Differentiation of solitary papillary muscle hypertrophy from apical hypertrophic cardiomyopathy.

Hypertrophy From Apical Hypertrophic Cardiomyopathy To the Editor: We read with interest the article by Reddy et al1 regarding a case with apical hypertrophic cardiomyopathy. The authors said that the 2D echocardiograph obtained from this patient indicated hypertrophy of the apex and that 201-Tl scintigraphic imaging demonstrated an increased count in the apical segment. However, because there was a clear groove or space between the hypertrophic segment and the lateral free wall in the 2D echocardiograph, we think that the hypertrophic segment in this patient was not the left ventricular free wall, but rather the anterolateral papillary muscle, and that the scintigraphic finding was also related to the hypertrophic papillary muscle. Recently, we reported that patients with solitary papillary muscle hypertrophy showed left ventricular hypertrophy with not-so-prominent but symmetrical, negative T-waves on the ECG. Some of these patients had relatives with clinical features of hypertrophic cardiomyopathy.2 At the present time, we consider isolated papillary muscle hypertrophy a newly identified subtype of an early form of hypertrophic cardiomyopathy. We thought that the case reported by Reddy et al1 had features typical of and suggestive of solitary papillary muscle hypertrophy; thus, we think it is not a case with apical hypertrophic cardiomyopathy with hypertrophy in the apical segment of the left ventricular free wall and/or ventricular septum.