Sodium channel blocker toxicity

Terminal right axis deviation of the QRS complexes
- Larger wide S wave in leads I & V6
- Taller R wave in aVR
- Tall R wave in V1 (Brugada pattern)
Widening of the QRS complex (intraventricular conduction delay)
Sinus Tachycardia
Prolonged QT
- (usually no TdP as tachycardic)
  Treatment: Sodium bicarbonate; avoid medications like amiodarone, lidocaine, and procainamide which will worsen toxicity

TCA
cocaine: Class 1c agent

References