Urquhart ML, Ramsey FM, Royster RL, Morell RC, Gerr P. Heart rate and rhythm following an edrophonium/atropine mixture for antagonism of neuromuscular blockade during fentanyl/N2O/O2 or isoflurane/N2O/O2 anesthesia. Anesthesiology. 1987 Oct; 67(4):561-5.