Case Study

Mild systolic anterior motion (SAM) of the mitral valve in a 19 year old MN DSH cat

A 19 year old neutered male DSH was presented for vomiting with a history of chronic renal failure and hypertrophic cardiomyopathy. A grade III/VI heart murmur was audible on auscultation. Urinalysis and CBC were both within normal limits. On serum biochemistry, an elevated AST activity, elevated BUN, elevated creatinine, and hypercalcemia were present. Average blood pressure was 185/125.

DX

Mild systolic anterior motion mitral valve

Sonographic Differential Diagnosis

Mild left ventricular hypertrophy. Rule out systemic hypertension, hyperthyroidism, pseudohypertrophy due to volume contraction, or mild form of hypertrophic cardiomyopathy. No obstructive disease noted.

Image Interpretation

The left ventricle presented excessive free wall and septal thicknesses with hypertrophic contour. The left ventricular chamber was somewhat restricted. Septal deviation was noted, and impinged on the left ventricular outflow tract (LVOT). Significant myocardial remodeling and fibrosis was noted. Contractility of the ventricular walls was considered excessive for this patient as evidenced by the fractional shortening measurement. The left ventricular outflow tract demonstrated turbulent laminar flow without evidence of hemodynamically significant insufficiency. Excessive LVOT velocity was present.

Outcome

The Norvasc and prednisone were continued and LRS fluids at home were added.

Clinical Differential Diagnosis

Hypertension – primary or idiopathic, secondary (hyperthyroidism, chronic renal failure, HCM). Elevated AST – degenerative hepatopathy, cholangiohepatitis complex, neoplasia, drug-induced. Hypercalcemia – renal disease, neoplasia, granulomatous disease. Azotemia – chronic renal disease (previously diagnosed).