Letters Section Editor: Robert M. Golub, MD, Senior Editor.
In Reply: Dr Refaat inquires about the small morphologic subset (approximately 3% of patients with HCM) in whom mild hypertrophy is confined to the most distal portion of the left ventricular chamber. Of our 506 study patients, we are aware of only 2 high-risk participants who could be considered to have the apical form of HCM (neither of whom received an appropriate shock). This probably reflects the low-risk status of many patients within this morphologic subgroup.1- 4 Of note, those patients with HCM in the study cohort who did experience appropriate shocks for life-threatening ventricular tachycardia or fibrillation had substantial left ventricular hypertrophy (mean wall thickness, 23 [SD, 6] mm, compared with the thicknesses of 16-20 mm that are usual for localized apical hypertrophy3,5).
Maron BJ, Spirito P. Prognosis of Apical Hypertrophic Cardiomyopathy—Reply. JAMA. 2007;298(17):2006. doi:10.1001/jama.298.17.2006-b