Biomedical subjects

W el Yafi

Publications and source records attributed to W el Yafi.

7 recordsLinked to original sources

PubMed1994

A new Doppler imaging measurement in aortic stenosis: the contour length of the jet origin flow area. Relationships between both, with usual Doppler data and left ventricular hypertrophy.

Planimetry of stenotic aortic jet origin flow areas was performed using transthoracic Doppler imaging, with measurement of the contour length of flow areas and calculation of a contour/area (C/A) Doppler ratio on a group of 75 patients with aortic stenosis ranging from 0.27 to 2.44 cm2. The purpose was to study correlations of these data with the usual Doppler data and with left ventricular hypertrophy. The "r" coefficient between planimetered flow areas and those calculated by the continuity equation method was 0.89. Mean values (SD) of data were: areas: (planimetry) 1.00 +/- 0.53 cm2, (continuity equation) 0.91 +/- 0.42 cm2, contours: 5.6 +/- 1.6 cm, C/A: 0.66 +/- 0.25, maximal and mean pressure gradients: 68 +/- 34 and 37 +/- 21 mmHg, left ventricular hypertrophy: 138 +/- 30 g/m2 BSA (vs. 100 +/- 18 in normals). All values except age, gender and BSA, differed significantly (p < 0.001) between areas below or over 0.85 cm2. Other correlations between parameters were significant (p < 0.01 to 0.001), but with lower "r" coefficients due to widely scattered individual values. Contours increased much less rapidly than areas did, and were correlated with left ventricular hypertrophy only when coupled in the C/A ratio, with a higher "r" coefficient (0.62) than areas alone (0.52). Study of both areas and contours helps to approach the geometry of the orifice. This suggests that the individual geometry of the stenosis might weigh on the left ventricular mass growth, as an associated factor for a given decrease in stenotic area.

Adult↗

PubMed1994

Relationships between contour and/or contour/area ratio at Doppler and left ventricular hypertrophy in patients with significant aortic stenosis.

Planimetry of the stenotic flow areas using Doppler imaging of jet origin was performed, together with the measurement of their contour and a calculated contour/area (C/A) Doppler ratio, on 38 adult patients with significant aortic stenosis (0.27 to 0.85 cm2). Echo measurements of left ventricular hypertrophy (LVH) were also performed to study the differences in LVH according to the areas, even in case of smaller areas. This led to lower mean values of LVH (p < 0.001) in this group, and to a correlation coefficient at 0.18. The smallest areas were generally rounded and had a high C/A ratio. Contour was regular in half of areas over 0.5 cm2. It increased less rapidly than areas increased, leading to a decreased C/A. The other half, of a similar range of sizes, had a markedly increased irregular contour, entailing a C/A > 0.8. The highest mean value in LVH was found in this subgroup. Correlation coefficients vs. LVH were 0.43 for contour, and 0.32 for C/A ratio. Diagnostic reliability of a C/A > 0.8 for an LVH > 150 g/m2 BSA ranged from 55 to 70%. In conclusion, the study suggests that contour length weighs on LVH development when stenoses are significant, and should be coupled with area measurements. Figures also suggest that other factors intervene, requiring further study.

Adult↗

PubMed1994

[Time changes of mitral regurgitant jets: a 4th dimension for Doppler evaluation of the severity of mitral regurgitation].

The quantitation of mitral regurgitation is based on measurement of the maximal jet area by colour flow mapping. Discrepancies have been reported with the possibility of significant temporal variations of jet size. The aim of this study was to determine whether evaluation could be improved by taking these variations into consideration. Three dimensional Doppler colour flow mapping by combining measurements of length, height and width of the jet in two orthogonal planes, in order to obtain a global index of regurgitation, was undertaken in 40 patients with angiographically documented mitral regurgitation classified in three degrees, mild, moderate and severe. Two-dimensional Doppler with colour M-mode was performed in each patient analysing early, mild and late systole. In the absence of significant temporal variation, assessment was based on measurement of maximal jet area alone (maximum global regurgitation index). When there were significant temporal variations, the index was calculated during each phase of systole and the values averaged to obtain a mean global regurgitation index. Temporal variations were observed in 14 of the 40 patients (35%), mainly in mild and moderate regurgitation. Significant differences were noted in the values of maximal (p < 0.01 to 0.001) and mean global regurgitation indices (p < 0.001 to 0.0001) between each degree of severity. A paired study demonstrated significant differences between the two indices in mild (p < 0.01) and moderate regurgitation (p < 0.05). Assessment of the severity of mitral regurgitation was satisfactory in 65% of cases using the maximal global regurgitation index with 14 overestimations, all in cases of mild and moderate regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)

Echocardiography, Doppler↗

PubMed1991

[Characteristics of jets in adult bicuspid aortic valve by color Doppler imaging].

Color flow mapping of 15 adults with bicuspid aortic valves confirmed angiographically and at surgery comprising 8 regurgitations and 7 stenoses was analysed, retrospectively in 12 cases. The object was to detect any special features of the jets of this congenital abnormality. The site of emergence of the jet at the aortic orifice and its direction in the left ventricle were studied in the long axis, short transaortic and left ventricular axes by sequential analysis. Two types of regurgitant jet were observed: eccentric anterior origin (5, Type I), eccentric posterior origin (3, Type II), extending towards the structure opposite to their origin in the left ventricular outflow tract. In cases of stenosis, the cross-sectional view of the jet had an almost transverse slit-like appearance extending from one side of the aortic orifice to the other or an anterior or posterior eccentric oval shape. The Type I cases and the slit-like anterior stenoses had fusion of the coronary cusps whilst the Type II and posterior slit-like stenoses had fusion of the right coronary and non-coronary cusps. This preliminary study suggests that bicuspid aortic valves are associated with jet characteristics related to the abnormal commissural axis which allows diagnosis and precision of the anatomic type in adults despite the presence of calcification.

Adult↗

PubMed1991

[Chronology of maximal surface area and peak velocities of left heart valve flow jets using Doppler imaging. Clinical implications].

The aim of this study was to correlate the timing of the maximal surface area of the jet recorded by color flow Doppler and the peak velocities recorded by continuous mode Doppler with reference to the ECG R wave to determine whether standardisation of the chronologies of measurements was possible. A comparative paired study of these two parameters was undertaken in 44 subjects who had 55 left heart valvular lesions, all in sinus rhythm and, in cases of regurgitation, with pansystolic or pandiastolic regurgitant flow. The jets were examined in the inflow chambers of valvular insufficiency and at the origin of the jet in the short axis for stenotic lesions and aortic regurgitation, with planimetry of the cross sectional area in color Doppler. The correlation coefficient was 0.85 for aortic stenosis, 0.96 for mitral stenosis, 0.84 for aortic regurgitation but only 0.10 for mitral regurgitation. The mean values of the two chronologies were identical for stenotic lesions and did not differ significantly in regurgitation even at the mitral valve. However, the individual differences between the two chronologies exceeded 20 ms in 63% of aortic and 91% of mitral regurgitations. The maximal surface areas of the jets of 45% of aortic regurgitant and 91% of mitral regurgitant lesions were recorded between the onset of regurgitation and the peak jet velocity. The differences in chronology of the two parameters studied in cases of valvular regurgitation indicate the multifactorial nature of color flow jet imaging, probably associated with individual physiopathological variations.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1988

Doppler flow mapping and its comparison with the continuity equation method for quantifying aortic stenosis.

The flow-mapping technique, which detects and planimeters the area of systolic flow at the site of the aortic orifice, was applied to 59 patients with a stenosed aortic valve, all of whom underwent cardiac catheterization. The success rate was 93%. The correlation coefficient between the values of valvular areas obtained by Doppler and those yielded by the Gorlin formula was r = 0.93 (SEE = 0.12 cm2). The continuity equation procedure, with the use of the velocity-time integrals, was applied sequentially to 20 of the above mentioned patients. The success rate was 85%. The valvular areas obtained in these patients by the Gorlin formula correlated well with those obtained with flow mapping (r = 0.90, SEE = 0.14, standard deviation of the difference = 0.13 cm2), as well as with those yielded by the continuity equation procedure (r = 0.86, SEE = 0.17 cm2, standard deviation of the difference = 0.16 cm2). Furthermore, the data from both ultrasonic methods were satisfactorily cross-correlated (r = 0.92, SEE = 0.12 cm2). It is noteworthy that the values of aortic valvular area obtained by Doppler were slightly larger than those found using either the continuity equation procedure or the Gorlin formula. The authors conclude that the flow-mapping technique represents a reliable method for quantifying stenotic aortic valvular area and correlates well with the continuity equation procedure. It is therefore suggested that, whenever possible, both techniques should be used sequentially as a valuable and practical cross-checking policy.

Aortic Valve Stenosis↗

PubMedDate not supplied

Respective timing of maximal color Doppler jet areas and of peak velocity of jets in left-sided valvular lesions: clinical implications.

Time intervals between the R wave of the electrocardiogram and maximal dimension of jet areas of color Doppler and the R wave of the electrocardiogram and peak velocity of valvular jets of continuous-wave Doppler were compared by use of paired and correlative studies for a group of 55 patients with a total of 71 left-sided lesions. Mean values of both time intervals, mean difference, and its standard error were equal to zero for stenoses. Time intervals of 71% for mitral stenosis and 52% for aortic stenosis did not differ by more than 0.01 second; correlation coefficients were 0.96 for mitral stenosis and 0.85 for aortic stenosis. For regurgitations, differences in mean values and a mean difference with a standard error were found but remained unsignificant. However, the percentage of differences in time intervals below or equal to 0.01 second decreased to 35 for aortic regurgitation and 13 for mitral regurgitation, which showed the widest 95% range of differences. Correlation coefficients were 0.84 for the aortic regurgitation and 0.33 for mitral regurgitation. Thus the close relationship of time intervals suggests that standardized timing of area measurements at peak velocity is feasible for stenoses and remains under consideration for aortic regurgitation. Timing of measurements should remain empiric for mitral regurgitation.

Adolescent↗