<prompt> Ivabradine is indicated in the management ofCongestive hea failureCardiomyopathyAngina pectorisIrritable bowel syndrome  <response>: Ivabradine This pure hea rate lowering antianginal drug has been introduced recently. mech of action:- The only significant action of ivabradine is blockade of cardiac pacemaker sino-atrial cell f channels, which are funny cation channels that open during early pa of slow diastolic phase 4 depolarization. The resulting inward current If determines the slope of phase 4 depolarization. Selective blockade of If current by ivabradine results in hea rate reduction without any other electrophysiological or negative inotropic or negative lucitropic slowing of myocardial relaxation effect. Hea rate reduction decreases cardiac O2 demand and prolongation of diastole tends to improve myocardial perfusion O2 supply. Accordingly, in clinical trials, ivabradine has been found to improve exercise tolerance in stable angina and reduce angina frequency. Indications:- Used in chronic stable angina in patients with sinus rhythm. Ref:- kd tripathi;pg num:-554 