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Biomedical subjects

H Boccalon

Publications and source records attributed to H Boccalon.

At least 127 records · Page 7Linked to original sources
PubMed1982

[Mercury gauge plethysmography. Sensitivity and specificity compared with standard phlebography (author's transl)].

Mercury strain gauge plethysmography with programme and ECG synchronous venous occlusion was tested in 14 normal subjects (28 lower limbs). The results obtained in the case of recent deep venous thrombosis of the lower limbs were compared with those of phlebography ni 39 patients: 26 proximal thromboses and 15 calf thromboses. Interpretation of the results must take into account the strict conditions under which the plethysmography was carried out: position of the subject and especially of the lower limbs and the technical characteristics of the apparatus used. Specificity was 96.4% for the group of normal subjects. Sensitivity calculated for all the cases of venous thrombosis studied was 97.5% whilst it was 100% for proximal thromboses (femoral and iliac).

Acute Disease↗
PubMed1982

[Use of computerized data processing in angiology in 1981].

A national survey involving 131 centres was conducted in 1982 to assess the extent of use of data processing in angiology in both medical and surgical departments. Findings demonstrated the recent nature of its employ, this being for less than 2 years in 2 out of 3 teams. There was evidence for the need for data processing reporting forms in as compact a lay-out as possible. Each team should estimate its possibilities as a function of the personnel, time, and financial means available, and determine its objectives before discussing the data processing programme.

Computers↗
PubMed1981

[Surgical revascularization of infarcted myocardial areas. Its effects on left ventricular function].

The results of twelve patients undergoing revascularisation procedures of infarcted myocardial territory alone were analysed quantitatively by planimetry in the right anterior oblique projection. Patients operated in the acute phase of myocardial infarction (2 cases) were distinguished from those with preinfarction syndromes (8 patients) and those with postinfarction angina (2 patients). Two posterior wall and ten anterior wall revascularisations were carried out by single bypass grafts (8) and double bypass grafts (2) with no operative deaths. The results were assessed 2 months to two years after operation (average: 6 months). Twelve of the fourteen bypass grafts were patent. Only one of the twelve operated patients, an anterior wall revascularisation, was considered a complete surgical failure: global left ventricular function and segmental wall movement progressively deteriorated with reduced contractility and velocity of fibre shortening. Improved contraction of both anterior and posterior walls was observed in the other 11 patients. The ejection fraction of the 9 patients with anterior wall revascularisation rose significantly from 47,1 +/- 10,5% to 56,3 +/- 3,5% and a similar rise was observed in systolic index (29,0 +/- 12,0 to 36,8 +/- 11,0 ml/syst./m2); the average akinetic end diastolic perimeter fell by 17%; segmental wall analysis of mean radial shortening and mean amplitude of excursion on the hemiaxes was improved, especially in the antero apical region: the corrected rates of mean excursion and average systolic work indices (33,2 +/- 15 to 41 +/- 13 gm/syst./m2) also increased. Surgical revascularisation of infarcted zones, made possible by new methods of cardioplagia and reliable circulatory assistance, may lead to improvement in global and segmental left ventricular function with minimal risk to the patient: this is thought to be due to an active mechanism and not to the passive process of scarring. Although a reserved attitude should be adopted in the acute phase of myocardial infarction, preinfarction syndromes and unstable postinfarction angina could well benefit from surgical management.

Adult↗
PubMed1981

[Therapeutic approach based on the results of examination of the vascular function in stage II arteriopathy of the limbs].

The therapeutic indications in stage II arteriopathy of the lower limbs take particular account of the walking perimeter. However, the lack of correlation on occasion between the walking perimeter and the haemodynamic data suggest the importance of an examination of vascular function, in particular in regard to the indications for restorative surgery. The medical approach may be advantageously adopted in cases where a walking perimeter in excess of 300 m on a horizontal belt is combined with an only slight decrease in the resting blood pressure (systolic index over 0.90) and a good stress tolerance (no great fall in the blood pressure). The surgical approach will be different in the case of lesions located above or below the crural arch. Sympathectomy may be envisaged in the case of thigh and leg lesions, accompanied by favourable haemodynamic indices (less than 50% fall in the blood pressure after effort), where the patient is handicapped by a short walking perimeter. Tests can be carried out to predict the effect of the sympathectomy. A collapse of the distal blood pressure, to values below 50 mm Hg, should suggest a restorative surgery. This approach is all the more likely to prove successful in the case of proximal lesions, where such lesions have affected the haemodynamic indices (a fall in pressure in the calf, accompanied by a satisfactory blood circulation higher up). Surgical intervention for the arterial condition should in this case give way to haemodynamic surgery.

Arterial Occlusive Diseases↗
PubMed1981

[The value of spectral frequency analysis by Doppler examination (author's transl)].

Arterial stenoses of moderate extent may involve modifications of the blood flow. Arterial shading is not always examined at the best incident angle to assess the extent of the stenosis. Spectral frequency analysis by Doppler examination is a good means of evaluating the effect of moderate arterial lesions. The present study was carried out with a Doppler effect having an acoustic spectrum, which is shown in a histogram having 16 frequency bands. The values were recorded on the two femoral arteries. A study was also made of 49 normal subjects so as to establish a normal envelope histogram, taking into account the following parameters: maximum peak (800 Hz), low cut-off frequency (420 Hz), high cut-off frequency (2,600 Hz); the first peak was found to be present in 81 % of the subjects (at 375 Hz) and the second peak in 75 % of the subjects (2,020 Hz). Thirteen patients with iliac lesions of different extent were included in the study; details of these lesions were established in all cases by aortography. None of the recorded frequency histograms were located within the normal envelope. Two cases of moderate iliac stenoses were noted ( Less Than 50 % of the diameter) which interfered with the histogram, even though the femoral velocity signal was normal.

Adult↗
PubMed1981

[Spectral analysis of frequencies by conventional Doppler effect examination of the supra-aortic trunks (author's transl)].

Using a directional Doppler (4 MHz) coupled to a frequency analyser, authors investigate the supra-aortic trunks on 90 patients documented by arteriography. The analyser is made of a 16 filter bank system giving a spectrum composed of 16 frequency bands within range of 160 Hz to 4,800 Hz. Data analysis is made on a computer using the comparison means test and the discriminant analysis. Authors compare frequencies on normal common carotid arteries between a group (N = 102) with internal and external carotid arteries free of lesions on one hand, and a group (N = 75) with stenosis or occlusion of internal and/or external carotid arteries on the other hand. They don't note any significant difference for each on of the 16 frequency bands. Comparison of frequencies between normal subclavian arteries (N = 115) and subclavian arteries with proximal stenosis or occlusion (N = 24) shows a significant difference concerning the following bands : F12, F14, F15, F16 (p = 0.05), F13 (p = 0.01). Comparison of frequencies between normal internal carotid arteries (N = 108) and stenosed internal carotid arteries (N = 57) shows significant difference concerning : F11 (p = 0.05), F7, F8, F9, F12, F13, F14, F15, F16 (p = 0.01). On the other side, the discriminant function distinguishes a normal internal carotid artery from a stenosed internal carotid artery in 90% of cases, whatever the stenosis degree is. A discriminant function, added to this analyser, could obtain a frequency analysis easier and less expensive than by fast Fourier transform.

Arterial Occlusive Diseases↗
PubMed1980

[Continuous assay of blood lactates. Application to the study of muscular work in the arteritis patient].

Ten normal and twenty arteriosclerotic patients underwent two successive static continuous exercise tests: - 4 minutes holding of 30% maximum power - 1 minute holding of 60% maximum power. Simultaneous recordings were made of: - The Xenon 133 washout curve of the anterior tibial muscle, to assess the ischaemia induced by exercise and to measure the duration of the hyperaemic phase; - The continuous lactate level in the femoral vein, using an original electrode specific for these enzymes. The following parameters were retained; - Resting, peak and the surface of accumulation of lactate after exercise; - The appearance time and the duration of accumulation of lactate with respect to the length of the hyperaemic phase. The following conclusions are drawn: - The differences in the height of the peak of the serum lactate. The duration and the surface of accumulation of lactate were only significant in obviously arteriosclerotic patients in whom exercise had induced ischaemia. - From the dynamic point of view: the hyperaemic phase always preceded the phase of venous accumulation of lactate, in all groups, peak lactates levels always occured during the hyperaemic phase and the length of the accumulation phase was 2 to 3 times that of the hyperaemic phase; in this respect, there was a significant difference between obvious arteriosclerotic patients in whom exercise induced ischaemia, and a group of other arteriosclerotic and normal patients.

Adult↗
PubMed1980

[Contribution of different methods for vascular investigation of arteriography of the limbs. Examinations in ambulatory patients and use of the vascular laboratory (author's transl)].

Various techniques are presently employed for noninvasive investigation of vascular function. The problem arises as the place of each method as a function of the medical surroundings and the pathological condition to be explored, and a multicentre survey was therefore conducted in 38 teams who were asked to define their activities. The most frequently used method is continuous ultrasonography (2 apparatuses per team), an 20 centres had available a mercury gauge plethysmograph. Lower limb resting pressure was measured in only 73% of centres, and an effort test conducted in 42%. Apart from medical staff, 58% of the teams included a laboratory technician, and 60.5% employed members of the nursing staff. The specialist (vascular surgeon, cardiologist...) is responsible for confirming the nature and effects of the vascular lesion, which requires the use of ultrasonography and distal pressure measurement. The laboratory for vascular exploration intervenes if surgery is contemplated or if diagnosis is not certain. Blood velocity and segment pressures are then determined. Effort and hyperemia tests can assist the decision to undertake reconstructive surgery.

Ambulatory Care↗
PubMed1975

Effects in rodents of a 1-month exposure to magnetic fields (200-1200 Gauss).

Under the conditions of the present study, magnetic fields ranging from 200 to 2000 Gauss strength have no toxic or histopathological effects on rats. The in vivo study and the histopathological results show no alterations of the vascular tissues, except for a nonpathological congestion of the spleen, and no intravascular thrombosis related to the experimental conditions. An unexpected observation was that the increase in body and organ weight of young rats was significantly greater in the groups exposed to magnetic fields. Therefore, no undesirable effects should be expected when magnetic fields within the prescribed safety limits of 200 to 2000 Gauss are applied to human subjects for several hours.

Animals↗
PubMed1975

[Muscular work and its hyperemic phase in the patient with arteritis].

Already users of a method of functional assessment of the muscular circulation in the patients with peripheral artery disease by Xenon 133, the authors propose a radical modification of the performance of the exercise test. A quantified exercise test leads to a new and more objective interpretation of the radio-active tracer elimination curve. This new method permits the measurement of the total quantity of blood which passed during the hyperhaemic stage and its time distribution. The aim of this test is to form an opinion on the tenacity and the efficiency of the supplementary mechanisms when there is an occlusion of the arterial axis.

Adult↗