[Preload dependence of atrial contribution: correlation with left ventricular endo-diastolic wall stress].

The correlation between left ventricular end-diastolic wall stress (sigma ed) and atrial contribution was investigated using echocardiography including the pulsed Doppler method and cardiac catheterization with cineangiography in 21 patients with coronary artery disease, 4 with hypertensive heart disease, 3 with hypertrophic cardiomyopathy, 3 with dilated cardiomyopathy, 4 with aortic regurgitation, and 10 normal subjects. The ratio of peak velocities (A/R) in the rapid filling phase (R) and atrial contraction phase (A) was used as the index of atrial contribution. Left ventricular end-diastolic stiffness (delta P/delta V) was calculated by the ratio of increases in left ventricular pressure and volume during the atrial contraction phase. The correlations between A/R and sigma ed, mean pulmonary capillary wedge pressure (m-PCWP), and left ventricular end-diastolic pressure (LVEDP) were analyzed in the 35 patients. Correlations between delta P/delta V and sigma ed and A/R were also analyzed. A/R was inversely correlated with sigma ed (r = -0.75), m-PCWP (r = -0.62) and LVEDP (r = -0.59), suggesting that A/R is influenced significantly by preload. A/R was also inversely correlated with delta P/delta V (r = -0.72). delta P/delta V was significantly correlated with sigma ed (r = 0.92), suggesting that sigma ed is a factor for determining left ventricular end-diastolic stiffness. Left ventricular volume can be increased in patients with low sigma ed by atrial contraction, achieving good atrial contribution. Left ventricular volume will be little increased by atrial contraction in patients with elevated sigma ed despite significant increase of left ventricular end-diastolic pressure, resulting in diminished atrial contribution.(ABSTRACT TRUNCATED AT 250 WORDS)