Hypertrophic Cardiomyopathy With Apical Aneurysm
Two patients are presented with an uncommon phenotypic expression of hypertrophic cardiomyopathy (HCM), characterized by a left ventricular apical aneurysm associated with midventricular hypertrophy. Both patients were identified at relatively advanced age (60 and 78 years) and had modest symptoms and functional disability corresponding to New York Heart Association functional class II. Neither of the patients had a left ventricular outflow gradient at rest on echocardiography. Cardiac cine and gadolinium-enhanced T1-weighted MRI (CMR) performed at 1.5 T provided striking images of the greatly distorted left ventricular morphology. Both patients showed markedly abnormal gadolinium uptake in the aneurysm consistent with extensive fibrosis (see Figure). The apical aneurysm was the likely source of repetitive bursts of monomorphic ventricular tachycardia in both patients on ambulatory Holter monitoring, which triggered the recommendation for prophylactic implantation of a cardioverter-defibrillator. CMR proved superior to two-dimensional echocardiography for visualization of the apical aneurysms, which is of particular importance should surgical intervention be contemplated in the future. The mechanism by which the apical wall thinning and aneurysm develop in this subgroup of HCM patients is currently unresolved.