Figure 2. Mean pain perception in subclasses estimated by CART analysis (n = 84 patients). SHOCKS: number of shocks. ANXIETY: anxiety SCL-90 (0: no, 1: yes). EMMW: electromyogram magnitude (in µV). EMHAB: electromyogram habituation (in µV). Mean pain perception in end subclasses: Subclass 1 (SHOCKS = 1 and EMMW 4.15, n = 12): 21.9 (95% CI, 4.6–39.1). Subclass 2 (SHOCKS = 1 and EMMW >4.15, n = 14): 51.7 (95% CI, 34.2–69.3). Subclass 3 (SHOCKS >1 and ANXIETY 7 and EMMW 3.4, n = 11): 36.0 (95% CI, 19.0–53.0). Subclass 4 (SHOCKS >1 and ANXIETY 7 and EMMW >3.4 and EMHAB >0.21, n = 17): 51.1 (95% CI, 35.9–66.2). Subclass 5 (SHOCKS >1 and ANXIETY 7 and EMMW >3.4 and EMHAB 0.21, n = 18): 71.2 (95% CI, 61.6–80.9). Subclass 6 (SHOCKS >1 and ANXIETY >7, n = 12): 74.8 (95% CI, 60.5–89.2).