Hypertrophic cardiomyopathy and cardiac muscle cell disorganization revisited: relation between the two and significance.

The disorganized arrangement of cardiac muscle cells in left ventricular (LV) myocardium of patients with hypertrophic cardiomyopathy (HCM) was first described by Teare in his initial report on this condition in 1958.l Teare described eight patients with “asymmetric hypertrophy or muscular hamartoma of the heart” and a “bizarre and disorganized arrangement of muscle bundles” in the asymmetrically hypertrophied ventricular septum (IVS). During the ensuing several years a number of reports based on analysis of tissue obtained at necropsy, operation, or biopsy confirmed the observations of Teare and concluded that a disorganized arrangement of cardiac muscle cells in the IVS was a characteristic and consistent morphologic feature of patients with HCM.“-‘* Electron microscopic analysis showed that the disorganized cells often had highly irregular shapes and large branches that extended in several directions and formed intercellular junctions with several adjacent cel1s.j Subsequently, however, bizarre cellular architecture was identified in the LV wall of patients with congenital or acquired cardiac diseases other than HCM.‘“-30 This finding led some investigators to dispute the usefulness of IVS disorganization as a marker of HCM.‘“, ?4-26 The present report reexamines the issue of cardiac muscle cell disorganization in the LV wall of patients with HCM and discusses the potential significance of this morphologic alteration.