Which condition is least likely to have a 'ground glass' appearance on echocardiography?

A 'ground glass' appearance on echocardiography is typically associated with conditions that affect the myocardium through infiltration or fibrosis, leading to alterations in echogenicity. This term describes a subtle echogenicity that resembles ground glass and is often seen in pathologies like infiltrative myocarditis, amyloid cardiomyopathy, and restrictive cardiomyopathy, where the heart tissue becomes less compliant due to abnormal deposits or growths.

Hypertrophic cardiomyopathy, on the other hand, primarily involves a thickening of the heart muscle due to genetic factors and does not typically result in the diffuse, infiltrative appearance that is characteristic of a 'ground glass' echo pattern. Instead, hypertrophic cardiomyopathy is associated with localized thickening of the myocardium and does not present the same diffuse echogenic changes seen in the other conditions listed.

Therefore, the condition that is least likely to exhibit a 'ground glass' appearance is hypertrophic cardiomyopathy. Understanding the unique characteristics of these cardiomyopathies helps clarify why hypertrophic changes do not reflect a ground glass echogenicity while infiltrative and restrictive processes do.