First-Degree Atrioventricular Block Medication

Updated: Jul 27, 2022
  • Author: Jamshid Alaeddini, MD, FACC, FHRS; Chief Editor: Jose M Dizon, MD  more...
  • Print

Medication Summary

Use of medication is not indicated for treatment of asymptomatic first-degree atrioventricular (AV) block. However, in patients with severe bradycardia or those with the possibility of progression to higher-degree AV block, medications (eg, atropine, isoproterenol) can be used in anticipation of insertion of a cardiac pacemaker.


Anticholinergic Agents

Class Summary

Parasympathetic blockade shortens the PR interval by improving AV nodal conduction.

Atropine IV/IM (AtroPen)

Atropine increases heart rate through vagolytic effects, causing increase in cardiac output.



Class Summary

Isoproterenol infusion can be used to shorten AV conduction time. Isoproterenol has chronotropic as well as inotropic effects, which result in an increase in cardiac output.

Isoproterenol (Isuprel)

Isoproterenol has beta1- and beta2-adrenergic receptor activity. It binds the beta-receptors of the heart, smooth muscle of bronchi, skeletal muscle, vasculature, and the alimentary tract. It has positive inotropic and chronotropic actions.