Esmolol is a very short
acting, cardioselective beta-adrenergic receptor
i.v. administration is
used for rapid beta-receptor blockade in
treatment of atrial fibrillation with high
ventricular following rates.
Antiarrhythmic effects are due mainly to
beta-adrenergic receptor blockade. Normally,
sympathetic drive results in increased in Ca2+
Increased sympathetic tone also increases
phase 4 depolarization (heart rate goes up), and
increases DAD (delayed afterdepolarizations) and
EAD (early afterdepolarization) mediated
arrhythmias. These effects are blocked by
beta-adrenergic receptor blockers.
Beta-adrenergic receptor blockers
increase AV conduction time and increase AV nodal
refractoriness, thereby helping to terminate
nodal reentrant arrhythmias.