Morphologic variants of hypertrophic cardiomyopathy

HCM typically presents with asymmetric or localized areas of LV hypertrophy, which are diagrammed in B to J.

(A) Normal LV wall thickness.

(B) ASH.

(C) Sigmoid septum, which is more common in older adults.

(D) Midcavity hypertrophy associated with midcavity obstruction.

(E) Predominantly free wall hypertrophy, an unusual pattern in HCM.

(F) LV wall thinning (associated with low LV ejection fraction) and biatrial enlargement.

(G) Predominantly apical LV hypertrophy.

(H) Severe concentric hypertrophy with cavity obliteration.

(I) Biventricular hypertrophy.