Bradycardia in toluene poisoning

Background: Tachyarrhythmias are the classical manifestation of toluene cardiotoxicity, The presumed mechanism is sensitization of the myocardium to the potential arrhythmogenic effect of endogenous catecholamines, occasionally resulting in fatality. Bradyarrhythmias have been repeatedly shown in animal models, but have been reported only once in a human. Case Reports: Two patients with toluene intoxication presented with severe sinus bradycardia. One patient had also atrial-ventricular dissociation. In both cases cardiac rhythm returned to normal within several hours. Conclusion: We suggest that the spectrum of cardiotoxic symptoms associated with toluene intoxication in humans includes bradyarrhythmias as well as tachyarryhthmias.