PubMed Health⌕ Search

Biomedical subjects

C Théry

Publications and source records attributed to C Théry.

At least 55 records · Page 3Linked to original sources
PubMed1978

[Recording the electrogram of the sinus node. Effects of the injection of tetrodotoxin into the artery of the sinus].

The cells of the SA node (SAN) are very resistant to the action of tetrodotoxine (TTX), a drug which. paradoxically, blocks depolarisation of the outer myocardial cells. Injection of TTX into the artery of the SAN brings about asystole; bur regular electrical activity, consisting of a slow wave of 200 to 300 ms duration, can still be picked up by an electrode placed on the SAN. This electrical activity, which can only be picked up over the SAN, and is resistant to TTX but blocked by acetylcholine, is interpretated as being the electrogram of the SAN. After the artery has been washed out by normal saline, the effect of TTX becomes progressively less; under these conditions, all degrees of sino-atrial block can be observed. Arising from a study of the phenomena of capture of the SA and AV nodes, of the effect of artrial stimulation, and of the time relationships between the various electrical events recorded, some hypotheses of the electrophysiology of the SAN and the sino-atrial conduction are put forward.

Acetylcholine↗
PubMed1976

[Electrical activity in the region of the sino-atrial node. Experimental study].

After finding the landmarks of the sino-atrial node in the dog by means of serial sections, the authors have recorded the electrical activity in the region of the sinus by means of bipolar and monopolar electrodes placed in contact with it. a)A preatrial wave has been recorded, and its origin is discussed. b) Mechanical destruction of the sino-atrial node is followed by the disappearance of this wave and the appearance of a slow junctional rhythm with a retrograde atriogram. c) When lignocain is applied directly to the sino-atrial node, the pre-atrial potential decreases and then disappears and the post-stimulation pause is prolonged. d) Clamping of the peri-sinus region gives rise to an incomplete block, followed by complete block, of the pre-atrial potential and the P wave. The post-stimulation pause remains normal. The disorders of rhythm which have followed these producedures may be regarded as constituting experimental models for sinus lesions and for sino-atrial block.

Animals↗
PubMed1975

[Aneurysms of the membranous septum. Apropos of 4 cases].

Three cases of aneurysm of the membranous septum were diagnosed in vivo. The fourth case was discovered at post-mortem examination in a patient who had a conductive disorder. These four cases give us reason to review the anatomical, clinical, radiological and haemodynamic features of this condition.

Adolescent↗
PubMed1975

[Atrio-ventricular block in Steinert's disease. Electrophysioligic and histologic study of the conduction system].

An anatomical study of the conducting pathways was carried out in a case of Steinert's disease complicated by a complete atrio-ventricular block with syncope. Electrical study of the potentials in the bundle of His located the block within and below the bundle. When the patient died, an anatomical study of the conducting pathways was carried out. There were foci of fibrosis mainly within the conducting system, but these changes were moderately marked only, and seemed to be the final stage of a disorder which was not itself visible optically. The basic underlying pathological process is probably biochemical, and the lesions seen microscopically are simply a late sign of the disorder.

Cardiomyopathies↗
PubMed1975

[Congenital atrio-ventricular blocks in infants. Histological study of the conduction system].

The authors present a clinico-pathological study of three cases of complete congenital atrio-ventricular block in the infant. In one case the disorder was familial, and the heart was macroscopically normal. In the other two cases, the associated abnormalities (complete discontinuity of the aortic arch in one, and situs inversus with a patent ductus and high VSD in the other) were not responsible for the conductive defect. This was explained after study of serial sections of the inter-atrio-ventricular septum; these showed an interuption or absence of the penetrating portion of the bundle of His associated, in one case, with agenesis of the atrio-ventricular node.

Female↗