Skip to Main Content

We have a new app!

Take the Access library with you wherever you go—easy access to books, videos, images, podcasts, personalized features, and more.

Download the Access App here: iOS and Android

ECG Findings

  • Tachycardia

  • QRS complex widening

  • QT prolongation

  • Prominent terminal R wave in aVR or V1

  • Prominent S in lead I

Pearls

  1. Tricyclic antidepressants (TCAs) produce their effects by several mechanisms. Anticholinergic effects may induce tachycardia, and sodium channel blockage may lead to QRS widening.

  2. The QRS widening seen in a TCA overdose has a nonspecific pattern and is typically unlike any bundle branch block morphology.

  3. ECG effects are rate dependent and become more pronounced with tachycardia and acidosis.

FIGURE 23.53A

Tricyclic Antidepressant Toxicity. (ECG contributor: Saralyn R. Williams, MD.)

FIGURE 23.53B

Prominent S wave in lead I (arrowhead) with prominent terminal R wave in aVR (arrow). The QRS complex is wide (double arrow), the QT interval is prolonged, and the patient is tachycardic.

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.