左室容量負荷疾患における心電図陰性U波の検討—大動脈弁閉鎖不全と僧帽弁閉鎖不全との対比

Negative U-wave in patients with left ventricular volume overload: aortic versus mitral regurgitation

　心電図上の陰性U波は高血圧疾患，虚血性心疾患および弁膜疾患などで出現しやすいことが知られている^1〜5）。しかし，各疾患における陰性U波出現の機序および成因についてはまだ十分解明されていない。

　陰性U波の成因の1つに，左室容量の増大による心筋の伸展など，機械的要素が関与しているとの報告がなされている^6,7）。

Twenty-one patients with aortic or mitral regurgitation were subjected to this study in order to discuss the relationships of frequency of negative U-wave on electrocardiogram and degree of left ventricular volume overload on echocardiogram.

The following results were obtained.

1. The frequency of negative U-wave was significantly greater in aortic regurgitation (87.9%) than in mitral regurgitation (4.8%).

2. Comparing with mitral regurgitation, aortic regurgitation gave a larger electrocardiographic voltage in SV₁ and echocardiographic diameter in aortic root, and a smaller echocardiographic diameter in left atrium.

3. The duration, depth and electrocardiographic lead in negative U-wave did not show any signif-icant correlations with echocardiographic or other electrocardiographic measurements.

4. Although not much information was available in terms of discussing the background, high inci-dence of negative U-wave in patients with aortic regurgitation proved to he clinically useful electro-cardiographic findings.