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Biomedical subjects

G Abitbol

Publications and source records attributed to G Abitbol.

29 records · Page 2Linked to original sources

Non-invasive diagnosis and assessment of aortic valve disease and evaluation of aortic prosthesis function using echo pulsed Doppler velocimetry.

Non-invasive recording of aortic blood flow velocity patterns in the ascending aorta and in the arch of the aorta was performed in 12 normal subjects, 38 patients with confirmed aortic valve disease, and 13 patients with aortic prostheses using pulse echo Doppler velocity recordings. In normal subjects, the velocity recordings correlated well with those obtained by other authors using invasive procedures. In patients with aortic valve disease, specific abnormalities of the velocity curves were found to correlate well both with the type of lesion (stenosis or regurgitation) and its severity on a three-point scale. Both sensitivity and specificity were found to range between 80 and 94 per cent. A less accurate grading of severity was obtained from patients with aortic regurgitation by the detection of turbulence in the left ventricular outflow tract than from the appearance of the aortic velocity curves. In the studies of patients with aortic prostheses, anomalies of the velocity pattern could be found in the ascending aorta in 53 per cent but no abnormalities of timing was found. In spite of some technical limitations, pulse echo Doppler velocity recordings provide a new non-invasive, reliable, and reproducible approach in assessing the presence and severity of aortic lesions and demonstrating flow abnormalities produced by prostheses.

Adolescent↗

[Pulsed echo-Doppler diagnosis and evaluation of tricuspid valve, and interventricular and interatrial communication insufficiencies. Flowmeter study of shunts].

A group of 44 patients with a total of 48 cardiac lesions ( 22 tricuspid incompetence - TI - , 12 ventricular septal defect - VSD - and 14 atrial septal defect - ASD - , and two control groups of 20 normals and 23 patients with other cardiac disease , were studied by pulsed Doppler echocardiography ( PDE ) . The flow patterns recorded in the normal right heart were identical to those recorded previously during catheterisation . TI was diagnosed by the presence of an abnormal negative systolic wave usually associated with widening of the time interval histogram with a specificity of 82 % and a sensitivity of 86 % . An acceptable semi-quantative assessment of the severity of regurgitation was obtained in 83 % by comparing the amplitude of the negative systolic wave with that of the positive diastolic wave . Shunts were diagnosed by detecting septal or tricuspid turbulence with a sensitivity of 83 % and a specificity of 90 % . A satisfactory assessment of the size of the shunt was obtained in 90 % of diagnosed cases by assessing the pulmonary and infundibular flow patterns . A systolic wave starting with isometric contractions , followed by positive early and late diastolic waves and some intermediary negative oscillations of variable amplitude were recorded along the right side of the interventricular septum in 75 % of VSDs . In 78 % cases of ASD a large late systolic - early diastolic wave overriding the second heart sound , followed by positive mid and late diastolic waves of variable size , according to the heart rate , were recorded in the right atrium . In conclusion , PDE recording of blood flow patterns and turbulence in the right heart is a useful non-invasive method of diagnosis and assessment of these three cardiac lesions . It provides a valuable contribution towards the physiopathological study of shunt patterns in atrial and ventricular septal defects .

Adult↗

[Non-invasive exploration of valvular heart disease using Pulsed Doppler Flowmetry with echography (author's transl)].

A new method for diagnosing and assessing valvular heart disease is proposed, based on the analysis of transvalvular, pulmonary artery and aortic flow velocity curves recorded transcutaneously using Pulsed Doppler-echography. The normal tracings are presented and anomalies of the curves disclosed in 97 patients are analysed. It is concluded that this new, simple, non-invasive and repetable method is useful for diagnosing and assessing valvular heart disease, within limitations which are discussed.

Blood Flow Velocity↗

Applications of pulsed Doppler flow mapping to left sided cardiac valvular lesions.

The flow mapping procedure has been developed in parallel to the standard pulsed Doppler procedure. It has a different purpose--picking up flow signals at the site of lesions rather than calibrating velocities--and has its own methodology, developed within the last six years. On the basis of invasive correlations performed in 267 cases of valvular heart disease, we review the three-fold purpose of the flow mapping technique: diagnosing lesions, relying on the presence of flow anomalies; assessing their severity, relying on the spatial spreading of these flow signals; and identifying the site of the lesion, which is a specific advantage, relying on the anatomical location of these flow signals and/or on the direction of the jets. For example, using this technique, it is now possible to easily differentiate a cusp tear from a leak of a bioprosthesis, to measure the size of the leaks, and to reconstruct the image of aortic or mitral stenotic areas. These optimal results are only obtained using an appropriate methodology which mainly includes a) the selection of adequate two-dimensional short axis planes in order to explore the diseased valve in its entirety, because of frequent assymetrical orifices, and to pick up the jets at their starting point, b) measurements of the abnormal areas, c) when jets are studied, a three dimensional approach is required in order to cope with the three dimensional nature of the jet and to make available the calculation of three dimensional indices of severity.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Flow Velocity↗

Quantitative assessment of valvular regurgitations using the pulsed Doppler technique. Approach to the regurgitant lesion.

It is now possible with pulsed Doppler to grade the severity of aortic, mitral and tricuspid regurgitations on a quantitative basis. "Indices" were devised, using the measurement of the spatial extent of abnormal Doppler signals. For aortic regurgitation: (1) at the aortic valvular orifice area, by measurement of the regurgitant aortic valvular area and calculation of the valvular regurgitant "index". (2) In the left ventricle outflow tract, by calculation of an "index" combining information from two echographic (short and long axis) planes. For mitral regurgitation: by calculation of the total regurgitant "index" combining information from examination of the annulus in short axis, and of the left atrium in long axis view. For tricuspid regurgitation: at the tricuspid annulus, by averaging the depth of the reversal wave on two samples recorded using various echographic approaches. A group of patients with aortic (42), mitral (55) and tricuspid (57) regurgitation proven by invasive procedures, was investigated with this procedure using a 3 MHz two dimensional pulsed Doppler echo device. Correlative coefficients between the Doppler grading and that provided by independently performed invasive procedures on a three point scale, ranged between 0.66 and 0.88, with significant differentiation of mean values of indices (P less than 0.01 to P less than 0.001) for each grade of severity. Success in the Doppler grading of severity of the regurgitations requires (1) a sampling as close as possible to the lesion, and optimally at ther very site of the lesion, (2) the largest explorable area at the site of the lesion, (3) the relevancy of the selected Doppler parameter in order to take into account, as much as possible, the three dimensional configuration of the regurgitant jet. Moreover, this mapping procedure provides a pathophysiological insight of the regurgitant lesion for left-sided regurgitations.

Adult↗