Myocardial blood flow heterogeneity in shock and small-volume resuscitation in pigs with coronary stenosis.

Myocardial blood flow heterogeneity in shock and small-volume resuscitation in pigs with coronary stenosis. J. Appl. Physiol. 83(6): 1832-1841, 1997.-We analyzed the effects of shock and small-volume resuscitation in the presence of coronary stenosis on fractal dimension (D) and spatial correlation (SC) of regional myocardial perfusion. Hemorrhagic shock was induced and maintained for 1 h. Pigs were resuscitated with hypertonic saline-dextran 60 [HSDex, 10% of shed blood volume (SBV)] or normal saline (NS; 80% of SBV). Therapy was continued after 30 min with dextran (10% SBV). At baseline, D was 1.39 +/- 0.06 (mean +/- SE; HSDex group) and 1.34 +/- 0.04 (NS group). SC was 0.26 +/- 0.07 (HSDex) and 0.26 +/- 0.04 (NS). Left anterior descending coronary artery stenosis changed neither D nor SC. Shock significantly reduced D (i.e., homogenized perfusion): 1.26 +/- 0.06 (HSDex) and 1.23 +/- 0.05 (NS). SC was increased: 0.41 +/- 0.1 (HSDex) and 0.48 +/- 0.07 (NS). Fluid therapy with HSDex further decreased D to 1.22 +/- 0.05, whereas NS did not change 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 hemorrhagic shock homogenized regional myocardial perfusion in coronary stenosis and that fluid therapy failed to restore this.