原 賢治¹, 小柳 孝司¹, 進 岳史¹, 坂元 力¹, 久保田 史郎², 中野 仁雄¹

Kenji HARA¹, Takashi KOYANAGI¹, Takeshi SHIN¹, Chikara SAKAMOTO¹, Shiro KUBOTA², Hitoo NAKANO¹

¹九州大学医学部婦人科産科学教室, ²久保田産婦人科

¹Department of Gynecology and obstetrics Kyushu University, Faculty of Medicine, ²Kubota Obstetrics and Gynecology

キーワード : congenital complete atrioventricular block, prenatal diagnosis, echocardiogram, atrioventricular valve

Using real-time ultrasound equipment (Toshiba SSH-11A and Toshiba SSL-53M), the investigation was done on the 4 fetuses in utero with complete atrioventricular block. Based on the echocardiographic findings, antenatal diagnosis was made:
1) The atrioventricular valves offer two different types of wave components, one of which is characterized by the high amplitude and long duration on the M-mode record, the other having the only small deflection as termed "A" kicking.
2) These two components possess the different cycles with each other. Large wave components were thought to correspond to the ventricular dilatation. Considering the direction of blood flow at the level of atrioventricular canal, the small components were thought to represent the atrial contraction. These cases were confirmed as having the complete atrioventricular block by the electrocardiographic findings in the early neonatal period. 　
Accordingly, the antenatal diagnosis of complete atrioventricular block could be made by the detection of the large and small waves with independent and different cycles.