Biomedical subjects

W el Yafi

Publications and source records attributed to W el Yafi.

4 recordsLinked to original sources

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↗