Heart rate curves during electroconvulsive therapy. Horizontal gray lines, baseline heart rate; dotted vertical lines, end of stimulation; broken vertical lines, end of motor seizure. (A) 39-year-old patient; RUL treatment, 151 mC; stimulus duration, 5.6 s. Baseline HR, 83 bpm; peak HR, 163 bpm; Trise, 9.3 s; Tmax, 19.2 s; Tbase, 54.0 s; Tdec, 58.5 s; motor seizure duration, 48 s. Gradual decline in heart rate at 25 s indicating either mitigation of sympathetic impact or activation of parasympathetic forces during the seizure and a second decline following the convulsive period. (B) 68-year-old patient; RUL stimulation, 195 mC, 7.5 s. Heart rate changed moderately from 77 to 107 bpm, and an abrupt decline at the end of the seizure was absent. Medical evaluation revealed an impaired atrioventricular conduction combined with a bundle branch block. (C) 43-year-old patient; RUL stimulation, 203 mC, 7.5 s. Asystole of 10.9 s duration; Trise, 13.9 s; motor seizure duration, 44 s. The electrode placement was switched to BF position in this patient to prevent cardiac standstill during stimulation. Doses and treatment technique remained otherwise unchanged (D). Trise, 2.9 s; motor seizure duration, 40 s; EEG seizure duration, 54 s. The post-ictal heart rate slowdown proceeded to an asystole of 6.2 s duration. Medical evaluation was unremarkable, and pharmacotherapy consisted of citalopram. (E) 76-year-old patient; BF treatment, 301 mC, 6.7 s. Trise, 2.6 s. The seizure end at 48 s was accompanied by a steep decline; the succeeding period of vagal dominance was marked by arrhythmia.