LV outflow tract obstruction is independently associated with adverse HCM-related outcomes,26 may benefit from surgical intervention, and is amenable to treatment with myosin inhibitors.27 It is associated with septal hypertrophy and ventricular remodeling,28 although it may also occur in milder cases of HCM.29 We found that the phenotype in branch (2) with pronounced mid-to-basal asymmetrical hypertrophy in a diffusely hypertrophic LV was strongly enriched for stress-confirmed LV outflow tract obstruction and hyperdynamic function. Here, MYH14 is linked to cardiac hypertrophy.