Hypertrophic Cardiomyopathy in an Aged Dog

Abstract

A 14-year-old female Yorkshire terrier was presented with the complaint of cardiac murmur and convulsive seizure. Thickened mitral valve, left atrial enlargement, excess motions of the left ventricular (LV) free wall and the ventricular septum, and tricuspid, mitral and aortic valve regurgitations were recognized on echocardiography. Follow-up echocardiography revealed the progression of concentric LV hypertrophy and LV outflow obstruction. Clinical symptoms associated with cardiac failure did not develop during the observation period. The pathological examination of the heart revealed that the dog had the morphological hallmarks of hypertrophic cardiomyopathy: massive ventricular hypertrophy, disorganization of cardiac muscle cells, interstitial myocardial fibrosis, and abnormal intramural coronary arteries.

Hypertrophic cardiomyopathy secondary to severe right and left ventricular outflow tract obstruction in a Maltese dog

“…There were degenerative changes in mitral valvular cusps, probably by aging process. There were evidence of infarction and early abscessation possibly from chronic HCM, or embolus formation resulting in blood vessel occlusion and downstream ischemic degeneration and necrosis of the affected cardiac tissue as similarly noticed in other case [7]. However, there was no evidence for infection or neoplasia.…”

“…Primary HCM is mostly occurred by genetic defects in proteins consisting of cardiac sarcomere in cats and humans [1,5]. Secondary HCM can be occurred by abnormally thickened intramural coronary arteries, subendocardial ischemia, and other cardiac structural abnormalities including stenosis in ventricular outflow tract [2,[5][6][7]. This case report described a rare case of HCM secondary to severe right and left ventricular outflow tract obstruction in a dog.…”

Canine dynamic left ventricular outflow tract obstruction: assessment of myocardial function and clinical outcome

“…HCM is frequently described as a cause for DLVOTO in human beings and cats, but this has been reported infrequently in dogs (Thomas 1984, Liu and others 1993, Marks 1993, Washizu and others 2003). The majority of historically reported HCM cases in dogs have a fatal outcome (Liu and others 1979, Sisson and others 1999, Pang and others 2005), but a recent report of patients with DLVOTO suggested a benign outcome (Connolly and Boswood 2003).…”

Genetics of feline hypertrophic cardiomyopathy

“…Although there are anecdotical reports in the literature of other animal species with clinical signs of HCM (dogs, rodents, cattle, camels, monkeys and pigs), the only known animal presenting with this disease spontaneously, frequently and with a familial component is the cat 10‐14 …”