Suzuki J, Watanabe F, Takenaka K, Amano K, Amano W, Igarashi T, Aoki T, Serizawa T, Sakamoto T, Sugimoto T
Second Department of Internal Medicine, Faculty of Medicine, University of Tokyo, Japan.
J Am Coll Cardiol. 1993 Oct;22(4):1175-81. doi: 10.1016/0735-1097(93)90434-3.
The aim of this study was to elucidate the clinical importance of a new subtype of apical hypertrophic cardiomyopathy that could not be diagnosed with the classical diagnostic criteria.
Apical hypertrophic cardiomyopathy is recognized by a characteristic spade-shaped intraventricular cavity on the end-diastolic left ventriculogram in the right anterior oblique projection, often associated with giant negative T waves [negativity > or = 1.0 mV (10 mm)]. As an underlying cause of giant negative T waves, an additional new subtype of apical hypertrophic cardiomyopathy has been identified.
In 40 patients with inverted T waves (negativity > or = 0.5 mV), including 26 patients with giant negative T waves, nuclear magnetic resonance (NMR) long-axis images corresponding to the left ventriculogram in the right anterior oblique projection and short-axis images at various levels, including the apical level, were obtained to define the site of hypertrophied myocardium.
Long-axis images indicated a spadelike configuration in 17 patients, whereas this diagnostic configuration was not present in the other 23 patients. Nine of these 23 patients had significantly hypertrophied myocardium at the basal level. In the 14 remaining patients, short-axis images indicated no hypertrophy at the basal level and proved that the area of hypertrophied myocardium was confined to a narrow region of the septum or the anterior or lateral wall at the apical level (nonspade apical hypertrophic cardiomyopathy). The hypertrophied myocardium of the nonspade type was so narrowly confined that the mass did not form a spadelike configuration or could not be detected on the long-axis image.
Nonspade apical hypertrophic cardiomyopathy was newly identified on NMR short-axis images, and this could be an additional, important underlying cause of moderately to severely inverted T waves.
本研究旨在阐明一种无法用经典诊断标准诊断的新型心尖肥厚型心肌病的临床重要性。
心尖肥厚型心肌病在右前斜位舒张末期左心室造影上表现为特征性的铲形心室内腔，常伴有巨大倒置T波[倒置幅度≥1.0 mV（10 mm）]。作为巨大倒置T波的一个潜在原因，已发现一种新的心尖肥厚型心肌病亚型。
对40例T波倒置（倒置幅度≥0.5 mV）的患者，包括26例巨大倒置T波患者，获取与右前斜位左心室造影相对应的核磁共振（NMR）长轴图像以及包括心尖水平在内的不同层面的短轴图像，以确定肥厚心肌的部位。
长轴图像显示17例患者呈铲形结构，而其他23例患者未出现这种诊断性结构。这23例患者中有9例在基底部有明显肥厚的心肌。在其余14例患者中，短轴图像显示基底部无肥厚，并证实肥厚心肌区域局限于心尖水平的室间隔或前壁或侧壁的狭窄区域（非铲形心尖肥厚型心肌病）。非铲形类型的肥厚心肌局限非常狭窄，以至于其质量未形成铲形结构或在长轴图像上无法检测到。
非铲形心尖肥厚型心肌病是通过NMR短轴图像新发现的，这可能是中度至重度T波倒置的另一个重要潜在原因。
