Sonopath’s October Case of the Month — SAM-I-AM (Systolic Anterior Motion)

October 4, 2016
Animal Sounds

Ever want to know how to dissect out a HCM heart sonographically regarding hypertrophy, dynamic outflow obstruction (SAM), bi-directional turbulence and decide if it’s clinical or not?

Our SonoPath Cardiologist, Maggie Machen DACVIM, demonstrates Educational Telemedicine™ artistry in her evaluation of the cat heart; imaged by Andi Parkinson, RDMS of Intrapet Imaging, Baltimore, MD, in October, 2016 SonoPath case of the month.

Patient Information:

Age:         10 Years
Gender:    Female, Spayed
Species:   Feline
Breed:      Domestic Short-Haired

Symptoms:

  • Presented to Assess Murmur and Anesthetic Risk Prior to Dental Prophylaxis
  • An Exam 1-Month Prior Revealed a Grade III/VI Murmur

Exam Findings:

  • CBC/Chem/UA were all WNL

Imaging/Sampling:

  • Echocardiogram
  • Radiographs

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
  • Mild left atrial enlargement present
  • No right atrial enlargement present

  • Elevated RVOT velocity consistent with a dynamic obstruction
  • Mild to moderate systolic anterior motion (SAM) of the mitral valve present, with a mildly elevated LVOT velocity
  • Moderate eccentric mitral regurgitation present secondary to SAM
  • No other obvious valvular regurgitation is present
  • No pericardial effusion noted
  • No pleural effusion appreciated

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.
Concentric left ventricular hypertrophy in 5 chamber right parasternal long axis with bidirectional turbulence through the LVOT and mitral regurgitation typical for feline HCM. Sectorial LV hypertrophy demonstrated in right parasternal short axis. LVOT turbulence in right parasternal 5 chamber long axis.