Search

Abstract: Aims: To evaluate whether the peak systolic velocities of the displacement of the lateral mitral anulus (S a) and of the mid-portion of the interventricular septal wall (S m) correlate with measures of left ventricular load, left ventricular mass, and Doppler stroke volume in normotensive and hypertensive subjects without clinically overt cardiovascular disease. Methods and results: Tissue Doppler imaging was used to evaluate S a and S m in apical 4-chamber view; standard echocardiographic procedures were used to assess left ventricular structure and traditional parameters of systolic function (ejection fraction, stress-corrected midwall shortening, meridional and circumferential end-systolic stress); pulsed Doppler was employed to evaluate stroke volume. In 87 subjects meeting inclusion criteria, S a and S m were not significantly correlated either with left ventricular end-diastolic volume and end-systolic stress, or with stroke volume; in contrast, endocardial and midwall fractional shortening were lower with higher afterload, as expected. Fractional shortening at endocardium and midwall, and S m were lower with higher left ventricular mass. Mean S a and S m values were lower in subjects with low vs. those with normal stress-corrected midwall shortening, but low S a was not associated with lower stress-corrected midwall shortening in our study sample. Conclusions: While S a and S m might be indices of longitudinal left ventricular systolic mechanics, they should not be considered as measures of left ventricular contractility alternative to well-established parameters of systolic function, such as stress-corrected midwall shortening, in subjects at rest without overt heart disease. [Copyright &y& Elsevier]

Aims: To assess inter- and intra-study reproducibility of myocardial contrast echocardiography (MCE) imaging for quantitative measurement of myocardial perfusion rate in humans in ambulatory setting.Methods and results: In 20 subjects, we performed 2 MCE tests 20–40 min apart on the same day under the same standardized protocol, and evaluated single-reader between-study and between-reading reproducibility of assessment of indicators of myocardial perfusion rate, such as the slope of video-intensity change k, and the factors A (peak video-intensity) and B (background video-intensity after bubble destruction) and the product k×A. The region of interest was placed at the mid-posterior interventricular septal wall visualized in apical 4-chamber view. In a sub-analysis, we evaluated indicators of myocardial perfusion rate comparing subjects with normal vs. those with subnormal ejection fraction (EF). Inter-study reproducibility of assessment of k was relatively low (intraclass correlation coefficient = 0.36), whereas intra-study reproducibility was fair (intraclass correlation coefficient = 0.61). The parameters k×A and B showed higher reproducibility than the k (inter- and intra-study intraclass correlation coefficients 0.64 and 0.75, 0.74 and 0.91, respectively). For reference, reproducibility data of the depth of the region of interest, of EF and CO were excellent. k and k×A were lower in subjects with low vs. those with normal EF. Only k and k×A were lower in subjects with subnormal than in those with normal EF.Conclusions: The MCE-derived indicator of myocardial perfusion rate k×A showed fairly good between-study and between-reading reproducibility. [ABSTRACT FROM AUTHOR]