Apical hypertrophic cardiomyopathy or left ventricular non-compaction? A difficult differential diagnosis

Abstract

Hypertrophic cardiomyopathy (HCM) is a familial cardiac disease caused by mutations in one or more of 12 genes encoding protein components of the cardiac sarcomere.1,2 The disease is transmitted with an autosomal dominant trait and a variable penetrance. The phenotypic features of HCM may develop at any age from infancy to adulthood, and are characterized by a great heterogeneity in the extent, magnitude, and distribution of left ventricular (LV) hypertrophy.1 Apical HCM is a relatively rare morphological expression of the disease (<5% of patients), in which LV wall thickening is confined to the most distal portion of the ventricle, below the papillary muscle level.3,4 This form of HCM is more frequently sporadic, but may also be encountered in the context of clinical screening of HCM families with more common patterns of distribution of LV hypertrophy.3,4 A few families have also been reported with autosomal dominant inheritance of an apical form of HCM.5 The clinical course of apical HCM appears to be generally benign, without severe symptoms or major cardiac events. Indeed, a particularly low annual cardiovascular mortality rate (0.1%) was reported during a mean follow-up of 9 years in a survey of the largest available cohort of patients with apical HCM (a total of 105 patients).3 Non-compaction of LV myocardium is an increasingly recognized but apparently uncommon cardiomyopathy, characterized by a hypertrophied left ventricle with multiple trabeculations and deep intertrabecular recesses communicating with … *Corresponding author. Tel: +39-010-5634170; fax: +39-010-5634180. E-mail address : paolo.spirito{at}galliera.it