Digital subtraction high-frame-rate echocardiography detected prolonged regional relaxation index in coronary involved segments compared to normal segments (101.2 vs 36.3 ms, P<0.01).
Observational (n=89)
Can digital subtraction high-frame-rate echocardiography accurately detect regional left ventricular relaxation abnormalities in patients with ischemic heart disease?
Digital subtraction high-frame-rate echocardiography can accurately identify regional LV relaxation abnormalities in ischemic heart disease, even before systolic wall motion is reduced.
Absolute Event Rate: 101.2% vs 36.3%
p-value: p=<0.01
BACKGROUND: Because left ventricular (LV) diastolic function is impaired before systolic function in patients with ischemic heart disease and because ischemic heart disease is constituted of regional rather than global abnormalities of the left ventricle, measures of LV regional diastolic dysfunction, if possible, should provide the most sensitive assessment of the coronary involved region. The objectives of this study are to clarify whether high-frame-rate two-dimensional echocardiography, combined with digital subtraction image processing, may be used to visualize regional LV relaxation abnormalities in patients with ischemic heart disease and to clarify whether this technique provides a measure for the noninvasive assessment of the coronary involved region. METHOD AND RESULTS: In 30 normal subjects and 59 patients with ischemic heart disease, two-dimensional echocardiograms obtained at a rate of 60 frames per second were provided on line for digital subtraction analysis, with which digitized images were continuously subtracted on a frame-by-frame basis. The subtracted images were analyzed to determine the onset of the segmental outward motion of the LV wall in early diastole in each of 16 segments per subject. Regional relaxation index, defined as the interval from the second heart sound to the onset of outward wall motion, was significantly prolonged in the coronary involved segments compared with the normal segments (36.3 +/- 18.0 versus 101.2 +/- 34.0 ms, P < .01). The prolongation in the regional relaxation index was observed even in the coronary involved segments without reduction in systolic wall motion. When a cutoff level of 50.0 ms was used, coronary involved segments could be distinguished from normal or border segments with a sensitivity of 92% and a specificity of 81%. CONCLUSIONS: Digital subtraction high-frame-rate echocardiography may be used to visualize regional LV relaxation abnormalities in patients with ischemic heart disease. The time interval from the second heart sound to the onset of the segmental outward motion of the LV wall (regional relaxation index) obtained with this technique provides a noninvasive and accurate measure for assessing coronary involved regions.
Kondo et al. (Sun,) conducted a observational in Ischemic heart disease (n=89). Digital subtraction high-frame-rate echocardiography vs. Normal subjects/segments was evaluated on Regional relaxation index (interval from second heart sound to onset of outward wall motion) (p=<0.01). Digital subtraction high-frame-rate echocardiography detected prolonged regional relaxation index in coronary involved segments compared to normal segments (101.2 vs 36.3 ms, P<0.01).