Effect of alteration in loading conditions on both normal and abnormal patterns of left ventricular filling in healthy individuals.

Doppler analysis of mitral flow provides a means of analyzing left ventricular (LV) diastolic function. While experimental studies have suggested that changes in left atrial pressure may affect the normal pattern of early diastolic filling, the effect of such changes on abnormal patterns of filling is unknown. Accordingly, the Doppler pattern of LV filling was analyzed in 20 subjects with LV hypertrophy (mean age 59 +/- 13 years, +/- standard deviation), in 25 healthy normal subjects (29 +/- 6 years) and in 11 elderly subjects (68 +/- 5 years). All underwent Doppler examination of LV inflow at rest and immediately after postural changes. In all 3 groups, head-down positioning increased early diastolic flow velocity (E) (p less than 0.001), and raised the E to late diastolic flow velocity (A) ratio (p less than 0.01). However, an abnormal E/A ratio never approached a normal resting value. Likewise, although E and the E/A ratio decreased significantly in normal subjects with head-up positioning, it did not become abnormal. The magnitude of change in E, A and E/A ratio did not differ among the 3 groups in response to postural changes. Thus, alterations of LV loading conditions alter the pattern of LV filling, whether normal or abnormal at baseline. The magnitude of change appears to be independent of the resting flow pattern. Although loading conditions may affect the Doppler pattern of filling, simple changes in venous return do not "normalize" an abnormal pattern, nor do they "abnormalize" a normal pattern.