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Biomedical subjects

B Diebold

Publications and source records attributed to B Diebold.

72 records · Page 4Linked to original sources
PubMed1983

[Doppler echographic study of placental circulation of the fetus of normal and hypertensive mothers].

Foetal blood velocity wave forms, as recorded in chorionic vessels by pulsed Doppler ultrasonography, reflect vascular resistance in foetal placental circulation. The minimal-to-maximal velocity ratio provides an index of vascular conductance; the higher the minimal velocity (positive forward diastolic blood flow), the lower the vascular resistance. In the present study, this index was the same in pregnant women with normal blood pressure (n = 19) and in those with pregnancy-induced hypertension (n = 12); however, it was significantly lowered (p less than 0.001) in pregnant women with essential hypertension (n = 9). In the population of women with normal blood pressure and pregnancy-induced hypertension, a positive correlation (r = 0.71), was found between index value and gestational age, indicating a progressive fall in placental vascular resistance. All placentas from these 31 women were histologically normal except two which showed one single marginal infarct less than 1 cm in diameter. In the group of women with essential hypertension, the 6 placentas examined were pathological, with multiple chronic infarcts, placental growth retardation and maceration. Thus, pulsed Doppler ultrasonography should be used for early detection of placental vascular damage and for improved surveillance of pregnancies complicated by maternal vascular diseases.

Blood Flow Velocity↗
PubMed1983

Myocardial map derived from two-dimensional echocardiography: reproducible and standardized description of infarction topographies.

The aim of this study was to improve the reproducibility and the standardization of the topographical assessment of myocardial infarctions in routine two-dimensional echocardiography. A myocardial map of the left ventricle was derived from a necropsy study of normal human hearts; interventricular grooves and papillary muscles were used as anatomical landmarks defining 16 segments with similar planimetered surfaces. A reporting sheet was prepared, with diagrams of standardized echo sections and with a map showing the position of the corresponding outlines. The echocardiographic method consisted in identifying on each section the regions without systolic thickening, and displaying the results on the map, until a coherent picture of the abnormal areas was obtained. Interobserver reproducibility was studied in 50 consecutive patients with prior myocardial infarction; segments were classified as fully abnormal, partly abnormal, non-visualized, and normal. Among the 800 segments there were 1% severe and 12% moderate discrepancies; discrepancies were significantly lower for segments with confrontation in two different sections intersecting on the map. A classification of infarction topographies was obtained in 100 consecutive patients; it was compared with the data of two reanalysable pathologic series from the literature; a similar presentation of the results showed similar typical patterns of myocardial involvement, for which a nomenclature was proposed. A myocardial map may be used to provide a simple and reproducible description of infarction topographies; the results obtained lead us to recommend an echocardiographic standardization of ventricular segmentation and of nomenclature of infarction topographies, similar to that of pathological studies.

Echocardiography↗
PubMed1983

Non-invasive quantification of aortic regurgitation by Doppler echocardiography.

This study was undertaken to assess the contribution of Doppler echocardiography to the quantification of aortic valve regurgitation. Ultrasound examination was performed by recording aortic arch blood flow from the suprasternal notch. A non-invasive index of valve regurgitation was obtained by calculating the ratio between the maximal amplitude of forward flow during systole and the amplitude of retrograde flow during diastole measured at the onset of the R wave of the electrocardiogram. This index was compared with semiquantitative data derived from supravalvular aortography in 93 patients. In pure aortic regurgitation (67 patients) the results showed a high correlation coefficient between Doppler and angiographic estimates. In cases of associated aortic valve stenosis there were problems in the accurate estimation of systolic blood flow which led to global overestimation in general of the degree of regurgitation and considerable lack of precision in individual patients. But in general Doppler echocardiography appeared to be a successful technique to quantify pure aortic regurgitation.

Adolescent↗
PubMed1983

Correlation between velocity measurements from Doppler echocardiography and from M-mode contrast echocardiography.

The slope of an individual contrast trajectory on M-mode contrast echocardiography represents a physiological variable similar to that measured by Doppler echocardiography: the projection of the intracardiac velocity vector in the direction of the sound beam. To test the hypothesis that M-mode contrast echocardiography slope measurement can yield information quantitatively similar to Doppler measurements, we performed both simultaneously in 11 normal volunteers. A pulsed Doppler unit capable of simultaneous M-mode and Doppler display was used. Contrast was obtained by intravenous injection of 5% dextrose. Two independent observers measured velocity simultaneously by both techniques at eight to 16 points per subject. One observer repeated the measurements a month later. All subjects had contrast, and 10 had sufficient quality tracings for simultaneous Doppler and contrast slope measurements. The correlation between velocity measurements by both techniques was good, though velocities by Doppler echocardiography were less than by M-mode contrast echocardiography. We conclude that the component of flow velocity towards or away from the transducer can be measured from M-mode contrast trajectory slopes as well as by Doppler echocardiography. M-mode contrast echocardiography may provide a practical method for verifying or calibrating Doppler measurements in vivo.

Adult↗
PubMed1983

Quantitative assessment of tricuspid regurgitation using pulsed Doppler echocardiography.

Tricuspid valve regurgitation was assessed quantitatively by measuring blood flow velocity in the vena cava using a pulsed Doppler velocimeter. A non-invasive index of regurgitation was obtained by calculating the ratio between the maximum amplitudes of the systolic and diastolic components of the velocity curves. The index was compared with the angiographic grading of regurgitation in 70 patients after right heart catheterisation; the results were closely correlated. Using the Doppler index the differences between the groups defined according to their angiographic grade were significant. Thus measurement of blood flow velocity in the vena cava appears to quantify accurately the severity of tricuspid regurgitation.

Adolescent↗
PubMed1982

[Non-invasive study of aortic insufficiency by Doppler echocardiography].

The possibilities of diagnosis and quantification of aortic regurgitation by pulsed Doppler analysis of blood flow in the aortic arch were examined in 60 patients aged between 9 and 67 years old. Aortic flow curves were recorded from the suprasternal area with the sample volume positioned at the junction of the horizontal part of the aortic arch and the descending aorta. Normal flow curves are characterised by an anterograde systolic wave with a brief proto-diastolic reflux. In aortic regurgitation holodiastolic reflux is observed. An index of regurgitation may be calculated from the ratio of the amplitude of end diastolic reflux measured on the R wave of th ECG and the maximal amplitude of anterograde systolic flow. This ratio eliminates the factor related to the incident angle between the ultrasound beam and the direction of blood flow. The values of this ratio were compared to the semi quantitative assessment of aortic regurgitation from ascending aortic angiography. The only false negatives were observed in patients with negligible regurgitation (grade I). One false positive result was obtained in a patient in whom it was difficult to obtain the recording and in whom the value of the ratio was very low (0,02). Global specificity was 91 p. 100 and sensitivity was 82 p. 100. The sensitivity for average or severe regurgitation was 100 p. 100. The correlation coefficient between the Doppler index or regurgitation and the semi quantitative angiographic estimation was 0,69. In patients with pure aortic regurgitation the correlation reached 0,85 (p less than 0,001). The differences between the different groups then became highly significant.

Adolescent↗
PubMed1981

Non-invasive diagnosis of mitral regurgitation by Doppler echocardiography.

The value of Doppler echocardiography for the non-invasive diagnosis of mitral regurgitation was studied blindly in 161 consecutive invasively investigated adult patients. Regurgitation was graded from 0 to 3 at selective left ventricular angiography. The Doppler echocardiographic examination was considered to be positive when a disturbed systolic flow was found within the left atrium behind the aorta or the anterior leaflet of the mitral valve. The test was considered to be negative in the absence of a regurgitant jet. The level of the signal to noise ratio was checked by the recording of the ventricular filling flow. The study was performed in 131 cases from the left side of the sternum and in 101 cases from the apex. There were no false positives and thus the specificity was 100 per cent. The 20 false negatives were all in patients with grade 1 regurgitation. Thus only some (33%) instances of mild regurgitation were misdiagnosed, and the sensitivity for moderate to severe mitral regurgitation was 100 per cent.

Adolescent↗
PubMed1979

Noninvasive assessment of aortocoronary bypass graft patency using pulsed Doppler echocardiography.

To evaluate noninvasively aortocoronary bypass graft patency, pulsed Doppler echocardiography was performed at the time of postoperative coronary angiography in 120 consecutive patients. Ultrasonic examination of 163 vein grafts was possible. One hundred twenty-seven patent and 14 occluded grafts were correctly identified. Eleven patent grafts could not be recorded, and 11 occluded grafts were falsely diagnosed as patent. The method had an overall sensitivity of 92% and a specificity of 56%. This high sensitivity level may be increased to almost 100% by enhanced technical skill and experience. The low specificity level, although the method must be tested in a larger number of bypass grafts, stresses the importance of correctly identifying other sources of diastolic blood flow. Diastolic flows from the superior vena cava, internal mammary veins, tricuspid valve, mitral valve and right ventricle may be eliminated by careful adjustment of the depth, site and size of the pulsed Doppler electronic sampling gate. Standard echocardiographic landmarks for avoiding confusion with the coronary arteries are also described.

Coronary Artery Bypass↗
PubMed1977

[Arrhythmias following closure of atrial septal defects. Apropos of 300 cases].

In a series of 300 cases whose atrial septal defects were closed (268 with ostium secundum, 27 with ostium primum, and 5 cases with both), arrhythmias were found in 60%. These were usually slow supraventricular arrhythmias caused by substitution (51%), and less commonly rapid supraventricular arrhythmias (27%), extra-systoles (16%), disorders of atrio-ventricular conduction of second and third degree and disorders of the auricle (6%). Conduction disorders were significantly more common (p less than 0.001) after closure of ostium primum (37%) than after closure of an ostium secundum (4.5%). Arrhythmias are most common during the first week (56%), and are usually of the slow type, and during the three succeeding weeks are markedly less frequent (31%) with a higher proportion (p less than 0.001) of the rapid type. No one anatomical type of ASD was complicated with arrhythmia more than the others. The slow type of arrhythmias occurred in the high ASDs, and the fast type especially amongst elderly patients. Longterm follow-up showed arrhythmias in 28% of patients with an ostium secundum defect. The factors influencing arrhythmias were age, cardiac enlargement, and the mean pulmonary arterial pressure. Arrhythmias were just as common in cases with a small shunt.

Adolescent↗
PubMed1977

[Non-invasive study of the patency of aortocoronary bypass with pulsed Doppler technic. Preliminary studies].

The pulsed Doppler effect is a non-invasive investigation technique based on the fact that the blood cells moving in a vessel on which ultrasound is incident cause a rebound of different frequency, according to their rate. This technique allows us to measure flow in a "measuring volume", whose size and depth are regulable. It is also possible to collect the signal from one or several aorto-coronary grafts, and to distinguish these from the sorrounding vasculature by their diastolic perfusion. This preliminary study (11 cases) is an attempt to formulate strict procedural criteria by comparison with follow-up arteriography of the grafts. The ease of performance of this investigation should, eventually, make it unnecessary to have to carry out repeated arteriography.

Blood Flow Velocity↗
PubMedDate not supplied

The age of the patient should be taken into account when interpreting Doppler assessed pulmonary artery pressures.

The impact of aging on the systolic artery pressure (SPAP) value is not well known. We selected 134 echocardiographic Doppler examinations considered as normal (presence of a sinus rhythm, absence of chronic obstructive pulmonary disease or pulmonary embolism, normal global or segmental wall motion, no right or left ventricular hypertrophy or dilatation, no significant valvular disease, no pericarditis), with a clearly measurable tricuspid insufficiency allowing us to measure the SPAP with the simplified Bernoulli equation. There was a highly significant (p = 0.0001) correlation (r = 0.47) between SPAP values and the age of the patient. SPAP increased progressively with age from 23 +/- 5 mm Hg between 20 to 29 years old to 32 +/- 6 mm Hg when 80 years old or more. The interpretation of the SPAP should take into account the age.

Adult↗
PubMedDate not supplied

MR tissue characterization of a right atrial mass: diagnosis of a lipoma.

A case of histologically confirmed benign lipoma of the right atrium is presented. Magnetic resonance imaging was successfully used to visualize and characterize the tumor previously detected by echocardiography. T1-weighted MR was superior to echocardiography and was in surgical agreement with examination in identifying the relationship of the lipoma to the right atrial wall, the coronary sinus, and the interatrial septum. Comparison of measurements of the tumor's signal intensities on T1- and T2-weighted images and T2 relaxation time with those of surrounding myocardium and mediastinal fat allowed a preoperative diagnosis of lipoma. Magnetic resonance may obviate surgical intervention in selected asymptomatic cases where the diagnosis of benign lipoma appears likely.

Aged↗