Figure 4. Microscopic EC coupling is compromised in HFrEF but enhanced in HFpEF.
A, individual Ca2+ sparks triggered by depolarisation to 0 mV resolved using ultra‐high‐speed resonant confocal line scanning in fluo‐4‐loaded patch‐clamped cardiomyocytes. Dashed line indicates onset of depolarisation. B, histograms of spark latencies in control (blue), HFrEF (black) and HFpEF (red). C–E, mean (+ SD) spark probability, spark latency variability (plotted as standard deviation of latency), and spark latency (n = 13, 14 and 19 cells from 6, 3 and 5 control, HFrEF and HFpEF rats, respectively). Statistics are calculated by one‐way ANOVA. [Color figure can be viewed at wileyonlinelibrary.com]