Japanese
Title心筋梗塞後のSilent ischemiaの検出について : 運動負荷心電図と心筋シンチグラフィでの対比検討
Subtitle原著
Authors山岸隆*, 松田泰雄*, 佐藤晃*, 市岡隆志*, 古谷雄司*, 原口正彦*, 尾崎正治*, 楠川禮造*, 前田準也**, 中司昌美**, 河野隆任**, 吉永憲正**
Authors(kana)
Organization*山口大学医学部第二内科, **徳山中央病院内科
Journal核医学
Volume28
Number3
Page261-269
Year/Month1991/3
Article原著
Publisher日本核医学会
Abstract「要旨」116名の陳旧性心筋梗塞患者を対象に, 心筋梗塞後のSilent ischemiaの検出について運動負荷心電図と心筋シンチグラフィーを用い対比検討した. タリウムSPECT画像を20分画した後に一過性心筋虚血の指標として再分布スコアを求めた. 20名の正常者より得られた再分布スコアの2標準偏差以上を呈する場合を一過性虚血ありと判定した. 心筋梗塞患者116名のうち47名に一過性虚血がみられ, そのうち25名 (53%) が心電図陽性所見を示した. また一過性虚血のなかった69名のうち14名 (20%) にも心電図陽性所見がみられた. したがって, 116名での負荷心電図による一過性虚血検出の感度53%, 特異度80%, 偽陽性率20%, 偽陰性率47%, 診断精度69%となった. さらに116名を胸痛と心電図変化の有無により4グループに分類した. 14名が心電図変化と同時に胸痛を有し, 全例に一過性虚血がみられた. 心電図変化を有するが胸痛のない, いわゆる心電図診断でのSilent ischemia群25名のうちの44%が一過性虚血を呈した. 胸痛はあるが心電図変化のない, 従来より心電図診断の難しい群7名のうちの43%が一過性虚血を有した. また胸痛も心電図変化も示さない70名においても27%の患者に一過性虚血が証明された. したがって, 心筋梗塞後の運動負荷試験において心電図変化と同時に胸痛を伴えば, ほとんど全例に一過性虚血がみられた. しかし, 心電図変化のみの時にはタリウムイメージでの一過性虚血の出現頻度は44%であり, かなりの率で疑陽性や疑陰性例が含まれていた. すなわち, 心筋梗塞後の心電図診断でのSilent ischemiaの判定には限界があり注意が必要と思われた.
Practice臨床医学：一般
KeywordsSilent myocardial ischemia, prior myocardial infarction and thallium scintigraphy.
English
TitleReliability of the Exercise ECG in Detecting Silent Ischemia in Patients With Prior Myocardial Infarction
SubtitleOriginal Articles
AuthorsTakashi YAMAGISHI*, Yasuo MATSUDA*, Akira SATOH*, Takashi ICHIOKA*, Yuhji FURUTANI*, Masahiko HARAGUCHI*, Masaharu OZAKI*, Reizo KUSUKAWA*, Junya MAEDA**, Masami NAKATSUKA**, Takatou KOHNO**, Kensei YOSHINAGA**
Authors(kana)
Organization*The Second Department of Internal Medicine, Yamaguchi University School of Medicine, **The Department of Internal Medicine, Tokuyama Central Hospital
JournalThe Japanese Journal of nuclear medicine
Volume28
Number3
Page261-269
Year/Month1991/3
ArticleOriginal article
PublisherTHE JAPANESE SOCIETY OF NUCLEAR MEDICINE
Abstract[Summary] To assess the reliability of the exercise ECG in detecting silent ischemia, ECG results were compared with those of stress-redistribution thallium-201 single-photon emission computed tomography (SPECT) in 116 patients with prior myocardial infarction and in 20 normal subjects used as a control. The LV was divided into 20 segmental images, which were scored blindly on a 5-point scale. The redistribution score was defined as thallium defect score of exercise subtracted by that of redistribution image and was used as a measure of amount of ischemic but viable myocardium. The upper limit of normal redistribution score (= 4.32) was defined as mean +2 standard deviations derived from 20 normal subjects. Of 116 patients, 47 had the redistribution score above the normal range. Twenty-five (53%) of the 47 patients showed positive ECG response. Fourteen (20%) of the 69 patients, who had the normal redistribution score, showed positive ECG response. Thus, the ECG response had a sensitivity of 53% and a specificity of 80% in detecting transient ischemia. Furthermore, the 116 patients were subdivided into 4 groups according to the presence or absence of chest pain and ECG change during exercise. Fourteen patients showed both chest pain and ECG change and all these patients had the redistribution score above the normal range. Twenty-five patients showed ECG change without chest pain and 11 (44%) of the 25 patients had the abnormal redistribution. Three (43%) of 7 patients who showed chest pain without ECG change had the abnormal redistribution score. Of 70 patients who had neither chest pain nor ECG change, 19 (27%) had the redistribution score above the normal range. Thus, limitations exist in detecting silent ischemia by ECG in patients with a prior myocardial infarction, because the ECG response to the exercise test may have a low degree of sensitivity and a high degree of false positive and false negative results in detecting silent ischemia.
PracticeClinical medicine
KeywordsSilent myocardial ischemia, prior myocardial infarction and thallium scintigraphy.

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