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 retroinfusion of coronary veins was compared with synchronized coronary venous retroperfusion in preventing ischemic reduction of regional myocardial function and myocardial oxygen tension. Background. Because incomplete protection by synchronized coronary venous retroperfusion during ischemia might result from nonselective retroinfusion and only passive drainage of the veins, a suction device was added to a retroinfusion system. 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 coronary artery (ischemia), followed by reperfusion. During ischemia, group A (n = 10) was supported by selective synchronized suction and retroinfusion; group B (n = 10) was supported by synchronized coronary venous retroperfusion, and group C (n = 10) was not supported by retroinfusion. Results. In group A, subendocardial segment shortening decreased from 21 +/- 4% (mean +/- SD) before ischemia to 11 +/- 5% during ischemia. 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 group 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 preserved >0 mm Hg only in group A. Conclusions. Preservation of regional myocardial function and myocardial oxygen tension was Substantially higher by selective synchronized suction and retroinfusion of coronary veins than by synchronized coronary venous retroperfusion in pigs.