Figure 6
Calcium analysis and decay constant validation. (a) CaT50 map from murine atrium as measured from time of maximum upstroke velocity to 50% decay, illustrated in red in region of interest signal (CaT50upstroke). Also shown is the measurement of CaT50 from peak amplitude in region of interest (blue, CaT50peak map in Supplementary Fig. VA). (b) Map of decay constant, τ, from the same atrium. Map shows calculation of τ by fitting of exponential decay points between 30% and 90% decay from peak (τ30–90), illustrated for the regional signal in blue. Also shown is calculation of τ between 10% decay and baseline (red, τ10-BL map in Supplementary Fig. VD). (c) Representative τ maps (τ30–90) from murine left atria as pacing frequency is increased. (d) Data showing shortening of mean τ across the atria with increased pacing frequency. (e) Data showing decrease of τ heterogeneity (measured as standard deviation of mean τ across individual atria) across the atria with increased pacing frequency. Data displayed as mean ± standard error, n = 5. P < 0.05, One-Way ANOVA followed by Bonferroni multiple comparison test against 3 Hz pacing.
