Hemodynamic correlates of late diastolic posterior motion of the aortic root.

Motion of the posterior aortic root on echocardiography is related to left atrial volume changes. Early diastolic posterior motion of the aortic root reflects both LA emptying and filling and has been measured as the atrial emptying index. To study late diastolic motion of the aortic root, we measured the slope of posterior motion of the aortic root after left atrial systole (following the P wave of the ECG) in 25 subjects without heart disease (Group 1), in 15 patients with left ventricular hypertrophy due to pressure overload (Group 3) with mitral stenosis. The aortic root slope measured (mean +/- SEM) 58.0 +/- 1.9 mm./sec. in Group 1, 50.6 +/- 4.5 mm./sec. in Group 2 (NS vs 1) and 28.8 +/- 4.5 mm./sec. in Group 3, (p < 0.01 vs 1 or 2). In 16 patients (four in Group 1 and 12 in Group 2) studied at catheterization, an inverse correlation ( r = -0.74, p < 0.01) was found between the aortic root slope (over a range of 30 to 73 mm./sec.) and left ventricular late diastolic chamber stiffness measured with simultaneous left ventricular echo and high-fidelity pressure recordings. No correlation was found between this slope and either left atrial size, total aortic root excursion, left ventricular pressure pre "A" wave, height of the A wave, end-diastolic pressure, or the atrial contribution to left ventricular filling. Therefore, the aortic root slope in late diastole is decreased in mitral stenosis and in the absence of mitral stenosis, it appears to be related to late diastolic properties of the left ventricle.