PRESERVATION OF REGIONAL MYOCARDIAL-FUNCTION AND MYOCARDIAL OXYGEN-TENSION DURING ACUTE-ISCHEMIA IN PIGS - COMPARISON OF SELECTIVE SYNCHRONIZED SUCTION AND RETROINFUSION OF CORONARY VEINS TO SYNCHRONIZED CORONARY VENOUS RETROPERFUSION

Objectives. The efficacy of selective synchronized suction and retroin fusion of coronary veins was compared with synchronized coronary venou s retroperfusion in preventing ischemic reduction of regional myocardi al function and myocardial oxygen tension. Background. Because incompl ete protection by synchronized coronary venous retroperfusion during i schemia might result from nonselective retroinfusion and only passive drainage of the veins, a suction device was added to a retroinfusion s ystem. Methods. Regional myocardial function (ultrasonic crystals) and myocardial oxygen tension (polarographic electrodes) were studied in 30 pigs during 10 min occlusion of the left anterior descending corona ry artery (ischemia), followed by reperfusion. During ischemia, group A (n = 10) was supported by selective synchronized suction and retroin fusion; group B (n = 10) was supported by synchronized coronary venous retroperfusion, and group C (n = 10) was not supported by retroinfusi on. Results. In group A, subendocardial segment shortening decreased f rom 21 +/- 4% (mean +/- SD) before ischemia to 11 +/- 5% during ischem ia. In contrast, systolic dyskinesia was observed in group B (-2 +/- 4 %, p < 0.001) and group C (-2 +/- 5%, p < 0.001). During ischemia, the decrease in intramyocardial oxygen tension was less pronounced in gro up A (41 +/- 15 vs. 27 +/- 12 mm Hg) than in group B (40 +/- 10 vs. 19 +/- 10 mm Hg, p = 0.1) or group C (33 +/- 11 vs. 12 +/- 8 mm Hg, p = 0.002). During ischemia, myocardial surface oxygen tension was preserv ed >0 mm Hg only in group A. Conclusions. Preservation of regional myo cardial function and myocardial oxygen tension was Substantially highe r by selective synchronized suction and retroinfusion of coronary vein s than by synchronized coronary venous retroperfusion in pigs.