In conventional diagnostic criteria published by American heart association (AHA)/American college of cardiology foundation (ACCF) in 2011, or European society of cardiology (ESC) in 2014, the LV wall thickness≥15 mm is the unified diagnostic criteria of HCM. These guidelines, however, did not give additional regulations or instructions for the diagnosis of AHCM. It is suspected that these criteria may be too strict for AHCM, as the normal left ventricular wall thins towards the apex and the normal values are lower naturally in the apical versus the basal segments.