Biomedical subjects
Publications and source records attributed to C Besson.
The case reported involved a large villous adenoma of the gallbladder with areas of carcinoma in situ, investigated by ultrasonography and CT. These imaging methods highly sensitive in the detection of such lesions are virtually non specific in terms of their nature and only the large size of the lesion should lead to suspicion of malignant change.
Explore the source record for details and available documents.
A haemodynamic and M mode echocardiographic study of 57 patients hospitalised for chronic, symptomatic 2nd or 2rd degree AV block was carried out after 3 periods of pacing, each lasting 2 hours : 1) sequential AV pacing ( SAV ) with a 200 ms delay, considered as the mode of reference; 2) sequential ventriculo-atrial pacing ( SVA ) with the same sequential delay, recreating equivalent conditions of 1/1 ventriculo-atrial conduction (VAC); 3) ventricular pacing (V) recreating complete AV dissociation ( CAVD ). The pacing rate was the same for each patient (89 +/- 9/min). In comparison with SAV , SVA caused much worse haemodynamic changes than V : large increases in mean atrial pressures (+161% and +64% in RAP and PCP respectively); "canon" atrial A waves which were poorly tolerated (mean amplitude 14 mmHg and 18 mmHg on the RA and PCP waves respectively); in some cases, a large fall in blood pressure was observed due to the failure of systemic resistances to increase and compensate for the constant decrease in pump function (mean reduction of 23% of cardiac index; 29% of LV work index). These changes are much more pronounced in diseased than in healthy hearts, especially in the presence of mitral or tricuspid regurgitation. Echocardiography showed the main cause of these haemodynamic changes to be a reduction in ventricular filling with significant reductions in LV systolic and diastolic dimensions, changes in the mitral valve echos (reduction in the opening and closing velocities, delayed closure), probably related to a decrease in transvalvular blood flow, and decreased regional contractility of the interventricular septum. These observations justify an increase in the indications of modes of pacing maintaining permanent atrio-ventricular sequence (VVI pacing at slow rates; AAI pacing, DVI or DDD pacing in cases of abnormal AV conduction with VAC, especially in cases of sick sinus syndrome with permanent bradycardia). These modes of pacing are particularly beneficial when the electrical abnormality is associated with a decompensated cardiac lesion, or with decreased ventricular compliance or mitral regurgitation.
Right ventricular involvement has been shown to be common in the acute phase of infero-posterior myocardial infarction. The aim of this prospective study was to assess the diagnostic and prognostic value of the different criteria obtained by clinical and paraclinical methods of investigation. Forty patients (35 men, 5 women: mean age 57,1 years) admitted consecutively with this type of transmural infarct without any other cause of acute or chronic volumic or barometric overload of the RV were investigated. In addition to clinical data, the following paraclinical investigations were carried out during the first three days of admission: ECG and vectorcardiogramme (VCG); transaminase levels (SGOT and SGPT), creatinine phosphokinase (CPK), alpha HBDH, serum creatinine, blood gases (pO2), M mode and 2 D echo, right heart catheterisation and cardiac output estimations, selective RV and pulmonary cineangiography centered on the LV in the monoplane 30 degrees LAO projection. Two groups of twenty patients were identified, comparable in age and sex, according to the angiographic extension of akinesia of the RV inferior wall: Group A: extensive akinesia (greater than or equal to 30 p. 100), Group B: very localised or no akinesia (less than 30 p. 100). Analysis of the results showed a number of features characterising patients in Group A: the high incidence of initial shock (45 p. 100 (A)/0 p. 100 (B] and signs of RV failure (85 p. 100/0 p. 100), higher SGOT, SEPT (p less than 0,05) and alpha HBDH (p less than 0,02) but not of CPK; much higher serum creatinine (p less than 0,01) and lower p02 (p less than 0,05); the ECG showed a high incidence (85 p. 100) and specificity (95 p. 100) of ST-T elevation in V3R and V4R, and also 2nd or 3rd degree AV block (60 p. 100/5 p. 100): there were no characteristic VCG changes. Catheterisation showed very significant increases (p less than 0,001) of mean RA, and RV end diastolic pressures, of the RA/mean pulmonary capillary pressure ratio and of Yu's index. There was a moderate increase in PCP (p less than 0,01), a drop in right ventricular systolic work index (RSSWI); adiastole was very common (90 p. 100) and very specific (95 p. 100); angiography showed an increase in RV end diastolic and end systolic volumes (p less than 0,05) and a fall in RV ejection fraction (p less than 0,05) but with a lot of individual variations; there were no significant differences between the two groups as regards the volumes, ejection fractions and p. 100 akinesia of the LV.(ABSTRACT TRUNCATED AT 400 WORDS)
Twenty-eight male subjects underwent a maximal exercise test on an ergometric bicycle, 13 untrained and 15 trained subjects. At rest and after this maximal exercise, indicated by the increase of the serum lactate and pyruvate acids, venous blood samples were taken to study the release of muscular enzymes (SGOT, SGPT, LDH, alpha HBDH, CPK, CPK MB) and myoglobin in the next 24 h (3 min, 30 min, 8 h and 24 h after the end of this test). The statistic analysis of the results shows significant increases in comparison with the values at rest, according to the enzymes and the groups of subjects, especially for CPK, SGOT, SGPT for which the results are homogeneous with a peak at the 3rd min and the 8th h in the three groups and for HBD and LDH in the groups of trained subjects. However these values remain most often within the normal limits. These results are compared with those of previous works on the same subjects.
The rise in serum myoglobin (MGB), total CPK (CKT) and its MB isoenzyme (CK - MB) was studied and compared over the first three days of acute myocardial infarction (AMI) and correlations were sought between the peak values of these three parameters and haemodynamic and biological indices of left ventricular function. Blood was taken from MGB (radio immunological technique), CKT and CK - MB (spectrophotometry) estimation every 2 hours for 24 hours and then every 6 hours up to the 72nd hour in 36 patients with AMI less than 12 hours old. On admission, this protocol was completed by a haemodynamic study (right heart pressures, systemic blood pressure, cardiac output measurement by thermodilution), arterial gases and ECG recordings. The average delays before the pathological rise, the maximal peak value and the return to normal were significantly shorter (p less than 0.001) for MGB (2, 6 and 25 hours) than for CK - MB (5,16 and 34 hours) or CKT (5,21 and 57 hours). The sensitivity of the diagnosis of myocardial infarction was not significantly higher with MGB than CKT or CK - MB either in the whole group (sensitivity of 91.6 p. 100 for MGB and 86.1 p. 100 for CKT and CK - MB) or in a subgroup of ten patients without transmural infarction (70 p. 100 for MGB compared with 60 p. 100 for CKT and CK - MB). A significant correlation was found between the peak values of MGB (p less than 0.02) and CK- MB (p less than 0.02) and the indices of left ventricular function (PCP, PAO2 and LVSWI). This was not observed with CKT. In conclusion, apart form technical problems which remain unresolved time-consuming investigation), serum MGB gives a much earlier and as sensitive a biochemical diagnosis of AMI as CKT and CK - MB. MGB and CK - MB are much better prognostic indicators than CKT as judged by the indices of left ventricular function. Finally, MGB estimation should be of particular value in the diagnosis of secondary extension of infarction.
Explore the source record for details and available documents.
A stress test was performed before and after by-pass grafts in 83 patients. Post-operatively, the number of painful stress tests fell from 68 to 28. Whatever the initial clinical picture (stable angina, anterior or inferior infarct), the improvements is significantly better when all of the lesions have been by-passed. Furthermores, there was no significant change in the maximal performance, but the appearance of pain occurred at much higher values, reflecting the improvement in coronary perfusion and the displacement of the point of appearance of ischaemia.
Explore the source record for details and available documents.
Evaluating a new diagnostic test is an essential step required before using a new examination technique. The information concerning the disease provided by the test must be examined in terms of diagnostic value and cost. A test can be evaluated using several indexes. For tests giving binary results, the main information indexes were defined and the calculation of the index was illustrated by an example. The sensitivity, specificity, the Youden index, and the positive and negative predictive values were presented together with the likelihood and odds-ratio. For tests giving quantitative results, the analysis of the ROC curves was discussed. Indexes were interpreted in terms of disease prevalence, the modalities (diagnosis, screening) for applying the test, the sampling technique for the tested population, the gain in diagnosis, and cost of the examination.