The negative inotropic effect of esmolol on isolated cardiac muscle

Abstract

Apart from being a beta adrenergic blocker esmolol also exerts a direct negative inotropic effect on cardiac muscle due to its inhibition of the calcium current during the action potential.

Landiolol has a less potent negative inotropic effect than esmolol in isolated rabbit hearts

“…The same was true for LVdP/dt max . To our knowledge, the mechanism of the inhibitory effects of esmolol on the circulation is still unknown [7]; however, the results of various studies make it unlikely that its circulatory inhibitory effects are due to its β-blocking effects, leading us to consider the possible involvement of other mechanisms, such as inhibition of the calcium current [18] or sodium current [19]. Esmolol has been used during cardiac surgery to induce minimal myocardial contraction while maintaining continuous normothermic perfusion to avoid ischemia, and the agent has been shown to provide myocardial protection equivalent to cardioplegia [20].…”

Effects of Resveratrol and Nebivolol on Isolated Vascular and Cardiac Tissues from Young Rats

“…At this stage, it is unclear as to the exact mechanism that may be at play behind the decrease in action potential duration after nebivolol exposure. A related study examining the negative inotropic effects of the β 1 -selective adrenoceptor blocker esmolol found similar results [32]. The authors proposed that the mechanism behind esmolol's effects was through the inhibition of the calcium current [32].…”

“…A related study examining the negative inotropic effects of the β 1 -selective adrenoceptor blocker esmolol found similar results [32]. The authors proposed that the mechanism behind esmolol's effects was through the inhibition of the calcium current [32]. The reduction in action potential duration by esmolol was also accompanied by a reduction in the force of the contraction [32].…”

“…The authors proposed that the mechanism behind esmolol's effects was through the inhibition of the calcium current [32]. The reduction in action potential duration by esmolol was also accompanied by a reduction in the force of the contraction [32]. This can be explained through the inhibition of the calcium current resulting in less calcium available intracellularly to initiate a contractile response.…”

Direct Effects of Esmolol and Landiolol on Cardiac Function, Coronary Vasoactivity, and Ventricular Electrophysiology in Guinea-Pig Hearts

“…Despite the usefulness of β 1 -adrenoceptor blockers in these settings, application of these drugs to septic patients or those in the perioperative period who are already hypotensive can exacerbate a further drop in blood pressure via direct actions on the cardiovasculature in addition to their β 1 -blocking effects. For example, esmolol has been shown to exert a potent negative inotropic action in both in vivo and in vitro studies, as well as inducing excessive hypotension in patients with poor cardiac function (5,6). Several independent studies comparing the negative chronotropic and inotropic effects of esmolol and landiolol revealed that esmolol had greater negative inotropic potency than landiolol (7 -9); however, the mechanisms underlying the disparity in negative inotropic potency between the two drugs are currently unknown.…”