Biomedical subjects

F Proust

Publications and source records attributed to F Proust.

59 records · Page 4Linked to original sources

PubMed1981

[Sudden death during continous electrocardiographic recording by Holter's method].

The case of a 79 year old patient who died during continuous electrocardiographic recording by Holter monitoring is reported. There was a previous history of respiratory insufficiency, postero diaphragmatic myocardial infarction and left hemiplegia. Death occurred suddenly at home after defecation. Analysis of the recording showed multiple polymorphic ventricular extra-systoles, often occuring in doublets at the beginning of the record. Death was caused by a salvo of three ventricular extrasystoles triggering ventricular tachycardia which rapidly degraded to irreversible ventricular fibrillation. This major arrhythmia may have been due either to adrenergic stimulation from the effort of defecation or to acute myocardial infarction. This case underlies the value of Holter monitoring in the assessment of the gravity of an arrhythmia. It is also of interest because of the absence of an R on T phenomenon before the terminal event.

Aged↗

PubMed1978

[Recording of His potentials from surface chest leads using a computer].

Under certain circumstances it is possible to record His potentials using surface chest leads. These potentials have a very low intensity over the thorax, and must be separated from the "background noise" by an averaging technique. The desired activity occurs before the R wave and has a constant relationship to it; the potentials picked up by the chest leads are amplified, coded numerically, and presented to the memory store which accepts only those potentials which precede the R wave. It then summates the successive cycles, using a synchronising signal to ensure that they coincide. All this is carried out with an averager. In the 80 patients studied, a signal which seems very likely to reflect His activity was obtained in slightly more than a third of cases. The findings were correlated in 14 cases with those produced by invasive techniques, and showed that the main source of error was the after-potential of the P wave after a short PR interval--this occurred in one case; in the other 13 cases, the correlation was good. This method needs to be refined before it can be used clinically. It seems unlikely that it will replace the invasive technique which is so important for stimulation tests, and so necessary for studies of dynamic pharmacology.

Action Potentials↗

PubMed1978

[Continous electrocardiography recording in coronary insufficiency. Diagnostic value].

The accuracy of continuous 24 hour recordings (Holter's method) in the diagnosis of coronary insufficiency has been studied in 115 patients, by comparison with coronary arteriography. The technique was highly specific, but only fairly sensitive under the conditions of the study, because of the relative inactivity of the patients or the absence symptoms during the recording. It has allowed us to detect certain painfree or relatively painless forms of myocardial ischaemia which may be severe, and to have a clearer understanding of the effect of treatment. Comparison with the exercise electrocardiogram has shown inconsistencies due to the limitations of the two techniques. Holter's method is a particularly simple way of detecting coronary insufficiency, and is most useful when exercise tests are impossible or contraindicated.

Adult↗

PubMed1977

[The possibility of the detection of His bundle potentials using thoracic surface electrodes (author's transl)].

Under certain conditions, it is possible to record His bundle potentials from thoracic surface electrodes. These potentials, which are extremely weak on the chest wall, must be extracted from the "background noise" using an averaging method. The required signal being situated before the R wave, and at a constant distance from the latter, the potentials collected from the thoracic electrodes are amplified, numerised and despatched to a memory which retains only the values preceeding the R wave and produces a summation of successive cycles, causing them to coincide using a synchronisation signal. This is achieved with the aid of a correlator. Amongst 66 patients studied, a signal which most likely corresponded to His bundle activity was obtained in 1/3 of cases. Correlation obtained in 7 cases by the use of invasive techniques indicated that the principal source of error was the "after potential" of the P wave when the PR interval is short. This was seen in one case, correlation in the other 6 being good. The method will require further work before being available for clinical use, where its primary indication would seem to be the study of long PR intervals.

Amplifiers, Electronic↗

PubMedDate not supplied

Ophthalmologic aspects of pituitary apoplexy.

Pituitary apoplexy is an acute hemorragic or ischemic infarction in pituitary adenomas. The incidence in our series was 6.5%. Clinical diagnosis can often be difficult as the patient is frequently unaware of an existing adenoma (seven out of 11 patients). Therefore, the classic features of the syndrome must be known. They include sudden headaches, impairment of consciousness, endocrinological disturbances and sudden visual deterioration or oculomotor palsies. In this retrospective study from 1987 to 1994 of 14 patients presenting pituitary apoplexy there were 11 cases with visual abnormalities. Oculomotor palsies were more common (82%) than chiasmatic impairment (54.5%) and often revealed pituitary adenoma. CT-Scan and MRI examinations led to diagnosis, and emergency treatment (surgical removal by rhinoseptal approach or less often medical treatment) generally led to a regression of visual disturbances.

Adolescent↗