ECG Case 135
A single agent overdose causing AV blockade, QRS widening, and QT prolongation.... but reports of death only if QRS > 200ms. Which medication is this?
Tag Sodium-Channel Blocker Toxicity
Phenytoin toxicity
Phenytoin intoxication can occur either with repeated supra therapeutic dosing or an acute overdose. Dose-dependent CNS depression occurs. Most presentations are benign and have good outcomes with supportive care. The main risk to patients is falling which can last days.
Sodium Channel Blocker Toxicity
AGENTS NB. phenytoin and sodium valproate do not usually present with features of sodium channel blockade in overdose. CLINICAL FEATURES INVESTIGATIONS SPECIFIC MANAGEMENT AND TRIGGERS FOR INTERVENTION References and Links
Tricyclic Antidepressant Toxicity
Tricyclic Antidepressants (TCA) are weak bases (pKa 8.5) that can cause life-threatening sodium channel toxicity
ECG Case 056
Middle-aged patient presenting with drowsiness. Brief seizure in ED. BP unrecordable. Interpret the ECG.
ECG Case 055
Middle-aged patient presenting with drowsiness. BP 85/50. Pupils dilated. Interpret the ECG. TCA overdose, pseudo Brugada
Tricyclic Overdose
A review of the ECG features seen in TCA overdose, which occur due to a combination of sodium channel blockade and antimuscarinic effects