The Relation between Collateral Circulation and $^{99m}Tc$-MIBI Heart SPECT

심근경색에서 측부순환 유무에 따른 $^{99m}Tc$-MIBI 심근 SPECT 소견

The coronary collateral vessels have revealed their significance in terms of reduction of infarct size, preservation left ventricular function, and prevention of left ventricular aneurysm in patients with myocardial infarction. The purpose of this study were to evaluated the relation between collateral circulation and $^{99m}Tc$-MIBI Heart SPECT in patient with acute myocardial infarction and their clinical significance. The fifty six MI patients with antegrade TIMI perfusion grade 0 and 1 were studied. The patients were classified into two groups; Group I inclueded 30 patients with grade 2, 3 Collateral flow. Group II inclueded 26 patients with grade 0, 1 Collateral flow. Collateral filling were graded from 0 to 3: 0- none, 1- Filling of side branch only, 2- Partial filling of the epicardial segment, 3- Complete filling of epicardial segment. Clinical variables, left ventricular function, $^{99m}Tc$-MIBI Heart SPECT were analyzed with angiographic finding. Results were following: 1) Collateral visualization was found to be greater in patient with involvement of right coronary artery (RCA). The collateral development site of infarct related artery was RCA 15 cases, left anterior descending artery (LAD) 10 cases, left circumflex artery (LCX) 5 cases, and the collateral circulation from LAD to RCA was 13 cases (40.6%). 2) There was a tendency to be decreased in peak CK activity with group I. 3) The presence of good collateral channels was more frequently $^{99m}Tc$-MIBI reversible perfusion defect (83.4% vs 15.3%, p<0.05). 4) No differences of left ventricular end diastolic volume (LVEDV), left ventricular end systolic volume (LVESV), ejection fraction (EF) were noted between group I and group II. The presence of good collateral channels did affect the frequency of occurrence of $^{99m}Tc$-MIBI reversible perfusion defect.

심근경색후 측부순환의 존재는 심근경색의 크기를 감소시키고 생존가능한 심근의 양을 늘려 심근기능의 보존에 기여하며 심실류 혈성을 예방하는 것으로 알려져 있다. 본 연구에서는 심근경색후 측부순환의 분포와 측부순환에 따른 심근 SPECT소견을 알아보고자 시행하였다. 급성심근경색으로 진단된 환자중 2주내에 관동맥 조영술을 시행하여 TIMI grade 0, 1인 환자 56예를 대상으로 하여 측부순환이 좋은 I군과 측부순환이 나쁜 II군으로 분류하여 양군간의 임상양상 및 좌심실기능과 심근 SPECT 소견을 조사하여 다음의 결과를 얻었다. 1) 경색관련 동맥에로의 측부순환은 우관동맥 15예, 좌전하행동맥 10예, 좌회선동맥 50예 순이 었다. 2) 측부순환 경로는 좌전하행동맥에서 우관동맥으로 13예(40.6%), 우관동맥에서 좌전하행동맥으로 9예(28.1%)로 우관동맥과 좌전하행동맥 사이에 흔하였다. 3) 최고 CK 활성도는 I군에서 낮은 경향이 있었다. 4) $^{99m}Tc$-MIBI 심근 SPECT상 측부순환로가 발달한 I군에서 경색부위 가역성 관류결손 부위 빈도가 높았다 (83.4% vs 15.3%, p<0.05). 5) LVEDV, LVESV, EF는 두 군간에 차이가 없었다. 관동맥 조영술상 측부순환로의 존재는 $^{99m}Tc$-MIBI 심근 SPECT의 가역성 관류결손 부위와 유의한 연관성이 있었으며, 심근 SPECT는 기능적 측부순환을 관찰하는데 유용한 검사로 생각된다.