中村 隆志¹, 松原 欣也¹, 古川 啓三¹, 北村 浩一¹, 東 秋弘¹, 杉原 洋樹¹, 勝目 紘¹, 中川 雅夫¹, 宮尾 賢爾²

Takashi NAKAMURA¹, Kin-ya MATSUBARA¹, Keizo FURUKAWA¹, Hirokazu KITAMURA¹, Akihiro AZUMA¹, Hiroki SUGIHARA¹, Hiroshi KATSUME¹, Masao NAKAGAWA¹, Kenji MIYAO²

¹京都府立医科大学第二内科, ²京都第二赤十字病院循環器内科

¹Second Department of Medicine, Kyoto Prefectural University of Medicine, ²Department of Medicine, Kyoto Second Red Cross Hospital

キーワード : Doppler echocardiography, Hypertrophic cardiomyopathy, Midventricular obstruction, Left ventriculography

Using Doppler echocardiography, intraventricular flow conditions were assessed in 10 cases of hypertrophic cardiomyopathy with midventricular obstruction (MVO). This data was compared with left ventricular wall dynamics obtained using left ventriculography.
Real-time color flow imagings from the apical window revealed that all patients had systolic turbulent flow originating in the obliterated midcavity of the left ventricle. The peak flow velocity at rest ranged from 2.5 to 3.8 m/sec (mean 3.0). In diastole, two types of flow profiles were observed at the midventricle. Five patients with hyperkinetic apical segments had fast flow toward the apex during the rapid filling phase. The peak flow velocity was significantly incrased as compared with peak velocity of transmitral rapid filling flow (112±30 vs 45±9 cm/sec; pIn conclusion, MVO creates pressure gradients between the apex and the base not only in systole but also in early diastole. Obliteration of the midcavity may deteriorate apical wall function, which can be the cause of a curious gradient with higher apical pressure seen in early diastole. Doppler echocardiography is useful in evaluating these abnormal left ventricular dynamics with reference to the intracavitary flow conditions seen in MVO.