class IV drugs in atrial fibrillation
Last reviewed 05/2021
Drugs such as verapamil and diltiazem increase the refractory period of the atrioventricular node and so control the ventricular response to atrial fibrillation.
Disadvantages of verapamil include:
- a lower rate of conversion to sinus rhythm than with class IV or class I drugs
- a danger of malignant ventricular arrhythmias if there is underlying Wolff-Parkinson-White syndrome
- a lack of efficacy in paroxysmal atrial fibrillation