Search PubMed⌕ Search

Biomedical subjects

M Degeorges

Publications and source records attributed to M Degeorges.

At least 73 records · Page 4Linked to original sources

[Recording and data processing of electrical signals of the specific atrioventricular conduction pathways in man].

Signals of the electrical activity of the specific atrioventricular conduction pathways were recorded with an unipolar lead to obtain an exact time reference. The amplifier used had special characteristics: high gain settings (up to 300,000), very low noise levels, and wide filter range (2 Hz - 1,600 Hz). The low amplitude of the signals under study, of the order of a microvolt, and the wide filter range of the amplifier necessitated placing the patient in a Faraday cage. The signals recorded on magnetic tape were treated by a system of analysis for signal treatment. The method of averaging was used to extract the signal from background noise especially that arising from somatic muscle. The amplitude of the Hisian signal was much larger than that usually obtained with other methods. The intervals were determined with precision of the order of 1 millisecond. Frequential analysis of the signals gave another representation of the information contained in the time signals. This new representation seems to give better discrimination of the different zones of activation of the specific atrioventricular conduction pathways.

Adult↗

[Value and limitations of sequential technetium 99m angiocardiography in the detection, localization and quantification of left-right intracardiac shunts apropos of 110 cases].

A comparative study of the diagnosis of intracardiac left-to-right shunts by isotope radiography on the one hand and oxymetry, abnormal catheter trajectory and angiocardiography on the other, was performed on a series of 110 patients, comprising 12 normals, 46 valvulopathies or cardiomyopathies without shunts, 23 ASDs, 22 VSDs, and 7 other shunts. Intravenous injection of Technetium 99 m with scintigraphic imagery and interpretation of time-activity curves detected even small left-to-right shunts and appeared to be more sensitive than oxumetry. The estimation of the size of the shunt correlated well with oxymetry for VSDs but not for ASDs. The localisation of the shunt was more difficult. The atrial level of the defect was detected in some but not the majority of cases. The isotopic technique appeared unreliable in the presence of severe haemodynamic disturbances. The isotopic method is a quick means of detecting left-to-right shunts without measurable risk, particularly useful in the investigation of children and young adults thought to have left-to-right shunts.

Adolescent↗

[Assessment of the myocardial infarct size and kinetic study of the necrosis process by serial determinations of creatine kinase].

Assessment of the size of a myocardial infarct is important from a prognostic point of view, given the opportunities for surgical and pharmacological limitation of the process of necrosis. Serial doses of creatine kinase and its isoenzyme MB given every 4 hours for the first 48 hours of the infarct have allowed us to estimate the size of the infarct and to study the kinetics of enzyme liberation during necrosis. Unknown factors limit the sensitivity of this means of assessing the size of an infarct. The kinetic study showed that the enzyme is liberated by differing mechanisms.

Creatine Kinase↗

[Nitrous oxide analgesia in myocardial infarction (author's transl)].

Inhalation of the equimolecular mixture N2O - O2 rapidly achieves good analgesia in cases of coronary occlusion. This mixture was used with 51 patients (37 to 85 years old) with beneficial results on pain in 4 cases out of 5. This effect can be improved by giving a small amount of pethidine with the inhalation. In this way the respiratory depression of the full dose of narcotic analgesics is avoided. In halation of the mixture does not produce undesirable cardio-circulatory or respiratory changes. The oxygen content of the mixture increases patients' PaO2 without the risk of hyperoxia.

Adult↗

[Myocardial scintigraphy after injection of thallium 201 during exercise test. Results in 74 patients].

Thallium 201 is rapidly fixed by the healthy myocardium and its radiation detectable by a scintillation camera. It may be used to reveal and localise ischaemic zones after intravenous injection. In 74 patients undergoing an exercise test, the results of so-called effort scintigraphy were compared with effort electrocardiograms, coronary arteriography and scintigraphy after the injection of Thallium 201 at rest (rest scintigraphy). The results of effort scintigraphy show a high degree of agreement with those of the effort electrocardiogram and of coronary arteriography. It would appear to be of great value in the determination of the permeability of aorto-coronary by-passes.

Coronary Artery Bypass↗

[Scanning of the myocardium with pyrophosphate-technetium 99m. 367 cases].

Pyrophosphate-99m Tc injected intravenously is almost invariably fixed in the infarcted zone in transmural infarctions less than 8 days old. Fixation occurs in only 2/3 of cases of rudimentary infarction. The degree of fixation is more or less proportional to the size of the peak of creatine phosphokinase. After the 8th day following infarction, fixation is slight or nil. It is inconstant in pre-infarction syndrome or simple angina. This examination complements clinical, electrocardiographic and enzyme findings, in particular in the case of difficult diagnosis.

Angina Pectoris↗

[Interventricular communication, aneurysm of the membranous septum and acquired atrioventricular block].

Over a ten year period of a man 40 had a progressively increasing atrioventricular conduction defect, resulting from a ventricular septal defect with eventual cardlac failure due to persistant bradycardia. Intracavitary recordings showed the block to be situated distally, below the bundle of His. Cineaarteriography, and subsequent operation, showed an aneurysm of the membranous septum lying above a fibrous-edged ventricular septal defect. The aetiology of the block is discussed in the light of these defects; Haemodynamic trauma to the conduction pathways exposed in the inferior edge of the septal defect seems to be the most likely cause.

Adult↗