心房頻拍に対するFlecainideの有用性に関する検討

Effect of Flecainide for Atrial Tachycardia in Children

　症候性の心房頻拍6例（男2例，女4例），3カ月〜19歳（平均年齢13歳）を対象とし，flecainideの経口投与を行った．投与前および投与後2週間以後にHolter心電図を用い，有効性を検討した．頻拍の機序は自動能亢進5例，心房内回帰頻拍1例であった．自動能亢進による心房頻拍5例中，頻拍が完全に停止した症例が2例，頻拍の頻度および頻拍レートが遅くなった例が2例であった（有効率80％）．これら4例のflecainide投与前後の平均心拍数は毎分106±42から毎分93±31へと低下し，1日の最高心拍数も毎分205±47から毎分145±44へと低下したが，症例数が少なく統計学的には有意差は認められなかった．投与前の頻拍の出現様式，心房頻拍のレート，平均心拍数，心房頻拍の割合には停止症例，非停止症例間で一定の傾向は認められなかった．心房内回帰性頻拍ではflecainideは無効であった．投与を中止するような副作用は認められなかった．自動能を機序とする心房頻拍にflecainideは有効と思われた．

Flecainide was administered to 6 patients with symp-tomatic atrial tachycardia (2 males and 4 females, age 3 months to 19 years, mean age 13 years). The efficacy of flecainide was evaluated by ambulatory electrocardi-ogram. The mechanisms of tachycardia were automaticity in 5 patients and reentry in 1 patient. In 5 patients with automatic atrial tachycardia, tachycardia was completely suppressed in 2 patients and tachycar-dia rate was decreased in 2 patients. Symptoms continued in 2 patients. Total efficacy rate was 80% when cases with partial snppression were included. Efficacy was not apparently influenced by tachycardia emergency mode, rate of tachycardia, mean heart rate and the percentage of atrial tachycardia. Flecainide was ineffective in a case of reentrant atrial tachycardia. There was no adverse effect in these patients. Flecainide is an effective medicine for automatic atrial tachycardia.