虚血性心疾患におけるhigh risk patientsの検出—負荷心筋スキャン，負荷心プールスキャンの併用による

Noninvasive identification of high risk coronary artery disease paticnts:The role of rest-exercise LVEF and transient-persistent defect

　虚血性心疾患において，虚血の検出およびその重症度判定は，診断のみならず治療方針の決定に重要である。負荷心筋スキャンおよび負荷心プールスキャンは，負荷心電図以上に冠動脈病変の検出に関するsensitivity，specificityが高いことから，非観血的検査法として近年汎用されている^1,2）。両検査は虚血の検出に加え，前者では梗寒・虚血部位の同定・鑑別に，後者では心機能，局所壁運動異常の検出から心予備能の評価に有用なことが認められている。著者らも，それぞれの検査法を用いた虚血の検出について既に報告してきた^3,4）。とりわけ虚血性心疾患において，内科，外科療法を含めた治療方針の決定のために，両検査法によるhigh risk patientsの検出は重要である。そこで本研究では，虚血の検出に加え，両検査法を用いて虚血の重症度判定について，冠動脈造影を施行している心筋梗塞40例，狭心症30例について検討したので報告する。

An important role of stress thallium imaging (TI) and stress radionuclide ventriculography (RNV) for evaluation of coronary artery disease CAD) is detection of high risk patients such as left main or triple vessel disease noninvasively. In this study, these method were performed in 70 cases of CAD MI 40 cases, AP 30 cases) who underwent coro-nary angiography. In I1 cases of CAD, substantial decline of LVEF during exercise from rest ( < 10 %) indicated AP with multivessel or proximal LAD occlusion, and anterior MI with multivessel disease. By combined study with T1 and RNA, patients with transient defect (TD) had more ischemic LV re-sponse in comparing with only presistent defect (PD). The combination cases of TD + PD were poor LV functional reserve which expressed MI with AP. In the patients which low LVEF and large PD at resting, which expressed large MI, rest and exercise LVEF was no increased but lung uptake of TI and lung heart Tc-RBC ratio wereincreased significantly in comparing with normal resting LVEF.

In conclusion, the identification of high risk CAD patients by T1 and RNA method were as follows. In RNA study, 1. low rest and exercise LVEF, 2. LVEF<10% from rest to exercise, while in Ti study, 1. large PD or large TD, 2. TD+ PD, and 3. in both methods, lung uptake of thallium and lung heart Tc-RBC ratio. In both study, resting LVEF and Tl size had important role in prior MI cases in addition to exercise study, while in AP cases, exercise LVEF and TD is more significant predictor of high risk patient.