右室負荷疾患における陰性U波の有用性について

Usefulness of electrocardiographic negative U-wave in patients with chronic right ventricular overload

　心電図における陰性U波は，冠動脈疾患，高血圧，大動脈弁閉鎖不全，心筋症など左室負荷疾患を有する例によく認められるが^1〜10），右室負荷疾患例に関する報告は少ない^11〜13）。

　今回，我々は右室負荷疾患例において認められた陰性U波と種々の右室負荷所見との関連について検討した。

In order to compare the relation of negative U-wave (NU) to chronic right ventricular overload (RVO), 35 patients with various types of RVO were studied and divided into 4 groups ; 11 of atrial septal defect (ASD), 13 of ASD with pulmonary hypertens-ion (PH), 6 of primary PH, and 5 of pulmonic steno-sis (PS). NU was present in 77% of ASD with PH, 100% of primary PH, and 80% of PS, and none of ASD without PH. Cases with NU demonstrated significantly higher prevalence (p< 0. 001) of high RV pressure, thick RV wall on echocardiogram and significant RV hypertrophy pattern on electrocar diogram in comparison of cases without NU. NU was present in 16 of 19 patients with RV pressure higher than 60 mmHg, in 20 of 21 with RV thickness greater than 5 mm, and 16 of 18 with RV₁+ SV₅ larger than 2 mV. These results suggested that NU in RVO might well be related to thickened RV wall in association with chronic RV pressure overload. It was concluded, therefore, that the presence of NU in patients with RVO proved to be an extremely useful parameter in assessing the degree of RV pressure overload.