Figure 2: HF Hearts Have an Increased Susceptibility to APD-ALT, Which Is Prevented by RDN

(A) Representative action potential tracings at 333-ms and 130-ms pacing cycle length from CTL, HF, and HF+RDN hearts are shown. Significant APD alternans (APD-ALT) is seen in the HF heart (middle panel), but not in the CTL (upper panel) and HF+RDN (lower panel) hearts. (B) Summary data demonstrating the relationship of pacing rate (PR) and APD alternans from CTL, HF, and HF+RDN hearts are shown. In HF hearts, more APD-ALT is observed at each PR tested, and HF produces a leftward shift in APD-ALT to PR relationship, which is prevented by RDN (HF+RDN). *p < 0.05 HF versus CTL group. #p < 0.05 HF+RDN versus HF group. bpm = beats/min; L = long action potential duration; S = short action potential duration; other abbreviations as in Figure 1.