The main pharmacological effects of digoxin are on the heart. Extracardiac effects are responsible for some of the therapeutic and many of the adverse effects (see above). It exerts a mechanical effects as it increases myocardial contractility; however, the duration of the contractile response is just slightly increased. Overall, the heart rate is decreased, while blood pressure is increased resulting in an net increase in stroke volume, leading to increased tissue perfusion. This causes the myocardium to work more efficiently, with optimised haemodynamics and the ventricular function curve is improved.