Class II: Beta adrenergic blockers
The drugs in this class suppress adrenergic mediated ectopic activity. The members of the group like propranolol block the beta receptors of the cardiac tissue. It decreases slope of Phase IV depolarization and automaticity in SA node.
Propranolol is useful in treating sinus tachycardia, extrasystoles provoked by exercise or emotion. Sotalol is beta blocker with also Class III activity.
Esmolol is a short acting drug for emergency control of ventricular rate.