Case Study

Hypertrophic cardiomyopathy in an 11 year old MN DSH with sudden-onset hind limb paralysis

An 11-year-old MN DSH cat presented for sudden onset of hind limb paralysis. CBC and blood chemistry were both within normal limits. Blood pressure measurements were within normal range. MRI revealed lesions suspect for fibrocartilaginous embolism at L6 through the sacrum. Thoracic radiographs showed mild cardiomegaly and a valentine-shaped heart.

Sonographic Differential Diagnosis

Hypertrophic cardiomyopathy with left atrial enlargement.

Image Interpretation

The echocardiogram in this patient demonstrated a thickened left atrium. The cranial and caudal mitral valve leaflets presented normal linear structure, extension in systole, and union in diastole. The mitral insufficiency velocity measured 7.9 m/sec. Systolic anterior motion was noted, which caused dynamic obstruction. The left ventricle presented excessive free wall and septal thicknesses with hypertrophic contour. The chamber was somewhat restricted. Septal deviation was noted impinging into the left ventricular outflow tract. Contractility of the ventricular walls was considered excessive for this patient evidenced by the fractional shortening measurement. The left ventricular outflow tract demonstrated turbulent laminar flow without evidence of hemodynamically significant insufficiency; however, excessive outflow velocity was present. Mild tricuspid insufficiency was noted. The tricuspid insufficiency velocity was 1.5 m/sec.

DX

Hypertrophic cardiomyopathy with left atrial enlargement.

Clinical Differential Diagnosis

Cardiomyopathy (dilated/hypertrophic/restrictive) with thromboembolism

Sampling

Recheck blood pressure measurements, ECG, and treatment with atenolol, enalapril, and aspirin were recommended for this patient. A recheck of the patient’s renal values was advised in one week. Physical examination four weeks after original presentation found the patient clinically improved and ambulatory on all four limbs.