Annitta Morehead

Which physical factors determine tricuspid regurgitation jet area in the clinical setting

The visual assessment of jet area has become the most common method used in daily clinic practice to evaluate valvular regurgitation. Despite the high prevalence of tricuspid regurgitation, however, few studies have systematically compared TR jet areas with a quantitative standard. To evaluate this, 40 patients in sinus rhythm with tricuspid regurgitation were analyzed: 16 with centrally directed free jets and 24 with impinging wall jets. The size of the maximal planimetered color jet area (cm2) was compared with parameters derived using the pulsed Doppler 2-dimensional echocardiographic method: regurgitant fraction and the flow convergence method (peak flow rate, effective regurgitant orifice area and momentum). Mean tricuspid regurgitant fraction averaged 33 +/- 15%, peak flow rate 76 +/- 54 cm3/s, effective regurgitant orifice area 27 +/- 21 mm2 and momentum 21,717 +/- 15,014 cm4/s2. An average of 4-chamber, and long- and short-axis areas in free jets correlated well with regurgitant fraction (r = 0.81, p < 0.001), better with peak flow rate (r = 0.94, p < 0.001), effective regurgitant orifice (r = 0.92, p < 0.001) and momentum (r = 0.94, p < 0.001). The correlation was worse, but still significant, in wall jets. For the same peak flow rate, wall jets were 75% of the size of a corresponding free jet. Jet area measurement is a good semiquantitative tool to measure tricuspid regurgitation in free jets, which correlates well with regurgitant fraction and better with new parameters available from analysis of the proximal acceleration field. In patients with eccentrically directed wall jets the correlation with planimetered jet area was worse, but still significant.

Left ventricular diastolic dysfunction in lone atrial fibrillation determined by doppler tissue imaging of mitral annular motion

In this study, we sought evidence for an underlying atrial or ventricular myopathy in patients with paroxysmal lone atrial fibrillation using standard echocardiographic parameters in addition to Doppler tissue imaging of mitral annular motion. No impairment in atrial contractile function was found, but there was evidence for impaired diastolic function in these patients.

Two-dimensional Fourier filtration of acoustic quantification echocardiographic images: Improved reproducibility and accuracy of automated measurements of left ventricular performance

To determine the accuracy of Fourier filtration in removing the high-frequency component of noise from acoustic quantification (AQ) echocardiographic images, we processed 800 parasternal short-axis images obtained from 10 study subjects. M-mode tracings were also obtained and used as gold standard for correlating the results from raw AQ and Fourier-filtered images. Left ventricular short-axis diameters measured from the raw AQ and Fourier-filtered data were compared with the M-mode diameters (r = 0.91, p < 0.001 for raw AQ; and r = 0.96, p < 0.001, for Fourier filtered images). Fractional shortening showed better correlation between Fourier-filtered images and M-mode (r = 0.79, p < 0.03) versus raw AQ and M-mode (r = 0.33, p = 0.46). Best-to-beat reproducibility was also found to be better for fractional area change (r = 0.82, p = 0.01 versus r = 0.66, p = 0.77), peak area filling rate (r = 0.87, p = 0.004 versus r = 0.62, p = 0.1), and peak are emptying rate (r = 0.99, p < 0.0001 versus r = 0.19, p < 0.7) for Fourier filtered versus raw AQ. Our results indicate that Fourier filtration of AQ data results in more accurate representation of the true endocardial borders.