高血圧の経過中に肥大型閉塞性心筋症の像を呈した1例

A case of hypertrophic obstructive cardiomyopathy observed during mild hypertension

　高血圧に伴う左室肥大は，高血圧の進展とともに求心性肥大を生じ，ついで拡張性肥大となる。比較的軽症の本態性高血圧症のなかに，心電図上著明な左室肥大および心エコー図上僧帽弁前尖収縮期前方運動（Systolic Ant—erior Movement, SAMと略す）を示す症例が報告され^1,2），特発性心筋症との関連性が注目をあつめている。また，高血圧の経過中に非対称性中隔肥大（Asymmet—ric Septal Hypertrophy,ASHと略す）を生じることはすでに指摘されているが^1），肥大型閉塞性心筋症（Hyper—trophic Obstructive Cardiomyopathy,HOCMと略す）の像を呈する症例の報告は少ない^3）。とりわけ，本邦においてはかかる症例の報告はみられない。

　そこで，われわれは高血圧の経過中にHOCMの像を呈した症例を経験したので，高血圧と特発性心筋症との関連性，さらに臨床的特微について述べる。

A case of hypertrophic obstructive cardiomyo-pathy observed during mild hypertension was reported. There was no family history of idiopathic cardiomyopathy. A 56-year-old man was found to have mild hypertension without symptoms at the age of 41. Electrocardiogram at the age of 44 revealed marked left ventricular hypertrophy (LVH) inconsistent with levels of blood pressure. Blood pressure was extremely labile. He noticed chest oppression and palpitation during periods of extreme lability of blood pressure and during treat-ment for hypertension. Electrocardiogram on the admission revealed marked LVH and echocardio-gram showed systolic anterior movement of the mitral valve. Cardiac catheterization demonstrated elevation of the left ventricular endodiastolic pres-sure and presence of the pressure gradient between outflow tract and apex of the left ventricle.

Hypertrophic obstructive cardiomyopathy in our case seemed to be a secondary change induced by mild systemic hypertension on the basis of some predisposition.