Fig. 1.

A. T-wave alternans from the ECG of an unrestrained, conscious, FAIL animal. The T-wave shows a long (L), short (S) pattern. B Discordant alternans in an isolated heart from a FAIL animal revealed by optical mapping. Differences between beat 1 and 2 in zones a and b are out of phase for both AP amplitude and AP duration. C. Increased APD and dispersion of APD in the RV of a FAIL animal compared to a CON animal. D Difference in APD₈₀ between RVOT and mid-RV at 5 Hz. In CON hearts APD in the RVOT region was shorter than the mid-RV but longer in MCT treated hearts (***P < 0.001 N = 11 CON and 9 MCT hearts), thus APD remodelling was greater in the RVOT than the mid-RV. E APD restitution was significantly steeper in FAIL than CON hearts or hearts from animals with stable hypertrophy (HYP). A, B, C and E modified from (Benoist et al., 2012).