Clinical perspectives of heart rate slowing for coronary event reduction and heart failure.

Heart rate is a major determinant of myocardial oxygen consumption. There is ample evidence of an association between high heart rate and poor outcome in numerous clinical settings. Experimental studies in monkeys have shown a link between increased heart rate and development of atherosclerosis. In the clinical setting, increased heart rate has been found associated with coronary plaque rupture. A causal relationship is further supported by the fact that Beta-blockers have a well-documented efficacy after myocardial infarction, although the other properties of these agents may also participate in their protective effect. Beyond the potential benefits of heart rate lowering in patients with coronary artery disease, medications capable of decreasing heart rate without altering left ventricular function, such as the I(f) current inhibitor ivabradine, might prove particularly helpful in patients with chronic heart failure associated with coronary artery disease, but also in heart failure without systolic dysfunction, or in patients needing inotropic support for acute heart failure.