Diversity of the Localization of Myocardial Hypertrophy at the Apical Level in Patients with Apical Hypertrophy Evaluated by Magnetic Resonance Imaging

Abstract

To evaluate the distributions of hypertrophy at the apical level in 20 patients with apical hypertrophy, end-diastolic wall thicknesses were measured on the left ventricular short axis image using magnetic resonance imaging. Distributions of hypertrophy with wall thickness equal to or more than 1.5 cm at the apical level were circumferential in 2 patients, septal-anterior-lateral in 7, septal-anterior in 2, anterior-lateral in 2, septal in 1, anterior in 3 and lateral in 3. Apical hypertrophy could not be diagnosed in 6 of 20 patients on left ventriculograms in right anterior oblique view nor on magnetic resonance long axis images corresponding to left ventriculogram, because the septal and lateral walls could not be evaluated on this view. Localized apical hypertrophy whose hypertrophied muscles are confined to the apical septum or the apical anterior wall or the apical lateral wall has been discovered. Although ‘spade like’ configuration on left ventriculography is considered as the diagnostic criterion, circumferential evaluations of the apex using short axis image are mandatory for the diagnosis.

Relationship Between Electrocardiographic Features and Distribution of Hypertrophy in Patients With Hypertrophic Cardiomyopathy

“…Recent advances in MRI technology have enabled true short-axis images of the left ventricle to be obtained and have provided clear margins of both the endocardium and the epicardium at various levels. 4 …”

“…Advances of electrocardiogram-gated MRI have enabled the accurate measurement of the wall thickness of the entire left ventricle. 3,4 In the present study, we used MRI to evaluate the relationship between electrocardiographic features and the distribution of hypertrophy in patients with HCM.…”

Evaluation of the Heart with Magnetic Resonance Imaging.

“…The hidden myocardial hypertrophy in these patients was so narrowly confined to the lateral wall at the apical level that left ventriculogarphy could not detect the hypertrophy because left ventriculography in this projection could not evaluate the lateral wall but could evaluate the anterior and posterior walls. [20][21][22] Left ventriculography with biplane methods still cannot evaluate the apex circumferentially. By circumferentially scrutinizing the left ventricular apex on the short-axis images with cardiac MR imaging, a subtype of apical hypertrophic cardiomyopathy whose hypertrophied myocardium was often localized at the lateral wall at the apical level was identified as an underlying disorder for giant negative T waves.…”

“…By circumferentially scrutinizing the left ventricular apex on the short-axis images with cardiac MR imaging, a subtype of apical hypertrophic cardiomyopathy whose hypertrophied myocardium was often localized at the lateral wall at the apical level was identified as an underlying disorder for giant negative T waves. [20][21][22] Moreover, a long-term analysis with MR imaging revealed that the confined hypertrophy developed to become circumferential hypertrohy at the apex, i.e., classical spadelike apical hypertrophic cardiomyo-pathy. 23) This fact indicates that the nonspade hypertrophic cardiomyopathy is the morphological beginning or onset of the apical hypertrophic cardiomyopathy and the nonspade and the classical spade hypertrophic cardiomyopathies constitute a common single disease entity.…”