What QRS duration may predict a risk of ventricular dysrhythmias in TCA overdose?
According to the cited reference, determination of the maximal limb-lead QRS duration predicts the risk of seizures and ventricular arrhythmias in acute overdose with tricyclic antidepressants. In this study, ventricular dysrhythmias were seen only with a WRS duration of 160ms or longer. In patients with QRS duration greater than 160 ms, there was a 14% incidence of ventricular dysrhythmias.
Boehnert MT, Lovejoy FH Jr. Value of the QRS duration versus the serum drug level in predicting seizures and ventricular arrhythmias after an acute overdose of tricyclic antidepressants. N Engl J Med. 1985 Aug 22;313(8):474-9. doi: 10.1056/NEJM198508223130804. PMID: 4022081