高度ヒス束内ブロックによるEscape-Capture Bigeminy

Escape-Capture Bigeminy due to 3:1 Intra-hisian block

　Escape-Capture Bigeminy^1）とは補充収縮と心室捕捉とが一拍毎交互に出現する特異な形の不整脈である。その出現機序には幾通りかの可能性があり^2,3），Scham—rothの総説^4）では高度房室ブロックによる場合はまれであると述べられている。私共は高度房室ブロックによるEscape-Capture Bigeminyを経験し，ヒス束心電図にてヒス束内ブロック^5,6）の所見が得られたので報告する。

Escape-Capture Bigeminy due to 3: 1 intra-hisian block was observed in a case of 73 year-old wom-an.

She admitted with exertional dyspnea of recent onset. She was edematous and her pulse was bradycardic (30 per minute). Chest X-ray film revealed marked cardiomegaly and pulmonary con-gestion. Her electrocardiogram showed escape-capture bigeminy due to 3:1 atrioventricular block with normal QRS-T complexes (QRS width 0.08 sec.). His bundle electrocardiogram showed H-H' block. Captured beats consisted of A, H, H' and V waves, while escaped beats of H' and V waves. The intervals of PA, AH, HH' and H'V were 30, 80, 50, and 35 msec., respectively.