Fig. 7: Response of force and calcium to isoprenaline (ISO).

a Normalized average contraction force and calcium and force-calcium loops of human myocardial slices in the presence of DMSO (0.1%, n = 4 patients, 4 slices) or ISO (0.5 µM, n = 4 patients, 4 slices) at 0.5 Hz pacing frequency. b Relative changes of amplitude, Ton, and tau in force and calcium transients of myocardial slices after treatment with DMSO or ISO (amplitude, n = 4 patients, 4 slices; Ton and tau, n = 5 patients, 5 slices in force and calcium, respectively). Data are depicted as means ± SEM. Statistical differences were calculated with paired Student t-tests. A p < 0.05 was defined as the significance cutoff.