Figure 3: Brief Myocardial Ischemia Elicits a Delayed Rise in Serum cTnI

Serum cTnI concentrations were low, but detectable, at baseline and did not exceed the 99th percentile of normal animals (38 ng/l) during the first 30 min of reperfusion following a 10-min LAD occlusion. However, cTnI concentrations in coronary venous and systemic venous blood rose above the 99th percentile value 60 min after reperfusion and continued to rise at subsequent time points, ultimately increasing by ∼100-fold versus baseline levels 24 h post-reperfusion. Because cTnI concentrations were not normally distributed, nonparametric testing (Friedman test) was used to evaluate the trend in cTnI values after reperfusion, with post-hoc paired Wilcoxon sign rank testing to determine where significant differences were observed between specific time-points. Note the use of a logarithmic scale on the y-axis. n = 5 at 10 min, 120 min, 180 min, and 24 h; n = 10 at all other time points. cTnI = cardiac troponin I; LAD = left anterior descending coronary artery.