肥大型心筋症合併WPW症候群にカテーテルアブレーションを施行した1例

A Case of Wolff-Parkinson-White Syndrome with Hypertrophic Cardiomyopathy Treated by Radiofrequency Catheter Ablation

　症例は37歳，男性．1991年，肥大型心筋症（HCM），WPW症候群と診断され経過観察されていたが，房室回帰性頻拍の薬剤コントロールが困難になったためカテーテルアブレーション目的に当科に入院した．心電図では左側自由壁のKent束が示唆された．はじめ通常の経大動脈アプローチにてアブレーションを施行したが，カテーテルの操作性が悪く不成功に終わり，経左房アプローチに変更したところで成功した．アブレーションの翌日，頻拍に無関与な右側後中隔起源のデルタ波が新たに出現した．本例では大動脈アプローチでは不成功に終わり，原因として内腔が狭くカテーテル操作がしづらかったこと，心内膜からKent束への距離が遠い可能性，Kent束がmulticomponentである可能性などが考えられた．また，最終的には複数副伝導路であることが明らかになった．以上より，HCM合併WPW症候群のカテーテルアブレーションに際してはアプローチ法を含めた術前の十分な検討が重要と考えられた．

A case of WPW syndrome with hypertrophic car-diomvopathv (HCM) is reported. The patient was a 37 -year-old male, who experienced recurrent and drug resistant episodes of palpitations. Electrocardiogram showed negative delta wave in aV_L and a normal QRSaxis, suggesting a left lateral accessory pathway. The electrophysiological study revealed that the mechanism of palpitations was atrioventricular reentrant tachycar-dia (AVRT) using Kent bundle existing in the left-lateral wall, so radiofrequency catheter ablation (RFCA) was performed. An initial RFCA performed via the retrograde aortic approach was unsuccessful because of the difficulty in catheter manipulation. The second RFCA using the femoral vein approach via foramen ovale was performed successfully and there was neither antegrade nor retrograde conduction ofaccessory pathway. Though new delta wave originated from posteroseptal wall was documented on the next day after successful catheter ablation, there was no recurrence of AVRT during a follow up period of 10 months.

From the experience described above, it is suggested that close planning is needed to perform a catheter ablation for patients with HCM.