Which medications in the drug class Antiarrhythmics, Class IA are used in the treatment of Ventricular Tachycardia?

Updated: Dec 05, 2017
  • Author: Steven J Compton, MD, FACC, FACP, FHRS; Chief Editor: Jeffrey N Rottman, MD  more...
  • Print

Antiarrhythmics, Class IA

Class IA antiarrhythmics increase the refractory periods of the atria and ventricles. Myocardial excitability is reduced by an increase in threshold for excitation and inhibition of ectopic pacemaker activity.

Procainamide (Procanbid, Pronestyl, Pronestyl [SR])

Procainamide is a class IA antiarrhythmic used for VT that is refractory to defibrillation and epinephrine. It is indicated for ventricular arrhythmias such as sustained VT. Procainamide is available only in IV form and is rarely used, because of hypotension and proarrhythmia risk. However, procainamide still maintains a specific niche as the drug of choice for management of stable preexcited atrial fibrillation. Its use is contraindicated by the presence of QT prolongation or congestive heart failure.

Quinidine (Quinidex, Quinora, Quinalan, Cardioquin)

Quinidine is a class IA antiarrhythmic that depresses myocardial excitability and conduction velocity. It is indicated for sustained VT but is rarely used, because of proarrhythmia risk. It still maintains a specific niche for VT suppression in specific patients with Brugada syndrome.

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!