Shoichi Ono

Different recovery process of ST depression on postexercise electrocardiograms in women in standing and supine positions.

False-positive exercise test responses are frequently observed in women. To differentiate a false-positive from a true-positive test response, the effect of postures for recording a postexercise electrocardiogram to the recovery process of ST depression was investigated in 26 women with nonischemic ST depression and in 14 patients with typical angina pectoris. Exercise tests were performed twice, and the postexercise electrocardiogram was recorded while standing during the first test and in the supine position during the second test. In the false-positive test, maximal ST depression occurred immediately after exercise and showed a rapid recovery process in the early recovery phase. However, ST depression persisted without complete recovery, or increased in the late recovery phase as long as subjects were kept standing. In contrast, ST depression returned to the control level when subjects changed to the supine position after exercising. This discrepant pattern in the recovery process of ST depression by changing postures was not observed in the true-positive test results. Changing postures for recording postexercise electrocardiograms could be helpful in differentiating a false-positive response from a true ischemic response.

Clinical significances of exercise induced negative U wave after anterior wall myocardial infarction.

心筋梗塞例でみられる運動負荷誘発性陰性U波 (NU) の意義を明確にする為, 前壁心筋梗塞例に限定し, 梗塞1ヶ月後負荷時前胸部誘導NU出現例〔NU (+) 群〕15例と非出現例〔NU (-) 群〕20例に分け, 冠動脈・左室造影像及び前壁における心筋血流分布を比較検討した.NU (+) 群全例左前下行枝に90%以上狭窄を, また完全閉塞例では比較的豊富な側副血行を認めたが, NU (-) 群では一定傾向はなかった.負荷Tl-201心筋シンチで前壁域に再分布を認め且つ左室造影像でその領域の壁運動温存があり, 生存心筋を多く含むと考えられる分画は, NU (+) 群に有意に多かった (p<0.001) .心電図上, NU出現は異常Q波を有する誘導に少なく, その周辺域からの誘導に多発した.NU出現時負荷左室造影で梗塞域壁運動の増悪化をみたが, dyskinesisを呈するには至らなかった.左前下行枝の血行再建後負荷時NUは消失, 心筋血流分布の正常化, 左室駆出率の増加をみた.以上よりNUは梗塞後も重篤冠狭窄を有するが, なおsalvage可能な生存心筋の存在を示す重要な心電図徴候であると考えられる.