| Popis: |
We developed a radioimaging technique for measuring regional myocardial blood flow (rMBF) in 5 mm2 myocardial tissue using canine closed-chest models. RMBF was measured in three groups: (1) total occlusion of left anterior descending (LAD) coronary artery with microfibrillar collagen, (2) fixed stenosis of LAD with angioplasty balloon, and (3) comparison of clinical dose response of adenosine (AD) and dipyridamole (DP) on rMBF. In these studies, rMBF in every 5 mm2 tissue was measured throughout the epicardium and endocardium. In groups 1 and 2, rMBF was also measured during adenosine-induced coronary hyperemia (ADICH). In group 1 (n = 7), rMBF measured at 6 hours post-LAD occlusion in epicardial infarct center (IC), peri-infarct (PI) and normal zone (NZ) were 17 +/- 7, 55 +/- 8, and 132 +/- 12 ml/min/100 tissue, respectively. The area and location of infarct seen in TTC staining matched with rMBF images. During ADICH, the corresponding rMBF were 16.2 +/- 13.9, 98.3 +/- 53.0, and 226.0 +/- 103.6 ml/min/100 g tissue, respectively. RMBF measured during ADICH in group 2 (n = 4) in areas of LAD stenosis (LS), surrounding stenosis (SS), and no stenosis (NS) were 120 +/- 58, 249 +/- 123, and 432 +/- 181 ml/min/100 gm tissue, respectively. In group 3, rMBF measured during 3 min into 0.14 mg/kg/min adenosine infusion in areas perfused by LAD, circumflex (CX) and right coronary artery (RCA) were 244 +/- 22, 238 +/- 19, and 215 +/- 19 ml/min/100 g tissue, respectively.(ABSTRACT TRUNCATED AT 250 WORDS) |
