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Biomedical subjects

G Abitbol

Publications and source records attributed to G Abitbol.

18 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↗
PubMed1990

[Analysis of prognostic factors in cervicofacial carcinology using the Cox model. An example of piriform sinus cancer].

Analysis of prognosis factors was performed on a surgical series of 34 of piriform sinus cancer, based on the use of a multivariate study according to the Cox model. The presentation is essentially didactic emphasizing the main points: how to collect data, what data to collect, and what judgment criterion to use. The authors detail the interpretation to be drawn from the analysis results using Cox model.

Aged↗
PubMed1989

[A new quantitative method for quantifying left heart jets by Doppler color imaging].

Quantification of valvular lesions by Color Doppler is based on jet measurements. The aim of this new method is to reduce some of the errors in these measurements: uncertainty in delimiting the colored areas of the jets; spontaneous beat-to-beat variations of the jets entailing interpretative difficulties. The first step was to determine the correlations between the colored areas and previously established single-gated Doppler criteria, retaining spectral criteria to define the borders of the jets, so overcoming some of the limitations of color Doppler. The association of these methods resulted in better discrimination between grades and a better correlation in 45 angiographically controlled mitral and aortic regurgitations than with color Doppler alone. In stenotic lesions, spectral criteria from single-gated associated exploration enabled localisation of the level for planimetry of the section of the jet at its origin visualised by color Doppler. Satisfactory correlations were obtained with the Gorlin surface area in a group of 43 patients with mitral and aortic stenosis. A coefficient of variation of 13 to 14 per cent was found with planimetry of the regurgitant jet in the upstream cardiac chamber. Uni-dimensional measurement decreased this variation to 6 to 11 per cent in the same patients. The largest decrease in variability (6 to 8 per cent) was observed in stenotic and regurgitant lesions with planimetry of the section of jet at its origin performed in held mid-expiration and so this would appear to be the best method. The guide lines and technological improvement associated with the physiopathological information provided by color Doppler should refine the quantification of valvular heart lesions.

Adult↗
PubMed1987

Application of Doppler flow mapping in assessing the severity of mitral stenosis.

The purpose of the flow mapping procedure is to pick up flow signals related to jets at the site of lesions, in order to delineate the cross-section of the jets. The pulsed Doppler procedure was applied to a group of 33 consecutive patients with mitral stenosis confirmed invasively in all cases and by surgery in 15 cases. The examination involved the recording of flow signals at the distal edge of the mitral oriface investigated in the short-axis view. Doppler criteria for required flow signals were the presence of a high-pitched tone and of a laminar spectrum, occurring at a definite timing in early to mid-diastole, i.e. at the period of the maximal atrioventricular pressure gradient. Planimetry of the flow area was performed and correlated with haemodynamic data using the Gorlin formula. The procedure was applicable in 32/33 patients. The correlation coefficient was 0.94, standard error of estimate 0.13 cm2, P less than 0.001. The mean difference between invasive and non-invasive measurements was -0.04 +/- 0.14 cm2 and the standard error of the mean 0.03 cm2. This new application of flow mapping provided reliable information for the later surgical procedure. It should benefit in future from improvements in spatial resolution and in signal to noise ratio.

Humans↗
PubMed1987

Detection of diastolic mitral regurgitation using pulsed Doppler and its implications.

Diastolic mitral regurgitation has been angiographically demonstrated in some patients with severe aortic regurgitation and/or nonobstructive cardiomyopathy. The purpose of this paper was two-fold: to study the feasibility of pulsed Doppler noninvasive detection of this unusually timed regurgitation on the basis of angiographic correlations in a group of 21 patients with such conditions and sinus rhythm with normal PR interval in 81% of the cases, and when diastolic mitral regurgitation was present, to study if it had clinical implications. Doppler detection was feasible in all cases and there were no false positive diagnoses. Comparison of haemodynamic data in patients without (group A) and with (group B) diastolic mitral regurgitation showed a significant increase in the mean values of pressures, particularly for the mean pulmonary artery and capillary wedge pressures (P less than 0.01 to 0.001), in group B. This study suggests that the recording of mitral flow velocity should be routinely performed in patients with such pathological conditions, since the finding of diastolic mitral regurgitation may have clinical significance.

Angiocardiography↗
PubMed1987

A new non-invasive estimation of the stenotic aortic valve area by pulsed Doppler mapping.

A new pulsed Doppler mapping technique has been used to measure the severity of aortic valve stenosis. The Doppler examination was performed at the site of the aortic orifice in the parasternal short axis echocardiographic view and the method was based on the detection of the area of systolic flow through the stenotic orifice. This area was derived by planimetry and the measurements obtained by the Doppler method were compared with the aortic valve area calculated at catheterisation according to the Gorlin formula. The method was applicable in 41 of the 44 patients studied. The Doppler data were consistent with the haemodynamic measurements even in patients with decreased cardiac index. It is concluded that this new application of the flow mapping procedure is reliable and is easily applied to adult patients with a wide range of clinical conditions.

Aortic Valve↗
PubMed1987

[Clinical value of the detection of diastolic mitral regurgitation by pulsed Doppler].

The reliability of pulsed Doppler echocardiography for the detection of mitral diastolic regurgitation was evaluated in 21 patients with severe aortic insufficiency and/or cardiomyopathy. Among these patients, 17 had sinus rhythm with a normal PR interval, while 4 had atrial fibrillation with short or normally lasting diastoles. Detection was negative in 10 cases (group A) and positive in the remaining 11 cases (group B). In all patients the data supplied by Doppler echocardiography were confirmed by angiography (100% sensitivity and specificity). A comparative study of right heart and left heart pressures in the two groups showed that group B patients had a special pressure profile, the most significant feature of which was an increase in pulmonary arterial and capillary pressures (p less than 0.01 and p less than 0.001 respectively). The diagnostic reliability of mitral valve diastolic regurgitation as to the presence of an abnormal mean pulmonary pressure was: sensitivity 80%, specificity 73%. Right heart pressures were either normal or very slightly elevated in group A patients. It is concluded that the presence of mitral diastolic regurgitation in patients with the pathology described indicates an unfavourable prognosis. This should be taken into account and lead to a systematic of mitral flow in these patients.

Aortic Valve Insufficiency↗
PubMed1986

[Doppler technics in the study of prosthetic valves].

The authors studied a group of 120 patients and a total of 137 valvular prostheses by ultrasonic pulsed Doppler (3 MHz). Fifty three of these prostheses were also investigated with continuous wave Doppler. Clinical, phonocardiographic and echocardiographic examination revealed 99 normal and 38 abnormal prostheses, the latter group comprising 42 dysfunctions (9 obstructions and 33 regurgitations), all confirmed by invasive studies. The lesions were graded into 3 degrees of severity. The methods used were the recording of velocity signals and two- and three-dimensional mapping in the pulsed Doppler mode, and the calculation of the haemodynamic parameters derived from measurements of blood velocity in the continuous wave mode. Pulsed Doppler correctly diagnosed 92 out of the 99 normal prostheses. The maximum systolic pressure gradient in aortic valve prostheses was 16 +/- 6 mmHg; the average early diastolic pressure gradient of the mitral valve prostheses was 10.01 +/- 3.34 mmHg, with a mean diastolic gradient of 4.52 +/- 0.71 mmHg and a mean pressure half time of 0.09 +/- 0.02 sec giving an average valve surface area of 2.45 +/- 0.57 cm2. The sensitivity and specificity of the diagnosis of valve dysfunction were 95 and 92 per cent respectively with a satisfactory evaluation of the degree of severity in 88 per cent of cases. In the 3 mitral valve prostheses with obstruction, significant abnormalities of pressure half time and value surface area were detected.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Valvar prosthetic dysfunction. Localisation and evaluation of the dysfunction using the Doppler technique.

Thirty patients with 33 mitral or aortic prostheses or both were examined using the pulsed Doppler technique combined with cross sectional echocardiography to study the applicability of the Doppler technique in the diagnosis and evaluation of the severity of prosthetic dysfunction and to assess the ability of the mapping procedure to estimate the site and the size of the prosthetic defect. The dysfunction was valvar regurgitation in 29 instances and stenoses in eight, all of which were confirmed by invasive procedures. The severity of the dysfunction was graded on a three point scale. A control group of 73 subjects with 88 normal prostheses also underwent pulsed Doppler and cross sectional echocardiography. The pulsed Doppler study followed the usual procedure for a valvar disease including two and three dimensional mapping for regurgitation. Eight patients also underwent a continuous wave Doppler examination. The diagnostic reliability of the pulsed Doppler technique was greater than or equal to 90%. The severity of the dysfunction was accurately assessed in 86% of cases. In the case of aortic regurgitation, mapping of the jets was performed as easily for prostheses as for native regurgitant valves. In the case of mitral regurgitation, the mapping patterns depended on the cause of the dysfunction. With valvar tears, a jet was detected at the centre of the annulus, and with paravalvar leaks eccentric atrial jets were seen opposite the site of the leak. The pulsed Doppler and the surgical findings correlated well for both the site of the dysfunction (16/20 (80%) patients) and the size of the leak (13/16 (81%) patients). Thus, despite some limitations, pulsed Doppler and particularly the mapping procedure provide sufficient information to give an accurate non-invasive assessment of prosthetic valve dysfunction.

Aortic Valve↗
PubMed1984

Calculation of pulsed Doppler left ventricular outflow tract regurgitant index for grading the severity of aortic regurgitation.

Measurement of the spatial extent of the regurgitant jet was performed in the left ventricular outflow tract (LVOT) with a 3 MHz two-dimensional echo-pulsed Doppler device, in order to assess the severity of aortic regurgitation on a quantitative basis. The procedure included: detection of diastolic disturbances in the LVOT and mapping of these disturbances in the LVOT. Length (L) and height (H) were measured with calculation of the product (L X H) in the long-axis view and width (W) in the short-axis view with calculation of the LVOT regurgitant index (LVOTRI) as follows: ([L X H] X W). Twelve normal subjects and a group of 83 patients, including 40 patients with aortic regurgitation proved by aortography, were investigated with this procedure. Diagnostic reliability ranged between 90% for specificity and 95% for sensitivity. Correlations between the grading provided by the LVOTRI and those provided by aortography on a three-grade scale showed a correlation coefficient between 0.67 (linear model, p less than 0.01) and 0.80 (exponential model), because of the high values of the index in cases of severe regurgitation. Reliability of the LVOT investigation in aortic regurgitation requires the use of information from two combined scan planes and quantitative rather than qualitative data. Main limitations of the procedure are due to the presence of associated mitral lesions.

Adolescent↗
PubMed1984

Quantification of left to right shunt in atrial septal defect using systolic time intervals derived from pulsed Doppler velocimetry.

Systolic time intervals derived from Doppler velocimetry measurements were used instead of direct pulmonary to systemic flow ratio measurements in adults with atrial septal defect to quantify left to right atrial shunts. Thirteen normal subjects and 25 patients with uncomplicated atrial septal defect confirmed by cardiac catheterisation were studied. The pulmonary to systemic flow ratio (Qp:Qs) expressing the shunt size was determined by the Fick method; in normal subjects the Qp:Qs ratio was assumed to be equal to 1.0. The pulsed Doppler analogue velocity recording of flow in the pulmonary artery and the ascending aorta was taken as indicating the ejection time of each ventricle and the Q wave of the electrocardiogram as indicating the onset of systole. From these measurements the ratios of the pre-ejection periods to the ejection times (haemodynamic ratio) were calculated for each ventricle and the ratios of each variable (pre-ejection period, ejection time, and haemodynamic ratio) were calculated for both ventricles. Significant differences were found between the normal subjects and the patients with atrial septal defect for all these ratios. When the Doppler findings and the Fick measurements of Qp:Qs were compared the best linear correlation coefficient was for the left to right haemodynamic ratio. It is concluded that the use of a ratio involving several variables, such as the pre-ejection period and the ejection time for both ventricles, improves the reliability of this method, which appears to be applicable in adults.

Adult↗
PubMed1977

[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↗
PubMedDate not supplied

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↗