Enlarged left atrium, atrial fibrillation and adverse outcome in hypertrophic cardiomyopathy: is there a difference between apical and non-apical phenotype?

Apical hypertrophic cardiomyopathy (HCM) was first described in 1976 by Sakamoto and colleagues as a novel cardiac condition characterised by a spade-shaped left ventricular cavity, apical hypertrophy and giant negative T waves.1 Contemporary reports of apical HCM describe it as a phenotypic variant of HCM in which hypertrophy is localised to the left ventricular apex with or without midsegment involvement. Apical HCM is observed worldwide, although it is traditionally reported more frequently in Asian countries (20%–40% of all HCMs) compared with Western countries (3%–11% of all HCMs). In general, patients with apical HCM exhibit mild symptoms and follow a more benign course with a lower mortality rate compared with other forms of HCM. However, numerous case reports and studies suggest considerable overlap between apical hypertrophy, midventricular obstruction and apical aneurysm. Further, our prior study and a report by Maron and colleagues demonstrated a largely unfavourable clinical course for...