Morphological onset and early diagnosis in apical hypertrophic cardiomyopathy: A long term analysis with nuclear magnetic resonance imaging

Objectives. A long-term follow-up study with nuclear magnetic resonance (NM R) imaging was undertaken to detect the morphological onset and to establis h the early diagnosis in apical hypertrophic cardiomyopathy (HCM). Background. A spadelike configuration on left ventriculogram (LVG) is regar ded as a diagnostic criterion for the classical apical HCM. There also exis ts a segmented hypertrophy at the apical level without indicating the spade like features (a nonspade configuration). To detect the hypertrophied myoca rdium of the nonspade configuration, circumferential scrutiny of the apex i s required. Although both configurations can be underlying causes of giant negative T waves, etiological relationship between the two is not clarified . Methods. The criteria for the spadelike configuration defined on left ventr icular short-axis NMR images were as follows: (apical maximal thickness gre ater than or equal to 15 mm), (apical anterior thickness over basal anterio r thickness greater than or equal to 1.3) and (apical posterior thickness o ver basal posterior thickness greater than or equal to 1.3). Thirteen patie nts who had predominant hypertrophy (greater than or equal to 15 mm) at the apical level without the spadelike configuration underwent NMR imaging twi ce before and after 54 +/- 10 months' follow-up. Results. Apical hypertrophy that had been confined to the lateral wall in f our, the anterior-lateral wall in two, and the septal-anterior wall in one developed to become circumferential hypertrophy that fulfilled the criteria for the spadelike configuration after the follow-up period. Conclusions. The spadelike configuration can begin with the nonspade config uration and therefore, both can constitute a single disease entity of apica l ACM. The early diagnosis of apical HCM can be achieved by identifying the hypertrophy frequently confined to the lateral wall at the apical level. ( C) 1998 by the American College of Cardiology.