If inhibition in the atrioventricular node by ivabradine causes rate-dependent slowing of conduction and reduces ventricular rate during atrial fibrillation

Ivabradine's rate-dependent increase in A-H interval is highly correlated with VR during AF. As dominant frequency was unaltered, AV node conduction slowing during high nodal activation rates appears to be the main mechanism of ivabradine's VR reduction. If inhibition in the AV node may provide a promising target to slow VR during AF without depression in contractility.