Peak velocity in the LVOT was significantly decreased compared to baseline for both drugs ; however , the effect was more prominent with atenolol ( mean reduction 2.53 m/s ; 95 % CI 2.07-3 .13 m/s ) compared to ivabradine ( mean reduction 0.32 m/s ; 95 % CI -0.04 to 0.71 m/s ; P < .0001 ) .