Figure 3.

Two-dimensional electroanatomic colormaps reveal comparable substrate. Epicardial monophasic action potential amplitude colormaps from 3 randomly selected rats, each representing its respective group namely SHAM, 6-wk heart failure (HF), or 10-wk HF. The colormaps reveal a normal epicardium in SHAM, with a single area of red highlighting the sensitivity of monophasic action potential amplitude (MAPA) in characterizing the epicardium. The 6-wk HF colormap shows gross MAPA defects on the right, which corresponds to the left coronary artery myocardial territory. The HF-10-wk map exhibits maintenance of the electrical infarct with a widening of the border region but improvement in MAPA millivoltage in the scar. Although scar burden is different between these 2 randomly selected HF rats representing the 6-wk end point and the 10-wk end point, the qualities of the substrates are similar and the hemodynamic and echocardiographic group averages support the notion that the degree of myocardial infarction-mediated HF was comparable between the 2 groups.