MYOCARDIAL BLOOD-FLOW HETEROGENEITY IN SHOCK AND SMALL-VOLUME RESUSCITATION IN PIGS WITH CORONARY STENOSIS

We analyzed the effects of shock and small-volume resuscitation in the presence of coronary stenosis on fractal dimension (D) and spatial co rrelation (SC) of regional myocardial perfusion. Hemorrhagic shock was induced and maintained for 1 h. Pigs were resuscitated with hypertoni c saline-dextran 60 [HSDex, 10% of shed blood volume (SBV)] or normal saline (NS; 80% of SBV). Therapy was continued after 30 min with dextr an (10% SBV). At baseline, D was 1.39 +/- 0.06 (mean +/- SE; HSDex gro up) and 1.34 +/- 0.04 (NS group). SC was 0.26 +/- 0.07 (HSDex) and 0.2 6 +/- 0.04 (NS). Left anterior descending coronary artery stenosis cha nged neither D nor SC. Shock significantly reduced D (i.e., homogenize d perfusion): 1.26 +/- 0.06 (HSDex) and 1.23 +/- 0.05 (NS). SC was inc reased: 0.41 +/- 0.1 (HSDex) and 0.48 +/- 0.07 (NS). Fluid therapy wit h HSDex further decreased D to 1.22 +/- 0.05, whereas NS did not chang e D. SC was increased by both HSDex (0.56 +/- 0.1) and NS (0.53 +/- 0. 06). At 1 h after resuscitation, SC was constant in both groups, and D was reduced only in the NS group (1.18 +/- 0.02). We conclude that he morrhagic shock homogenized regional myocardial perfusion in coronary stenosis and that fluid therapy failed to restore this.