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Biomedical subjects

R Grolleau

Publications and source records attributed to R Grolleau.

At least 109 records · Page 6Linked to original sources

[Congenital bundle-of-his focal tachycardias. Cooperative study of 7 cases].

The authors described seven cases of supraventricular tachycardia with atrio-ventricular dissociation, associated with the activity of an automatic focus in the bundle of His. These tachycardias, which appear at birth or are discovered at a very young age, appear to be congenital and sometimes familial, and are always isolated, having no associated cardiac abnormality. They give rise to cardiac failure, which is more marked when the rate is high (180-260/mn) and particularly resistant to treatment. The most effective form of treatment is amiodarone, almost always used in combination with digitalis. The anatomical abnormality, which was studied in the first case, is a contricting fibrosis around the main trunk of the bundle of His, and the appearances are reminiscent of those found in conditions of congenital atrio-ventricular block.

Amiodarone↗

[Right branch of the bundle of His. From morphology to its function].

A histological study of serial sections of 71 right branches of the bundle of His has enabled us to confirm the classical findings, but also lay emphasis on certain facts which are not so well known: --the presence or early collateral branches; --the concept of a septal nerve ending; --variations in its course associated with abnormalities in the relationship of the conus with the inferior part of the septum. Certain embryological and functional implications of these facts are noted.

Bundle of His↗

[Atrioventricular block and localized reentry into the trunk of the bundle of His].

In a patient with an AV block and a resulting variable rhythm, the coupled ventricular complexes with dissociated P waves on the standard tracing suggested a reentry into the atrioventricular area. Intracavitary investigation revealed: 1) a complete bidirectional AV block in the upper portion of the bundle of His (there being a proximal His potential with a fixed relationship with the dissociated atrial activity shown on the ventriculogram); 2) escape of the bundle of His low down, or of the beginnings of the branches, preceded by a distal Hispotential; 3) re-entry echos preceded by a third variety of potential in the bundle of His.

Bundle of His↗

[1st and 2d degree atrio-ventricular blocks caused by disorders of intra-auricular conduction].

In three cases collected among subjects with atrial anatomical lesions (two cases of "sinus disease" with partial atrial paralysis and one traumatic lesion of the right atrium in a WPW syndrome), atrial pacing demonstrated a considerable increase of the interval between stimulus and atrial response or intra-atrial Luciani-Wenckebach periods, for slightly increased pacing rates. Conduction changes into the right atrium explain apparently paradoxical variations of the degree of pre-excitation under pacing, in the case of Wolff-Parkinson-White syndrome.

Arrhythmia, Sinus↗

[Study of monophasic action potentials of the myocardium by endocavitary approach. Methodology].

The suction electrode makes it possible to record the monophasic action potentials (MAP) of the heart in situ. The technical characteristics of the tripolar electrode which we use are described. The O phase of the MAP is more prolonged than that of the intracellular action potential, but makes it possible to demonstrate the time of arrival of the activation wave in front of the exploring electrode. The phase 1-2 and the phase 3 have their characteristic contour in the right atrium and ventricle. The duration of repolarization makes it possible to assess the refractory period of different parts of the atrial and ventricular myocardium. The relatively simple and harmless method of recording of the monophasic action potentials by the endocardial route, both in the animal and in man, widens our investigation field of electrophysiology applied to the study of arrhythmias, of the repolarization disturbances and of the drug influences on the cell activity.

Action Potentials↗