Case Of the Month

HCM Heart In A 10-Year-Old FS DSH Cat: Our Case of the Month October 2016

A 10-year-old, FS, DSH cat was presented for assessment of murmur and anesthetic risk prior to dental prophylaxis. An exam 1-month prior revealed a grade III/VI murmur. NT-proBNP was >1500pmol/L. The patient was on no medications at the time of ultrasound. CBC/Chem/UA were all WNL. Radiographs showed cardiomegaly.

DX

Hypertrophic obstructive cardiomyopathy.

Outcome

This indicates LV hypertrophy with a dynamic LVOT obstruction (SAM). There is mild left atrial dilation, indicating the risk of a future spontaneous CHF and/or a thrombotic event may be elevated. There is also a benign RV outflow obstruction (DRVOTO). If able, administer titrating dose of atenolol: 2.5mg tablets; Give tab once daily. Recheck heart rate in 1-2 weeks with target stressed rate of 140-160bpm 12-24 hours post administration. Increase as needed until target reached. Screening blood pressure is recommended. Recommend recheck echocardiogram in 6 months to assess for progression, sooner if clinical issues arise.

Image Interpretation

The left ventricular wall is moderate to severely asymmetrically hypertrophied. There is a diffusely hyperechoic endocardium consistent with fibrosis and ventricular remodeling. Asymmetric papillary muscle hypertrophy and atrophy. The right ventricle is subjectively normal in size and morphology. There is mild left atrial enlargement present. No right atrial enlargement present. Elevated RVOT velocity consistent with a dynamic obstruction. There is mild to moderate systolic anterior motion (SAM) of the mitral valve present, with a mildly elevated LVOT velocity. There is moderate eccentric mitral regurgitation present secondary to SAM. No other obvious valvular regurgitation is present. There is no pericardial effusion noted. No pleural effusion appreciated.