Atypical P-wave morphology at baseline was associated with superior response to CRT at @ year with a larger reduction in left ventricular end-diastolic volume ( -@ @ % vs. -@ @ % , P = @ ) , left ventricular end-systolic volume ( -@ @ % vs. -@ @ % , P = @ ) , and left atrial volume ( -@ @ % vs. -@ @ % , P = @ ) , with a slightly larger absolute increase in left ventricular ejection fraction ( LVEF ) ( @ @ % vs. @ @ % , P = @ ) .