Esmolol

Esmolol, sold under the brand name Brevibloc, is a cardioselective beta1 receptor blocker with rapid onset,[1] a very short duration of action, and no significant intrinsic sympathomimetic or membrane stabilising activity at therapeutic dosages. It is a class II antiarrhythmic.[2] Esmolol decreases the force and rate of heart contractions by blocking beta-adrenergic receptors of the sympathetic nervous system, which are found in the heart and other organs of th... [wikipedia]