Blueberry-on-Top Phenomenon in Apical Variant Hypertrophic Cardiomyopathy
Apical hypertrophic cardiomyopathy (AHCM) is a rare phenotypic variant of hypertrophic cardiomyopathy (HCM), most commonly seen in Asian men (Yamaguchi syndrome). Apical HCM is characterized by hypertrophy predominantly affecting the cardiac apex, with an “ace of spades”–shaped left ventricular (LV) cavity best seen on the 4-chamber view of a transthoracic echocardiogram (TTE). However, TTE can be falsely negative in 30% of AHCM cases, largely due to difficulties in delineating endocardial border.