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Biomedical subjects

M Amiel

Publications and source records attributed to M Amiel.

At least 91 records · Page 5Linked to original sources

[Radiology in renovascular hypertension from i.v. urography to digital subtraction angiography. A critical evaluation].

For the last 20 years, the value of radiology in renovascular hypertension (RVH) is well established from diagnostic and therapeutic points of view. However things are changing now due to a better appraisal of the incidence of RVH, new antihypertensive drugs, and new radiological procedures (digital angiography, percutaneous transluminal angioplasty). The approach now takes in account the mode of imaging for a better evaluation of the renal artery stenosis and costs of the procedures as well. Finally a new strategy has been set up for RVH patients management.

Angiography↗

[Primary coronary fistulas. Angiographic study of 21 cases].

A retrospective study of 21 cases of congenital primary coronary fistulae and a review of the literature underline the exceptional features of 2 of our cases and recall the main features of coronary fistulae. Coronary angiography (18 cases) or aortography (3 cases) confirmed the diagnosis in our 21 cases. Six of them involved the right coronary artery, 12 the left one, and 3 the two coronary arteries. Seven of them involved the right heart (2 right atrium, 5 right ventricle), 11 the main pulmonary artery, 2 the left heart (the left ventricle in both cases), and the last case was a coronaro-bronchial fistula. Our series comprised 11 men and 10 women; the mean age was 33 (range: 4 days to 67 years of age). The main presenting features were: murmur (7 cases), angina (7 cases), angina (7 cases), Stage II or III dyspnoea (5 cases). Clinical examination showed a systolic-diastolic murmur in 12 cases and a systolic murmur in one case. The chest X ray showed signs of left to-right shunt in 6 cases. The right heart catheterisation of 16 of the 19 left-to-right shunts confirmed the shunt in 9 cases. The 7 cases of coronaro-right cardiac fistulae drained directly (4 cases), by aneurysmal dilatation with diaphragm (3 cases); the 2 cases of coronaro-left-ventricular fistulae drained via microfistulae; the 11 cases of proximal coronaro-pulmonary fistulae drained mostly by an angiomatous plexus (9 cases).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Contribution of digital venous angiography to the evaluation of arterial hypertension. Cost evaluation].

Concerning 100 intravenous digital subtraction angiographies (IV DSA) performed for the study of arterial hypertension, the results are discussed according to two different achievements: diagnostic and economic. One hundred patients have been examined after the intravenous (IV) injection of contrast material, seventy times in peripheral and thirty times in central venous system. Out of 94 examinations that could be interpreted, 10 revealed stenosis of renal arteries higher than 50 per cent, one revealed fibromuscular dysplasia. IV DSA generally permits the correct study of renal arteries and compared to conventional angiography it gives only a small number of false negative results. However, the reliable study of intrarenal vascularisation can be obtained only by renal arteriography. The renal arteriography remains therefore necessary: when renal IV DSA gives insufficient data; to estimate the degree of stenosis in fibro-muscular dysplasia; to evaluate intrarenal vascularisation before renovascular surgery or angioplasty. To estimate the economic validity of renal IV DSA for the study of arterial hypertension, we have investigated: the actual cost of the examination for a department of radiology, compared with the cost of conventional examination; on the other hand, the influence of this examination on the duration of hospitalisation for evaluation of arterial hypertension. According to our investigation, this examination allows the average reduction of expenses for 180 F per patient with arterial hypertension, and shortens the time of hospitalisation for about one day. Owing to this diagnostic and economic contribution, renal IV DSA is becoming the first examination to be done for the evaluation of renovascular hypertension.

Angiography↗

[Angiography in bypass grafts of the left anterior descending coronary artery with the left internal mammary artery. Apropos of 100 control examinations with a maximum follow-up of 6 years and 8 months].

Ninety three patients underwent 100 angiographic control studies of a left internal mammary artery bypass of the left anterior descending artery. The controls were carried out between 11 days and 6 years 8 months after surgery. Seven patients underwent two control studies. The patients were divided into three groups:--60 early control angiographic studies (before 2 years);--16 late control angiographic studies (between 2 and 5 years);--24 very late systematic control angiographic studies (after 5 years). The patency rate of the arterial grafts was 99%. From the anatomical point of view, the arterial walls of the internal mammary artery appeared smooth and regular except in one case. There was no cases of bypass graft disease. The ratio of the diameters of the internal mammary and left anterior descending arteries was greater than or equal to 1 in 93% of cases. The adaptation of the diameter of the internal mammary artery to that of the left anterior descending artery is an early phenomenon as shown by statistical and repeat control studies. The number of remaining collateral vessels does not appear to have an effect on the diameter of the internal mammary artery. Stenosis at the site of anastomosis was observed in 16% of cases. This seemed to be favoured when the angle subtended by the two vessels reached 90 degrees. The haemodynamic changes of the coronary circulation (competition of flow, competition of flow in the distal vessels, reflux in the internal mammary graft) were comparable to those observed in aorto-coronary saphenous vein bypass.

Adult↗

Non-iatrogenic trauma of the coronary arteries and myocardium: contribution of angiography--report of six cases and literature review.

Six patients with coronary and myocardial trauma had selective coronary arteriography and left ventriculography. Of these, three patients with penetrating cardiac trauma presented with an occlusion of one coronary artery, including one fistula. Of three patients with blunt chest trauma, normal coronary arteries were observed in one patient, and obstruction of one artery in another; repeat coronary arteriography showed resolution of the previous obstruction in one patient. A review of the last 15 years of experience summarizes 38 angiography reports after coronary artery trauma. An analysis of the angiographic aspect of coronary artery damage is considered as an aid to understanding the traumatic lesion, its causes and its manifestations under the conditions of total or partial parietal damage of the artery, or parietal integrity.

Adult↗

Diminished osmotic and chemically induced haemolysis of human erythrocytes following exposure to contrast media molecules.

Radiocontrast molecules (RCM) used in coronaroangiography and/or urography diminished their osmotic fragility when they were incubated for 30 min with human erythrocytes. The shift of the osmotic fragility curve towards lower NaCl concentration is related to the hypertonicity of RCM, but in addition, at a given osmolality (100 +/- 5 mosm/kg), RCM at the concentration of 4-10% v/v increase the resistance to osmotic lysis or even suppress it. Similar protection is observed towards erythrocyte lysis induced by a detergent (saponin), polyenic antibiotic (filipin) or non-polyenic cholesterol-specific agent (digitonin). The effect is (1) proportional to the amount of RCM present, (2) independent of hypertonicity of the molecule, and (3) related to the nature of acidic molecules. A weak insertion of RCM into the erythrocyte membrane is suggested since it was suppressed by a single washing of the cells.

Contrast Media↗

[Correlations between coronary and ventricular angiography and the exercise test after myocardial infarction].

The aim of this study to assess the predictive value of exercise stress testing (ET) compared with coronary angiography-left ventriculography (CLV) in 102 patients undergoing physical rehabilitation (PH) after myocardial infarction (MI). The ET was optimised in its performance by the PH and in its interpretation by the selection of the parameters according to the site of MI. In anterior MI, angina (30%) and ischemic ST depression outside the acute period (35%) had little predictive value of multivessel disease which was demonstrated in 40% of cases; on the other hand, ST elevation in the same area as MI (65%) had an 88% predictive value for severe LV impairment which was found in 66% of cases. In inferior MI, ischemic ST depression (75%) more than angina (27%) was of greater predictive value (82%) for multivessel disease which was demonstrated in 59% of cases. The sensitivity was 97% and the specificity 64%; the LAD artery was diseased in 48% of cases. LV function was preserved in 63% of cases, but ET was not useful in the prediction of this parameter. In all cases of MI, the absence of ST changes predicted single vessel disease in 94%; ventricular arrhythmias (5%) stopped the patients reaching a discriminative exercise level but indicated poor LV function. The extreme values of heart rate and double product improved the correlations between ET and CLV. Therefore, ET may provide some of the information of CLV before the usual evolutive criteria and may help avoid this investigation in patients with favourable results, especially with inferior infarction. Although it has no absolute value, systematic ET is justified after MI as it enables the most severe cases to be distinguished from the most benign.

Adult↗

[Iodized contrast media. I. effector action on serum enzymes].

In vitro studies were done to examine the effects of contrast media on blood enzymatic activities. The results observed are very significant: in the most simple cases they result in a competitive or mixed-type type inhibition of these enzymes. In systems which involve two substrates and two products a Bi-Bi ping-pong enzymatic mechanism is transformed in Bi-Bi random enzymatic mechanism.

Contrast Media↗

[Stenosis of the left main coronary artery. Results of aorto-coronary by-pass in 67 patients (author's transl)].

Between 1970 and 1978 sixty-seven patients with > 50% stenosis of the left main coronary artery underwent aorto-coronary by-pass operation. The mean follow-up period was 54.7 months. Early and late post-operative mortality rates amounted to 3% and 9.2% respectively. Severe global alteration of left cineventriculography was the primary factor of survival (p < 0.01). The actuarial survival rates were 90.3% at 5 years and 84.5% at 9 years. All survivors had control ECGs. Late myocardial necrosis was rare (0.6 per 100 patient-years). 60.3% of the patients remained free from angina. Deterioration of the results mainly occured during the first 2 years but continued at a slower pace beyond the 8th year. Recurrence of angina was significantly less frequent in patients with isolated left main stenosis (p < 0.05) and when local conditions were not unfavourable to derivative surgery (p. < 0.01). On the other hand, the patient's age, sex, type of angina, history of previous infarction, number of risk factors and number of by-passes (the latter excluding possibly incomplete revascularisation) has no influence on the functional prognosis. Thirty-two patients had control, usually routine coronary arteriography 13.7 months on average after surgery. Overall patency was found in 85.9% and abnormal grafts in 16.7% of the cases. The main benefits of aorto-coronary by-pass, therefore, were a reduction in the spontaneous mortality rate of patients with left main coronary disease and a pronounced functional improvement.

Adult↗

Human serum albumin labelled with 99Tcm and 131I for total blood volume determination: A critical and comparative analysis in vivo and in vitro.

The increased plasma volume or total blood volume determined with radioactive tracers often have no physical or pathologic explanation. The plasma volume and blood dilution were simultaneously measured in 5 patients who had received human serum albumin labelled with 99Tcm or 131I. In each case and for each tracer, a biexponential dilution curve was obtained. The measured plasma volume was consistently higher after 99Tcm-labelled albumin. The results are correlated with the presence of non-protein artifacts arising from the labelling process and proteinaceous compounds arising from denaturation.

Blood Volume Determination↗

Effects of contrast media on circulating blood volume. A comparative investigation of various sites of injection.

Changes in the circulating blood volume following injection of different contrast media and at different sites have been measured in the dog. The results confirm that osmoreceptors in the right atrium play a role for changes in blood volume following injection of a contrast medium. The differential response to individual agents was mainly a function of their osmolality. Atropine appears to moderate the changes.

Animals↗

[Idiopathic aneurysms of the coronary arteries].

Two cases of multiple coronary aneurysms are reported in patients aged 15 and 25 years. The clinical presentation in both cases was myocardial infarction. The diagnosis was confirmed by the demonstration of rounded calcification at the border of the aneurysms on chest X-Ray, and multiple aneurysmal dilatations on selective coronary angiography. These two cases and the other 16 found in the medical litterature allow analysis of the clinical signs of idiopathic coronary aneurysms, generally these of acute coronary insufficiency. Two-dimensional echocardiography seems to be the most effective means of detecting this type of pathology. The incidence of coronary aneurysms during infantile periarteritis nodosa, and in Kawasaki's syndrome, very similar conditions affecting infants and children, suggest that these two diseases may play a role in the formation of coronary aneurysms in adolescents and young adults, which would therefore be sequellae of an inflammatory arteritis of childhood.

Adolescent↗