The emerging role of cardiovascular magnetic resonance in refining the diagnosis of hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy (HCM) is a genetically and phenotypically diverse disease with some patients at risk of sudden death or heart failure. Maron et al. used cardiovascular magnetic resonance, in a specialist clinic setting, to identify a cohort of HCM patients with left ventricular apical aneurysms that were not detected by conventional echocardiography. Apical aneurysms were variable in morphology and associated with scarring, thrombus, and the occurrence of monomorphic ventricular tachycardia. Preliminary follow-up data indicate that they could be associated with poor medium-term outcome. The paper by Maron et al. continues the gradual evolution of our understanding of HCM, highlighting an important clinical subset of patients and a phenotypic feature of HCM. The study also identifies cardiovascular magnetic resonance as an important technique for phenotyping cardiac diseases, identifying prognostically important features, and highlighting pathophysiological mechanisms.