41). Arrhythmias of atrial origin were common. Echocardiography commonly revealed left atrial or biatrial enlargement with severe endocardial thickening of the left ventricle. Most of the affected cats had a poor outcome; the disease duration ranged from 1 to 977 days, and the median survival period was 30 days.

Clinical, epidemiological and echocardiographic features and prognostic factors in cats with restrictive cardiomyopathy: A retrospective study of 92 cases (2001‐2015)

“…Most cats (70%) included in our study had at least 1 clinical sign related to RCM at the time of diagnosis, with a clear predominance of CHF signs detected in 94% of these cats. These results are in accordance with those of other reports, showing that most cats with RCM show clinical signs at the time of diagnosis, predominantly related to CHF . This high proportion of cats with CHF may be related, at least in part, to the chosen diagnostic criteria of RCM: all RCM cats in our study had to present with LA enlargement (which was considered severe in 24% of cases and associated with RA enlargement in >33% of cases).…”

“…Most cats with RCM in our study were middle‐aged animals (median age, 8.6 years), as reported by others (mean or median age from 6 to 10 years) . Nevertheless, like RCM cats in previous studies, the age range was wide, thus highlighting the presence of RCM in very young (<1 year old) but also in very old (>15 years old) cats, similar to the most common cardiomyopathy of cats (HCM) …”

“…Previous reports have provided relevant information on clinical, echocardiographic, and pathological features of RCM in cats . Survival times also have been reported in several studies . Our study provides additional information, particularly regarding the effects of epidemiological, clinical, and echocardiographic variables on prognosis in a large population of cats with RCM.…”

“…Previous reports have provided relevant information on clinical, echocardiographic, and pathological features of RCM in cats . Survival times also have been reported in several studies .…”

“…Spontaneously occurring RCM also has been reported in cats . Two different histopathological forms of RCM in cats have been described (ie, the “myocardial” form characterized by patchy to diffuse interstitial myocardial fibrosis and, less commonly, the “endomyocardial fibrosis” form [EMF]) .…”