Dilated Cardiomyopathy (DCM) in a 7 year old (62kg) Great Dane.

By Dr Phoebe Nunn, May 2025, Soundiagnosis

History: 

A 7- year old Great Dane presented to the clinic with coughing and wheezing. On physical exam a severe irregular irregular arrhythmia was auscultated. An echocardiogram was recommended to assess for structural cardiac disease.   

Soundiagnosis Echocardiogram Findings:  

The echocardiogram showed a severely dilated left ventricle consistent with eccentric hypertrophy, moderate left atrial dilation, moderate mitral regurgitation and subjective dilation of the right atrium and ventricle. The dilation of the left ventricle in conjunction with a significantly reduced fractional shortening and increased E-point septal separation measurement (EPSS)  was consistent with reduced systolic function.  

The severe arrhythmia meant that certain Doppler measurements (e.g. velocity of the mitral regurgitation) were not able to be accurately recorded. 

Diagnosis:  

Dilated Cardiomyopathy (DCM) Phenotype (characterised by left ventricular dilation and systolic dysfunction).  

Comments and Outcome: 

The diagnosis of DCM phenotype can be difficult as there is no one definitive characteristic of the disease, rather patients must fulfill a number of criteria (e.g. Left ventricular dilation, reduced fractional shortening etc). As we know, not all cases are textbook and some patients may have multiple abnormalities on echocardiogram, but not meet the criteria to be classified as a DCM phenotype. However, this case was a good example of a patient who did meet the criteria.  

Primary (idiopathic) DCM is also challenging as it is a diagnosis of exclusion. There are many secondary causes of DCM such as grain-free/legume based diets, taurine deficiency, drugs, myocarditis, arrythmia-induced cardiomyopathy , as well as end stage of other certain heart conditions (e.g. mitral valve dyplasia, degenerative valve disease etc). These should be excluded wherever possible.  

This patient was started on pimobendan. Thoracic radiographs were recommended to assess for the presence of pulmonary oedema and commence diuretics as indicated. An electrocardiogram (ECG) was also performed to see if the arrhythmia could be treated.  

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